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Technical writers earn as much as $101,399 annually, according to . Glassdoor Do you want to start earning money as a Web3 writer? I have gathered the thoughts of 10 Web3 technical writers to help you navigate this path. Whether you're looking for a job as a technical writer or looking for communities to help you grow as a technical writer, this is the blog post for you. What is Web 3.0? According to , Web3 is “read, write, and execute”. Tim Berners-Lee Web3 is the phase of the internet based on blockchain technology. It is a generation of the internet using cryptocurrencies, , and decentralization to give people control over their assets and their privacy. non-fungible tokens To fully understand what Web3 is, let’s look at the previous internet versions: Web1 According to developer , Web1 was primarily concerned with providing the general public with online content and information. Since consumers could only read information and not interact with it, Web1 was incredibly static. Bakti Aditya Web1 applications were Internet Explorer, Yahoo, and Netscape. Content creation was in its infancy, and there was little opportunity for interaction. Although Web1 couldn’t do much, consumers were happy because of features such as email and real-time news retrieval. Web2 also says that this is the version of the internet most of us know and use today. Web2 presented a whole new innovation from the previous version of the internet. Under Web2, users could not only consume but . Aditya create content on the internet themselves Along the way, four behemoths came to dominate the internet: Apple, Amazon, Facebook, and Google. Web2 also saw an explosion in the use of smartphones, and most of the internet use was through mobile apps and hardware built by these companies. Web3 Finally, talks about Web3 and says that this is the version of the internet we’re moving towards. Under Web3, the internet is shared online and governed by communities rather than being owned by centralized entities. Web3 relies heavily on , which is the technology that supports cryptocurrencies like Bitcoin. Aditya blockchain technology For more information about Web3, check out these articles: and Introduction to Web3 A Layman's Guide to the Decentralized Web. Who is a Technical Writer? According to the , a technical writer is someone who writes company documents. Technical Writing HQ These documents include user manuals, operating procedure guides, white papers, and product descriptions. Technical writers are in charge of simplifying complex content into simple instructions for the end user. As a technical writer, it is not expected of you to have technical skills, but communication skills will be your strong suit. How to Become a Web3 Technical Writer As a Web3 Technical Writer, your job is to create meaningful and informative content about the Web3 space for everyone. A lot of people want to be Web3 writers but are confused about where to start. In this article, I want to address your fear. I have interviewed 10 Web3 technical writers on how they started, the challenges they faced, and their most interesting career highlights. 1. John Fawole Alchemy's Blockchain Technical Writer. How did you get into Web3? I started in content writing. When I was crafting content for a client on an NFT marketplace, I included the tech stack to make it more solid. As a person, I always wanted to write about the geeky and technical aspects, so I went in-depth from Content writing into Web3 Technical Writing. Core Skills: Technical Writing, Community Management, Content Marketing, and SEO. What advice would you give to someone starting as a Web3 technical writer? It can be overwhelming at first, but you should be in a community to get direction. Always keep improving on your writing and learn how to do SEO. Learn how to code too to see what the technical aspect is all about. All in all, the hack is to learn little by little and to enjoy the process. 2. Gloria Chiemelu Technical Writer at TETU.io How did you get into Web3? I got into cryptocurrency out of curiosity. I started reading a lot about it, particularly from , , and the . After much research, I began pitching. Fortunately, someone needed a short crypto blog piece. I showed interest, and the person selected me for the role on Twitter. Binance Academy Investopedia Motley Fool Core Skills: Blogging and social media management. What advice would you give to someone starting as a Web3 technical writer? Do a ton of research! Web3 is a technical field, and you don't want to put half-baked content out there. 3. Victor Fawole Contributing Writer at Mirror . How did you get into Web3? I started by reading the Bitcoin and . After understanding the concepts, I started pitching my services via LinkedIn. One answered and I was hired to write on Web3. Ethereum documentation Core Skills: Content Writing and Community Management. What advice would you give to someone starting as a Web3 technical writer? They should first learn through blog posts and community forums on Twitter before thinking of earning. It is very possible to earn very high amounts if you connect with like-minded people, keep showing up publicly and stay consistent. 4. Ngozi-Olehi Munachimso Blockchain Technical Writer at Medium How did you get into Web3? I started by buying and holding coins in October 2021. But after the losses in the crypto market, I wanted to learn which coins to buy. I took a course explaining this concept, and that was when I got hooked. Core Skills: Content writing. What advice would you give to someone starting as a Web3 technical writer? Ask a lot of questions and stay among people who are well versed in this niche. Stay connected and stay consistent. 5. Tobi Amure Senior Marketing Advisor at Resistance DAO. How did you get into Web3? I had little to no experience with the subject matter when I started, but I used blogs like , , , and YouTube to source information. I used freelance sites like to source for gigs and that was how I got my first client. Coinmarketcap Bitcoin Magazine Cointelegraph Upwork Core Skills: Blogging, Technical Writing, Copywriting, and SEO. What advice would you give to someone starting as a Web3 technical writer? It wasn't rosy when I started. I’ve had ups and downs and lost some clients along the way, but I have learnt how to be better and how to position myself better in the industry. For newbies, just start. Get an Upwork account for pitching to clients, do your research, and follow industry leaders. Ask for advice and help where necessary. You will also need a LinkedIn account to follow C-level experts in the industry. Twitter can be so noisy at times, but LinkedIn helps to filter out the noise. Personal branding is important and knowing how to put yourself out there is important as well. 6. Gosia Szaniawska-Schiavo Content Team Lead at Tidio How did you get into Web3? It just piqued my interest due to the thousand blogs about the subject. As a content marketing professional, I dove in. Core Skills: Content Marketing. What advice would you give to someone starting as a Web3 technical writer? To be a successful Web3 writer, you must first be a good writer and then understand the specifics of writing Web3 content. There are lots of complicated concepts related to Web3, so your first task is to select a niche you want to develop in and gain expertise in. Learn extensively about Web3 in general and dig as deep as you can into your niche. Next, start gathering your portfolio. You can select a medium and start submitting your work there. Mirror, Medium, and Twitter are some of the most popular platforms for submitting and selling your articles. You will most likely become a valuable contributor to Web3 content if you have enough passion and curiosity. 7. Danny Trichter Co-founder, Accessibility Checker . How did you get into Web3? I got into Web3 out of curiosity. Looking through online platforms, blogs, and communities to learn all about the subject. Core Skills: Project Management, Social Media, and Online Advertising. What advice would you give to someone starting as a Web3 technical writer? Becoming a Web3 Technical Writer is not as difficult as one might think. The first step is to have a strong understanding of the . This includes the protocols, libraries, and tooling that make up the ecosystem. Once you have a good grasp of the technology, you can start writing about it clearly and concisely. Web3 stack There are several ways to get involved in the Web3 community and start writing about the technology. One way is to join a project or team and help contribute to their documentation. Another way is to start a blog or write articles about your experiences. This is a great way to share your knowledge with others and help them understand what Web3 is all about. Additionally, you should try to get as much experience as possible through internships and volunteering. There are many opportunities for technical writers in the Web3 space. With a little effort, you can become a valuable member of the community and help spread the word about this groundbreaking technology. 8. Edward Sturm Cofounder, Commit Club . How did you get into Web3? I started with Web3 in June 2017. My mentors realized decentralized technology and blockchain were about to change everything, and they wanted to get involved. It was a busy time, and I attended events organized by legends. One of these mentors also became obsessed with the idea of making a video game on the blockchain. We created the first crypto play-2-earn game after being inspired by . This was January 2018, 9 months before Crypto Winter, and we had a lot of attention and buzz. CryptoKitties The game featured battling, leveling up, and various rarities. We were ranked the top blockchain game for 2018 and 2019. During this project, I had to do a lot of technical writing, explaining the inner workings of the app and our progress to a hungry audience. I learned a ton during this period that I carry with me today. Core Skills: SEO, Social Media, and Marketing What advice would you give to someone starting as a Web3 technical writer? Technical writing is the concept of making technical ideas readable, actionable, and concise while also being detailed and instructional. This is reflected in the whitepaper for our current project, Commit Club, in which we are developing a decentralized commitment device. Web3 technical writing, like all things in life, requires consistency. I became good at it in 2018 when I had to use it frequently for our game audience. My advice for getting started is to summarize your technical learning in documents for yourself. This way, you can practice writing of a technical nature while also learning more about Web3. When you write, make sure to organize everything with great detail and nest ideas and categories so they can be easily called back upon. Importantly, you should do this every day for a week or two to turn this into a habitual skill. 9. Sadiq Isiaka Cofounder, MintyPlex How did you get into Web3? In 2015, I saw a movie called , which featured an adventure involving shady drug dealers starring rapper A$AP Rocky. I was so interested in the fact that Bitcoin was the mode of payment that facilitated the transactions. Then I took my time studying Bitcoin and all the concepts of cryptocurrency. Dope Fast forward to 2020: I bought Ethereum, Dogecoin, and some other cryptocurrencies. I just wanted to get involved in any blockchain-related project be it writing, design, or graphics. Most of the projects also involved writing, meeting new people, and connecting with friends. Core Skills: Project Management, Technical Writing What advice would you give to someone starting as a Web3 technical writer? The Web3 world is far different from Web2, so get involved and volunteer in your community. As a writer, you'll be explaining tough concepts to people. Learn how to research and how to communicate what you learn in a friendly manner. It all boils down to contribution, collaboration, and community. 10. Ivelina Dineva Head of Content at NFT Plazas How did you get into Web3? I first heard about NFTs from someone I met at a co-working space for digital nomads in Bansko, Bulgaria in 2020. I was immediately fascinated by it, although I had zero knowledge of crypto back then. The first NFT I ever saw was an NFT artwork by SlimeSunday on . Nifty Gateway I started learning more about NFT art specifically, as I had already been collecting physical art for many years. Anyway, I soon wrote for fun about NFTs, and then I used that article to apply for NFT and blockchain writing projects on Upwork. an article on Medium It was great timing because almost no one was writing about it at the time. That's where I connected with Chris, the CEO of NFT Plazas, and I went from being a part-time writer to Head of Content quite quickly. Core Skills: NFT Marketing What advice would you give to someone starting as a Web3 technical writer? I want to point out to aspiring writers, or anyone in any field, that you have to ASK for what you want! I stated that I want a full-time position and demonstrated that I am capable of much more. So just ask and show that you are amazing. Takeaways 1. Learn the basics. To be proficient as a Web3 technical writer, you need to learn the basic concepts around it. Examples are: What is Bitcoin, What is Web3. What is Ethereum, and so on. To learn these concepts, explore free and paid learning sites like , , , and more. Coinbase Cointelegraph Coursera 2. Be curious. A lot of the professionals were not experts when they started, but their hunger for knowledge kept them on their toes. In the same way, you need to follow Web3 experts, ask questions, and constantly learn about the space. . 3. Write sample articles As you learn about the concepts of Web3, you should start writing. When you write, you start gaining experience and feedback on your work. You don't need to become another Shakespeare. Just start writing about the things you have learned on platforms like Medium, LinkedIn, Twitter, and more. This would later serve as your portfolio. 4. Build quality friendships and connections. As the experts said, the connections you build on social media can greatly influence your Web3 journey. Most of them got their first roles by referral or by others giving them a chance to prove themselves. Make horizontal and vertical connections with those who are currently learning alongside you as well as those above you. 5. Be consistent. Even after you’ve landed your first role, don't relax. The Web3 world is so fast-paced and ever-changing. Keep building your writing skills, engage with other Web3 writers, and most of all, keep learning.

How to Become a Web3 Technical Writer: How These 10 Pros Did It.

The Evolution of Modern Medicine: Chapter I - ASSYRIAN AND BABYLONIAN MEDICINE

Building a successful search takes more than technical smarts, but if done right is one of the most rewarding products you could work on. Everything is a search problem. From finding the keys in our pocket (thanks, AirTag) to looking up a long-lost lover on LinkedIn — seeking things and answers is a problem that predates civilization. When historians look back at our lives, they will proclaim how this was the time when . Our era marks the transition from search being used for survival to one of expanding our knowledge. humans industrialized search on a scale that touched every facet of our lives It’s hard not to see the impact. An average person conducts ; more times than I can remember to drink water. three and four searches each day is the most website on the planet, logging 5.6 billion searches daily. Google.com dominant approximately We have been looking for answers to life’s questions for centuries, but . To cope with the newfound convenience, we have honed skills for sifting the informational zeitgeist and learning to pose questions in ways a machine can understand. it’s never been so easy, expansive, and quick to do so “You have people walking around with all the knowledge of humanity on their phone, but they have no idea how to integrate it. We don’t train people in thinking or reasoning.” David Epstein, Range Servers, algorithms, and programming languages aid us in this struggle, a compass for mapping the optimal route from query to knowledge. For those of us building such search tools, our problem is knowing that when our users search for anything, there are . So, how best to approach this? few guarantees we will provide relevant answers The secret to a great search Being an excellent search product team is the same as being a great team for anything else. The : Understand and help your users solve a valuable problem and work from there. principles are almost cliche backward When my team and I built our first search engine on (Reference management software for researchers), the key to our unexpected success was understanding that Mendeley search was not just about helping academics find research papers. What was important was , leading to improved user retention and product growth. understanding that finding relevant results for our users was key to a better onboarding experience Thanks to focusing on longer-term product impact, we . Instead, we concentrated more on the holistic user experience and prioritized , such as explaining result relevancy or assisting users with choosing better keywords. didn’t get distracted by arbitrary goals like optimizing result relevancy features that built trust Had we doubled down on search , I doubt we would have achieved our double-digit growth and engagement. vanity metrics like response speed or % of clicks in the first 10 results I’ve noticed that many who enter the field of search have technical backgrounds and t’s not hard to understand why. Search products are inherently more technical, speculative and experimental than many other user-facing features. Having the skills to navigate the technical complexities of search, so you understand its limitations and capabilities is . However, , which blinds us to opportunities. a significant advantage when planning and working with engineers people tend to over-index on this knowledge For example, when building our search, the goal was to help our users become more productive. Doing a good job, we reasoned would . As a result, everything we chose to learn, research, build and measure around search was based on those goals, not vanity relevancy metrics like DCG (Discounted cumulative gain — a fancy way of measuring the number of clicks on the first couple of results). increase user engagement, retention and satisfaction Our role is to . connect a love of the problem with the available technology We need to be technical enough to understand the vocabulary of engineers, but not so much as to place restrictions on our goals based on any present technical limitations. To combat this, I would instead , e.g. Graph databases and general language models. Aim to build a product roadmap in the medium-term future, and you will always be prosperous. recommend planning around any given technology trend rather than its current absolute that anticipates what is likely to exist The other thing to understand is that . Users provide many perspectives, which ensure the quality of results will be interpreted very differently. Rarely are there single correct answers for everyone (a bit like real life). . everything in search is speculative Our users could provide different satisfaction levels for the same results for the same query on the same day Finding peace with the ambiguity of search work means discovering ways to . The best way to achieve this is by focusing on skills that facilitate robust working methods and ensure strong teamwork. reduce uncertainty In other words, : communicating, empathy, leading without authority, having difficult conversations, storytelling, making decisions when you don’t have all the information, dealing with ambiguity, inspiring others, and connecting deeply with users. practicing the “art” of product management in search more valuable than the “science” I can’t emphasize enough not to fall into traps like ensuring response times need to be under 100 ms or results need to be 80% accurate or whatever three-letter acronym metric is currently in vogue: DCG, eDCG, Rank K, MAP. I mean, be , but shouldn’t let them dictate goals. We need to remain user-focused, not search-focused. aware of them In many ways, search products are a . Like any good product team, . sum of destructions we need to predict a little bit at a time and then verify If you find yourself stuck for solutions, the best advice I can offer is to approach complex search problems by . building a platform where people can provide their raw components and tailor them to their needs For our teams, that means creating clarity and access to relevant information that help people make autonomous decisions. For our users, that means building flexibility into our tools to allow users to identify novel ways of solving their problems. . Sometimes we just need to build the tools, features, and ways of working that enable us to do things independently. We don’t always need to understand all the complexities of a user’s problem Search is the Best Product Interestingly, search . changes our perception of the world and our ability to live within it It changes to text, changes reading (thank you snippets), how to understand, and even what it means to be literate. Our readers can now easily find connections that an author never intended. “Search engines have become sense making engines, helping to chart, connect and explore infinite textual maps.” , founder of Ness Labs Anne-Laure Le Cunff Really what a search is, is . a bunch of little problems with a bunch of little solutions Building such products brings the responsibility of knowing that . These are opinions from which we formulate praise for our friends and contempt for our enemies, our long-term projects, our deepest self-doubts, and our highest hopes. (Paraphrasing philosopher Richard Rorty, 1989) we enable anyone to form opinions that justify their actions, beliefs, and lives Our greatest challenge as search people is that users are messy. We have to work knowing that . The challenge becomes . user queries are highly variable and usually not well formulated understanding a user’s intent when even the user doesn’t know what they want Philosophy rarely rhymes with software engineering, but a big part of building a search is figuring out what your user means. In the hope of more clicks, I see teams building ever more complex personalization, semantic and segmentation models that aim to filter out irrelevance and boost the familiar. Morally, I believe this is a mistake. Recommender or historical click boosting solutions built into search . assume that users wish their future results to depend on historical behavior It’s an assumption that if executed over a long enough time and limits our ability to express ourselves. One of my favorite philosophers, Isiah Berlin, would call this an attack on our — the set of words we carry about that justifies our actions, our beliefs, our sense of the world, and our place within it). We would call this an “echo chamber”. robs individuals of optionality final vocabulary If you plan to do such things, always . , for example, released a feature that allows you to your recommendations. It’s not only good for society but also good for business. ensure you do so transparently Medium.com understand and refine I’ve found that the . “If your model will suffer from perfect transparency with customers, you’re in an unbeatable position,” venture capitalist Jesse Beyroutey. primary source of a company’s dominance is whether it designs its product and business model to be perfectly aligned with its customers’ interests not says Building a great search is the same as building anything else that’s great: assess the opportunity, then define what needs to be made. My day looks like many other product managers: I get up in the morning, check metrics, prioritize tasks for sprints, write user stories, refine with my team, and conduct research. . If you can fall in love with the problem, then being voracious in taking the time to learn and understand what makes search work becomes second nature. The qualities of a great search team are adaptability, optimism, and humility Here are some : resources I strongly recommend , Doug Turnbull and John Berryman (Book) Relevant Search , Max Grigorev What Every Software Engineer Should Know About Search , James Rubinstein Measuring Search: Metrics Matter , Daniel Tunkelang On Search Leadership James Rubinstein Search Product Management: The Most Misunderstood Role in Search? , Frode Hegland (Book) The Future of Text What’s so satisfying about working on search is . There are many exciting problems and pieces of technology to play with, plus, you get to work with intelligent people (engineers, analysts, data scientists). knowing that the tool you build brings people so much value Don’t feel discouraged if you don’t think you have the technical know-how for the job. . If nothing else, this is the most crucial skill I find technical PMs forget when working through tricky issues. Though in their defense, one could argue I’m simply being naïve and merely passing the hard work onto others. A great advantage non-technical product managers bring is a problem-first approach The of working with search is its ability to . The pace of change is fast, with new groundbreaking models or frameworks released monthly. There are many , and it’s to feel like the downside induce a sense of relative deprivation upon its makers technological distractions easy world is leaving you behind. Most of your daily work is and , deduplicated, synced, and working at scale. Plus, users will keep coming up with creative ways to break your service. less cutting-edge AI more keeping data up to date However, the great thing about . Every search solution can look and feel very different. search is it’s not a solved problem Doing a great job at search . How often can you say you were able to on something that achieved ? can mean the difference between a person having an informational revelation or missing a lifetime opportunity work that “No learner has ever found that he ran short of subjects to explore. But many people who avoided learning, or abandoned it, find that life is drained dry” Maria Montessori, Italian physician . Also published here

What it Takes to Build a Really Great Search Engine

In an era where the digital and physical worlds are becoming increasingly intertwined, the next wave of wireless communication technology—6G—promises to blur these boundaries even further. But how on earth do we deal with eavesdroppers? One of the advancements on this frontier is the development of Secure Full Duplex Integrated Sensing and Communications (ISAC), a technology designed to not only enhance communication capabilities but also to provide robust security measures against eavesdropping threats. As we venture into the possibilities of 6G, the concept of ISAC emerges as a beacon of innovation. ISAC envisions a future where communication systems are not merely passive transmitters of data but active sensors of their environment. This integration promises to open a plethora of applications, from autonomous driving to advanced remote healthcare, by leveraging the dual functionality of sensing and communication. However, with great power comes great vulnerability. The open nature of wireless communication systems makes them susceptible to eavesdropping and data interception. How does it work? At its core, Secure Full Duplex ISAC operates on a full duplex protocol, meaning it can simultaneously transmit and receive signals on the same frequency. This is a significant leap from traditional half-duplex systems, which can only do one at a time. By integrating sensing capabilities into this duplex system, ISAC not only facilitates communication but also gathers critical environmental data, enhancing the overall efficiency and functionality of the network. https://twitter.com/drahmadbazzi/status/1628849453317648386?embedable=true The innovation doesn't stop there. To counteract potential eavesdroppers, Secure Full Duplex ISAC employs advanced beamforming techniques and artificial noise generation. These strategies are ingeniously designed to illuminate radar beams towards potential threats, thereby sensing their presence while obscuring the communication signals from unauthorized interception. This dual approach of communication and sensing, fortified with robust security measures, sets a new benchmark for wireless communication systems. https://www.linkedin.com/feed/update/urn:li:activity:7142776580786892803?updateEntityUrn=urn%3Ali%3Afs_feedUpdate%3A(V2%2Curn%3Ali%3Aactivity%3A7142776580786892803)&embedable=true What does that mean ? The implications of Secure Full Duplex ISAC for the future of telecommunications are profound. Imagine autonomous vehicles that not only communicate with each other to prevent accidents but also sense their surroundings to navigate more efficiently. Picture smart cities where public infrastructure communicates seamlessly, sensing environmental changes and enhancing public safety in real-time. Moreover, the security benefits of Secure Full Duplex ISAC cannot be overstated. In an age where data breaches and cybersecurity threats loom large, the ability to secure wireless communications against eavesdroppers is invaluable. This technology promises a future where our communications are not only faster and more reliable but also significantly more secure. Cryptographic approaches do offer a certain level of security in the network, however, the rapid developments made in computing power devices show that even the most mathematically complex secret key-based techniques can be broken, especially when quantum computing becomes a reality [8]. Therefore, an extra level of security should rely on physical layer design, without the need for secret-key exchange, to maintain secure transmissions especially when both SAC information are revealed to malicious users. Navigating the evolution of wireless communication presents a blend of hurdles and prospects. At the heart of this evolution, Secure Full Duplex Integrated Sensing and Communications emerges as a pivotal force, signaling a shift towards a realm that's increasingly interconnected, insightful, and critically, more safeguarded. On the cusp of embracing 6G technology, it's imperative that future designs prioritize the secure integration of ISAC. This approach doesn't merely hold promise; it heralds a transformative potential that's beyond measure. In an era where the digital and physical worlds are becoming increasingly intertwined, the next wave of wireless communication technology— 6G —promises to blur these boundaries even further. But how on earth do we deal with eavesdroppers? One of the advancements on this frontier is the development of Secure Full Duplex Integrated Sensing and Communications (ISAC), a technology designed to not only enhance communication capabilities but also to provide robust security measures against eavesdropping threats. 6G But how on earth do we deal with eavesdroppers? As we venture into the possibilities of 6G, the concept of ISAC emerges as a beacon of innovation. ISAC envisions a future where communication systems are not merely passive transmitters of data but active sensors of their environment. This integration promises to open a plethora of applications, from autonomous driving to advanced remote healthcare, by leveraging the dual functionality of sensing and communication. However, with great power comes great vulnerability. The open nature of wireless communication systems makes them susceptible to eavesdropping and data interception. How does it work? How does it work? At its core, Secure Full Duplex ISAC operates on a full duplex protocol, meaning it can simultaneously transmit and receive signals on the same frequency. This is a significant leap from traditional half-duplex systems, which can only do one at a time. By integrating sensing capabilities into this duplex system, ISAC not only facilitates communication but also gathers critical environmental data, enhancing the overall efficiency and functionality of the network. https://twitter.com/drahmadbazzi/status/1628849453317648386?embedable=true https://twitter.com/drahmadbazzi/status/1628849453317648386?embedable=true The innovation doesn't stop there. To counteract potential eavesdroppers, Secure Full Duplex ISAC employs advanced beamforming techniques and artificial noise generation. These strategies are ingeniously designed to illuminate radar beams towards potential threats, thereby sensing their presence while obscuring the communication signals from unauthorized interception. This dual approach of communication and sensing, fortified with robust security measures, sets a new benchmark for wireless communication systems. https://www.linkedin.com/feed/update/urn:li:activity:7142776580786892803?updateEntityUrn=urn%3Ali%3Afs_feedUpdate%3A(V2%2Curn%3Ali%3Aactivity%3A7142776580786892803)&embedable=true https://www.linkedin.com/feed/update/urn:li:activity:7142776580786892803?updateEntityUrn=urn%3Ali%3Afs_feedUpdate%3A(V2%2Curn%3Ali%3Aactivity%3A7142776580786892803)&embedable=true What does that mean ? The implications of Secure Full Duplex ISAC for the future of telecommunications are profound. Imagine autonomous vehicles that not only communicate with each other to prevent accidents but also sense their surroundings to navigate more efficiently. Picture smart cities where public infrastructure communicates seamlessly, sensing environmental changes and enhancing public safety in real-time. Moreover, the security benefits of Secure Full Duplex ISAC cannot be overstated. In an age where data breaches and cybersecurity threats loom large, the ability to secure wireless communications against eavesdroppers is invaluable. This technology promises a future where our communications are not only faster and more reliable but also significantly more secure. Cryptographic approaches do offer a certain level of security in the network, however, the rapid developments made in computing power devices show that even the most mathematically complex secret key-based techniques can be broken, especially when quantum computing becomes a reality [8]. Therefore, an extra level of security should rely on physical layer design, without the need for secret-key exchange, to maintain secure transmissions especially when both SAC information are revealed to malicious users. Cryptographic approaches do offer a certain level of security in the network, however, the rapid developments made in computing power devices show that even the most mathematically complex secret key-based techniques can be broken, especially when quantum computing becomes a reality [8]. Therefore, an extra level of security should rely on physical layer design, without the need for secret-key exchange, to maintain secure transmissions especially when both SAC information are revealed to malicious users. Navigating the evolution of wireless communication presents a blend of hurdles and prospects. At the heart of this evolution, Secure Full Duplex Integrated Sensing and Communications emerges as a pivotal force, signaling a shift towards a realm that's increasingly interconnected, insightful, and critically, more safeguarded. On the cusp of embracing 6G technology, it's imperative that future designs prioritize the secure integration of ISAC. This approach doesn't merely hold promise; it heralds a transformative potential that's beyond measure.

Securing the Future: The Impact of Full Duplex ISAC in the 6G Era

Welcome to the Startups of the Year Winner Interview Series. Congratulations for being one of the top 3000 startups worldwide! The HackerNoon team is thrilled to know more about you! What follows is an interview with Mark Zalan, CEO of GoMining, winner of the HackerNoon Startups of the Year 2023 in the British Virgin Islands Misc, Oceania. What does it mean for you to win this title? We are pleased and gratified at the recognition of our contributions. We are constantly looking for community feedback to improve our products, and this kind of appreciation helps make our efforts worthwhile. Winning the Hackernoon community recognition is a significant indicator for us that our team is moving in the right direction. Since our product targets a fairly broad audience, the trust of the audience and feedback help us better understand user needs, and Hackernoon provides the perfect environment for addressing this task. What sets you apart from the competition? We are focused on making the superior economics of Bitcoin mining accessible to everyone.  In building products that allow our users to start mining Bitcoin within a matter of minutes and at a cost as low as $25, we are unique. The explosive customer demand we’ve seen over the past 2 years is a confirmation of that. Check out our What do you love about your team, and why are you the ones to solve this problem? \We are irreverent around challenging every assumption and traditional way of doing things.  Obviously, this can be a strength and a weakness, and if not done right, can lead to reinventing the wheel.  However, we’ve managed to maintain a healthy balance between blazing new trails and inventing a new product (that hundreds of people told us couldn’t be done), making the economics of Bitcoin mining accessible to non-industry insiders and leveraging traditional approaches that we’ve confirmed are useful in what we are trying to do. This blend of questioning the way things are and inventing new and better ways while staying practical and leveraging that which works for purpose has allowed us to offer a successful product that is posting world-class growth rates. If you weren’t building your startup, what would you be doing? My other passions are history and political science, as well as understanding how our societies function and evolved to where we are today.  In another life I would likely be lecturing at a university and writing history books. At the moment, how do you measure success? What are your core metrics? We are seeing double-digit monthly growth rates while working hard to expand the business that is profitable, positioned in the middle of an industry that is projected for staggering worldwide growth.  All of the above are how we think about success and how we want to position our ecosystem to take advantage of the global and industry trends we see for the near future.  If I had to narrow it down to one metric, it is definitely the customer growth rate, which tells us we are tackling a significant pain-point that exists for a large number of people, in a way they appreciate. Tell us how your startup is changing the world. We make the excellent economics of Bitcoin mining available to regular people. Getting a financial return with Bitcoin mining traditionally required millions of dollars in capital and highly specialized technical skills (that also cost money to develop or hire).  We’ve built a product that obfuscates that complexity and allows customers to start participating in Bitcoin mining in minutes and with as little as $25, with the first profit landing in the customer’s Bitcoin wallet the very next morning.  By lowering the barriers to entry for normal people to earn rewards, while strengthening, securing the Bitcoin network infrastructure, we make our positive impact on the world. How do you or your company intend to embrace the responsibility of this title in 2024? We believe the best way to contribute and to give back is to do what we do best, continue to innovate, while lowering barriers to entry, and to be a good citizen of the Bitcoin and broader technology community. The recognition from users and the community serves as a driving force for our continued advancement and, as I mentioned earlier, provides vital feedback on the quality of our product. What goals are you looking forward to accomplishing in 2024? We expect 2024 to be transformational for us through a variety of factors. Firstly, the Bitcoin halving will impact our business and our vertical in a significant way.  The economics will change, and the market participants will change. We’ve been preparing for this event for the past three years ensuring our business is cost optimized and as efficient as possible, as we expect this will allow us and our user community to pass through the upcoming disruption, and to be best positioned to take advantage of the changing economics following the halving.  Secondly, our user community is scaling by orders of magnitude, and we place a major focus on ensuring our support and engagement processes are peerless in creating a world-class user experience. Which trend(s) are you most excited about in 2024? Share your reasons. 2024 Is a paradigm-shifting year for the Bitcoin mining community with the ETFs and the halving taking place within three months of each other.  We are very excited to see the ways in which our industry and the broader technology space will transform to take advantage of the changes. 2023 had been another crazy year, especially in tech, with layoffs and the Generative AI takeover! Which trend are you most concerned about? Be as brief or as detailed as you like. I wouldn’t say concerned, but we are very cognizant of the pace of change. It seems things are speeding up, paradigms are shifting quickly, changes that used to take decades now take years or sometimes months. The way the world became location-independent in the past four years is very illustrative of that. We expect changes of the same scale to happen as quickly or faster going forward, so it will be important to be diligent in always learning, looking for ways to do something better, and being flexible, adjusting to take advantage of new trends, technologies, and opportunities. We don’t know what specifically those will be, five years ago, hardly anyone would have said that remote work, generative AI or Bitcoin ETFs/general institutionalization would be a thing over the next 5 years, so we don’t think it's worthwhile to predict specifics. We do think it's important to understand that changes happen quickly. They bring threats and opportunities, and figuring it out is a fun and exciting part of it. Share your biggest success so far and/or your biggest failure so far. Building a career out of always learning, developing, and pushing myself into new pursuits, taking advantage of opportunities that may have scared others off, is probably the biggest success. In terms of failure, I certainly wish I was smarter along the way, and figured out many things faster than I did! :) We would love your feedback on HackerNoon as a tech publication! How has your experience been with us? HackerNoon is an excellent platform for showcasing our technological solutions to a wide and relevant community capable of providing objective feedback. We closely monitor all materials about our product appearing on Hackernoon and pay attention to UX moments that require improvement. In a broader sense, your platform is a great place to feel the pulse of Web3, track emerging trends, and receive important insights directly from where they originate. Any words of wisdom you’d like to share with us? Not wildly original here, but the advice I most want to pass on to my children is to enjoy the journey, whatever destination one travels. This is one of the things I wish I would have figured out sooner. Welcome to the Startups of the Year Winner Interview Series. Congratulations for being one of the top 3000 startups worldwide! The HackerNoon team is thrilled to know more about you! Welcome to the Startups of the Year Winner Interview Series. Congratulations for being one of the top 3000 startups worldwide! The HackerNoon team is thrilled to know more about you! Welcome to the Startups of the Year Winner Interview Series. Congratulations for being one of the top 3000 startups worldwide! The HackerNoon team is thrilled to know more about you! What follows is an interview with Mark Zalan, CEO of GoMining, winner of the HackerNoon Startups of the Year 2023 in the British Virgin Islands Misc, Oceania. What follows is an interview with Mark Zalan, CEO of GoMining , winner of the HackerNoon Startups of the Year 2023 in the British Virgin Islands Misc, Oceania . GoMining British Virgin Islands Misc, Oceania What does it mean for you to win this title? What does it mean for you to win this title? We are pleased and gratified at the recognition of our contributions. We are constantly looking for community feedback to improve our products, and this kind of appreciation helps make our efforts worthwhile. Winning the Hackernoon community recognition is a significant indicator for us that our team is moving in the right direction. Since our product targets a fairly broad audience, the trust of the audience and feedback help us better understand user needs, and Hackernoon provides the perfect environment for addressing this task. What sets you apart from the competition? We are focused on making the superior economics of Bitcoin mining accessible to everyone.  In building products that allow our users to start mining Bitcoin within a matter of minutes and at a cost as low as $25, we are unique. The explosive customer demand we’ve seen over the past 2 years is a confirmation of that. Check out our What do you love about your team, and why are you the ones to solve this problem? \We are irreverent around challenging every assumption and traditional way of doing things.  Obviously, this can be a strength and a weakness, and if not done right, can lead to reinventing the wheel.  However, we’ve managed to maintain a healthy balance between blazing new trails and inventing a new product (that hundreds of people told us couldn’t be done), making the economics of Bitcoin mining accessible to non-industry insiders and leveraging traditional approaches that we’ve confirmed are useful in what we are trying to do. This blend of questioning the way things are and inventing new and better ways while staying practical and leveraging that which works for purpose has allowed us to offer a successful product that is posting world-class growth rates. If you weren’t building your startup, what would you be doing? My other passions are history and political science, as well as understanding how our societies function and evolved to where we are today.  In another life I would likely be lecturing at a university and writing history books. At the moment, how do you measure success? What are your core metrics? We are seeing double-digit monthly growth rates while working hard to expand the business that is profitable, positioned in the middle of an industry that is projected for staggering worldwide growth.  All of the above are how we think about success and how we want to position our ecosystem to take advantage of the global and industry trends we see for the near future.  If I had to narrow it down to one metric, it is definitely the customer growth rate, which tells us we are tackling a significant pain-point that exists for a large number of people, in a way they appreciate. Tell us how your startup is changing the world. We make the excellent economics of Bitcoin mining available to regular people. Getting a financial return with Bitcoin mining traditionally required millions of dollars in capital and highly specialized technical skills (that also cost money to develop or hire).  We’ve built a product that obfuscates that complexity and allows customers to start participating in Bitcoin mining in minutes and with as little as $25, with the first profit landing in the customer’s Bitcoin wallet the very next morning.  By lowering the barriers to entry for normal people to earn rewards, while strengthening, securing the Bitcoin network infrastructure, we make our positive impact on the world. How do you or your company intend to embrace the responsibility of this title in 2024? We believe the best way to contribute and to give back is to do what we do best, continue to innovate, while lowering barriers to entry, and to be a good citizen of the Bitcoin and broader technology community. The recognition from users and the community serves as a driving force for our continued advancement and, as I mentioned earlier, provides vital feedback on the quality of our product. What goals are you looking forward to accomplishing in 2024? We expect 2024 to be transformational for us through a variety of factors. Firstly, the Bitcoin halving will impact our business and our vertical in a significant way.  The economics will change, and the market participants will change. We’ve been preparing for this event for the past three years ensuring our business is cost optimized and as efficient as possible, as we expect this will allow us and our user community to pass through the upcoming disruption, and to be best positioned to take advantage of the changing economics following the halving.  Secondly, our user community is scaling by orders of magnitude, and we place a major focus on ensuring our support and engagement processes are peerless in creating a world-class user experience. Which trend(s) are you most excited about in 2024? Share your reasons. 2024 Is a paradigm-shifting year for the Bitcoin mining community with the ETFs and the halving taking place within three months of each other.  We are very excited to see the ways in which our industry and the broader technology space will transform to take advantage of the changes. 2023 had been another crazy year, especially in tech, with layoffs and the Generative AI takeover! Which trend are you most concerned about? Be as brief or as detailed as you like. I wouldn’t say concerned, but we are very cognizant of the pace of change. It seems things are speeding up, paradigms are shifting quickly, changes that used to take decades now take years or sometimes months. The way the world became location-independent in the past four years is very illustrative of that. We expect changes of the same scale to happen as quickly or faster going forward, so it will be important to be diligent in always learning, looking for ways to do something better, and being flexible, adjusting to take advantage of new trends, technologies, and opportunities. We don’t know what specifically those will be, five years ago, hardly anyone would have said that remote work, generative AI or Bitcoin ETFs/general institutionalization would be a thing over the next 5 years, so we don’t think it's worthwhile to predict specifics. We do think it's important to understand that changes happen quickly. They bring threats and opportunities, and figuring it out is a fun and exciting part of it. Share your biggest success so far and/or your biggest failure so far. Building a career out of always learning, developing, and pushing myself into new pursuits, taking advantage of opportunities that may have scared others off, is probably the biggest success. In terms of failure, I certainly wish I was smarter along the way, and figured out many things faster than I did! :) We would love your feedback on HackerNoon as a tech publication! How has your experience been with us? HackerNoon is an excellent platform for showcasing our technological solutions to a wide and relevant community capable of providing objective feedback. We closely monitor all materials about our product appearing on Hackernoon and pay attention to UX moments that require improvement. In a broader sense, your platform is a great place to feel the pulse of Web3, track emerging trends, and receive important insights directly from where they originate. Any words of wisdom you’d like to share with us? Not wildly original here, but the advice I most want to pass on to my children is to enjoy the journey, whatever destination one travels. This is one of the things I wish I would have figured out sooner.

Meet GoMining: Winner of the Startups of the Year, British Virgin Islands 

Authors: (1) Gopal Yadav, Department of Physics, Indian Institute of Technology & Chennai Mathematical Institute. Table of Links Abstract Acknowledgment PART I Chapter 1: Introduction Chapter 2: SU(3) LECs from Type IIA String Theory Chapter 3: Deconfinement Phase Transition in Thermal QCD-Like Theories at Intermediate Coupling in the Absence and Presence of Rotation Chapter 4: Conclusion and Future Outlook PART II Chapter 5: Introduction Chapter 6: Page Curves of Reissner-Nordström Black Hole in HD Gravity Chapter 7: Entanglement Entropy and Page Curve from the M-Theory Dual of Thermal QCD Above Tc at Intermediate Coupling Chapter 8: Black Hole Islands in Multi-Event Horizon Space-Times Chapter 9: Multiverse in Karch-Randall Braneworld Chapter 10: Conclusion and Future outlook APPENDIX A APPENDIX B APPENDIX C Bibliography CHAPTER 8 - BLACK HOLE ISLANDS IN MULTI-EVENT HORIZON SPACE-TIMES 8.1 Introduction and Motivation The information paradox of black holes has been investigated for black holes that are asymptotically flat, however the most recent observation indicates that our universe is currently in an accelerated phase. Because of this, it is only natural to wonder how the presence of a positive value for the cosmological constant Λ influences the information paradox problem. The information paradox of a stationary black hole with a positive cosmological constant Λ or the Schwarzschild de-Sitter black hole spacetime is something that attracted our attention. The information paradox of Schwarzschild de-Sitter black holes is important due to the fact that these black holes originated during the early inflationary phase of our universe (for example, [210–213]). It additionally offers a fantastic toy model for the global framework of isolated black holes of our universe, which is quite useful while keeping in mind the current period of accelerated expansion. Additionally, similar to the situation with black holes, there are regions of de Sitter space that are causally separated from one another. Therefore, an observer is only able to access the portions of the cosmos that are constrained by their own horizon. There are two event horizons associated with the Schwarzschild de-Sitter black hole: the cosmological event horizon (CEH) and the black hole event horizon (BEH). The global causal border of the de Sitter spacetimes has been provided by the cosmological event horizon. In comparison to Λ ≤ 0 single horizon spacetime, the thermodynamics of these event horizons are distinct [214–216]. Gibbons-Hawking radiation is emitted and absorbed by cosmological event horizon similar to the Hawking radiation of black holes. Comparatively speaking, the entropy creation of the cosmic horizon is an observer-dependent characteristic, in contrast to the entropy generation of the black hole. It is caused by people’s lack of knowledge regarding the things that exist beyond the cosmological horizon. In order to obtain the Page curve of the Schwarzschild de-Sitter black hole, we make use of the island concept. In the case of models that are not holographic, we are able to use the s-wave approximation for studying black holes in higher dimensions. Because we neglect the angular component of the metric when performing the s-wave approximation, we are left with a CFT metric that only has two dimensions. Because of this, we are able to compute the entanglement entropy of Hawking radiation using the formula for 2D CFT that is provided in [192, 193]. The entanglement entropy and complexity have been studied in [217–219] in the context of de-Sitter space. The purpose of this work was to investigate the information paradox and its resolution of black holes with multiple horizons. We considered the Schwarzschild de-Sitter black hole with two horizons and obtained the Page curves for the black hole and the de-Sitter patches by placing thermally opaque membranes on the two sides of the region of study. The “effect of temperature” on the Page curves and the scrambling time is something else that would be of interest to us. In this chapter, we will discuss the Page curve of black hole patch only. 8.2 Preliminary In this section, we will discuss the basics of Schwarzschild de-Sitter black hole, the concept of thermal opaque membrane and the effect of gravity near the aforementioned membrane in 8.2.1, 8.2.2, and 8.2.3 respectively. 8.2.1 Schwarzschild de-Sitter Black Hole The Schwarzschild de-Sitter (SdS) metric has the following form in spherical polar coordinates: and, where the Kruskal coordinates are: Therefore (8.7) and (8.8) do not have any coordinate singularities at r = rH and r = rC. It is not possible to remove the coordinate singularities of both event horizons simultaneously. Hence, we have to study the black hole patch by freezing the de-Sitter patch using thermal opaque membrane and vice-versa. 8.2.2 Thermal Opaque Membranes in SdS Space-Time The fact that the effective potential term disappears at both horizons and remains positive in between them is something that stands out as an interesting feature of the Schrödingerlike equation that was given before. Therefore, this bell-shaped potential acts as a barrier between the event horizons of the black hole and de-Sitter space. To be able to depict it in Penrose diagram of the extended Schwarzschild de-Sitter space-time, we will use (8.9) to describe the Kruskal timelike and spacelike coordinates as follows: implying Therefore, the line r =constant is a hyperbola linking i ±, and it is possible to draw it with regard to any of the Kruskal coordinates listed above. This appears in the Penrose diagram of the maximally extended SdS space-time. When we have put this hyperbola or the thermal opaque membrane, modes on each side of wall will be unable to pass through it and will continue to exist in their respective regions. A natural manifestation of this effective potential could be possible with the thermally opaque membrane. 8.2.3 Bulk Gravitational Effect Near Thermal Opaque Membranes In the context of this discussion, we are interested in the bulk gravitational influence on thermally opaque membranes. Using the island formula, the authors of [229, 230] studied the information paradox of pure de-Sitter space, evaporating and eternal black holes in the weak gravity domain. These setups do not include an exterior bath and the authors included an anchor curve that produces both an interior and an exterior. The island formula can be applied despite the fact that gravity is extremely weak on the exterior region. We suggest that we may think of an “anchor curve” going through the locations b ± 1,2 within our setup also where we have specified the boundaries of radiation regions in Figs. 8.1 and 8.2. Our justification is based on [229,230]. The interior and exterior in our setup are marked by these “anchor curves”. The “thermal opaque membrane” is being able of blocking the radiation coming from the region, that is not relevant to our research in any way. Therefore, the applicability of the island formula to our situation can only be considered notional at this point. The information paradox that arises from black holes in multi-event horizon spacetime can be solved using this approach. Considering the membrane that was discussed before is located at a significant distance from the region affected by the black hole, it is reasonable to suppose that the gravitational effects around these membranes is insufficiently strong. As a result, 2 CFT formulas can be utilized to determine the entanglement entropy of Hawking radiation. We have discussed another approach to get the Page curve of Schwarzschild deSitter black hole in chapter 9 using wedge holography. D 8.3 Black Hole Islands in Schwarzschild de-Sitter Black Hole The conformal factor and Kruskal coordinates, both of which exist in (8.13), are defined as follows: It has been calculated that thermal entropy of the black hole is: 8.3.1 No Island Phase In this case, the region of interest for the black hole patch is the area that is completely encompassed by the thermally opaque membrane on both sides in the C and L domains. Without island surface, we were able to calculate the entanglement entropy of Hawking radiation by utilizing the two-dimensional CFT formula that is given below [192, 193]: By utilizing (8.14), (8.5) and (8.17), we are able to simplify the equation (8.16). The form in its refined version is written as follows: The above equation has a significant physical meaning that it predicts that there is going to be a limitless quantity of Hawking radiation due to its linear time dependence upon entanglement entropy. This is in contrast to the fact that the Page curve of an eternal black hole predicts that there will only be a finite amount of Hawking radiation [132]. 8.3.2 Island Phase Taking into account the island surface as part of the setup, we will now calculate the entanglement entropy of Hawking radiation. With inclusion of the island surface, the entanglement entropy of the Hawking radiation can be determined using the formula [192, 193], which is the matter component of the generalized entropy (5.11). Simplifying the expression for the matter contribution to the generalized entropy (5.11) from the radiation and island regions by utilizing (8.13), and (8.17). We obtained: As a result, the area of the boundary of the island surface and the matter component (8.22) are added together to generate the generalized entropy (5.11): The previous equation has the following solution: Using the above equation, we can determine that the island exists at the following location: Since the second component in the above equation has a negative sign in front of it, the island must be found inside the black hole horizon. We have showed in the Penrose diagram where islands are beyond the black hole event horizon, but we have found that it lies within the horizon itself. Substituting a1 from (8.28) into the definition of generalized entropy yields: Because of this, we may deduce that the entanglement entropy of Hawking radiation remains constant when the island is incorporated into the black hole’s interior and is thus equal to twice the black hole’s thermal entropy (to leading order in G ). N Hawking radiation’s entanglement entropy without the island surface is equivalent to its entanglement entropy with the island surface present at a point in time called “Page time” as discussed in chapter 6. By equating (8.19) and (8.29), we obtained the Page time as given below: Page time: : The scrambling time is discussed in detail in chapter 6. For the black hole patch in Schwarzschild de-Sitter black hole, scrambling time can be obtained using the following equation: Scrambling time From (8.5) and (8.28), the black hole patch’s scrambling time is therefore obtained as: 8.3.3 Page Curves The black hole patch Page curves are now obtained using the results of 8.3.1 and 8.3.2. (8.19) and (8.29) are the key equations. When we incorporate the island surface, the entanglement entropy of Hawking radiation changes from a time-dependent function of entanglement entropy to a constant value of (2S BEH th ) (8.29). As a result, if we plot all of these contributions together, we get the Page curves of eternal black holes that are in accord with their unitary evolution. From the use of (8.2), (8.3), (8.19) and (8.29), we obtained the Page curves for black hole patch when Q = GN = 1, 3M √ Λ = 0.4 (green) and 3M √ Λ = 0.5 (magenta), shown in Fig. 8.3. As the mass of the black hole grows (as shown in 8.3), the Page curves move later in time. As a result, information recovered from large black holes takes much more time than that from smaller black holes. This finding can also be interpreted in terms of the temperature of black holes. Information can be recovered faster from black holes with higher temperatures than from those with lower temperatures because the black hole temperature is inversely related to black hole mass. To rephrase, island emerges earlier for the black holes with higher temperatures compared to the black holes with lower temperature. 8.4 Information Problem in SdS Black Hole as a Whole 8.5 Conclusion Using the Island concept, we have investigated the information paradox that is associated with the black hole patch in the Schwarzschild-deSitter black hole spacetime. On both sides of the black hole patch, we used thermally opaque membranes to create an isolation barrier between the black hole and the de-Sitter patches, and vice versa. We calculated the entanglement entropy of Hawking radiation without and with the inclusion of an island surface and found that, as is typical, the entanglement entropy has a linear time dependency as long as there isn’t an island surface, but it turns into constant value when there is an island surface present. As a result, we are able to produce the Page curve in a manner that accords with the unitary evolution of the black holes. In this particular instance, the island can be found inside the horizon of the black hole, in contrast to the universal finding, which states that the island must be found outside the horizon of the black hole in the case of eternal black holes [197]. Our results are likewise comparable to those presented in [235], in which the researchers calculated the Page curve of a one-sided asymptotically flat black hole and found that the island lies within the horizon of the black hole. In addition, we have investigated the “effect of temperature” on the Page curves depicted by the black hole patch. We noticed that as the temperature of the black hole patch rose, a shift toward later times occurred in the Page curves. When compared to the black hole patch with the greater temperature, the one with the lower temperature will take a significantly longer amount of time to send the information to the observer. This suggests that the island of the black hole patch doesn’t make its appearance until much later for the black hole patch with the lower temperature, but the island makes its debut much sooner for the black hole patch with the higher temperature. We are able to begin the process of recovering the information that was flung into the black holes horizon as soon as an island surface enters into the picture [194, 195]. As a result, we get to the conclusion that the temperature of both event horizons has a role in determining the “dominance of islands” and the “scrambling time”. This paper is under CC 4.0 license. available on arxiv

Black Hole Islands in Multi-Event Horizon Space-Times

The Noonification: Gravity Islands and the Multiverse (2/22/2024)

Authors: (1) Gopal Yadav, Department of Physics, Indian Institute of Technology & Chennai Mathematical Institute. Table of Links Abstract Acknowledgment PART I Chapter 1: Introduction Chapter 2: SU(3) LECs from Type IIA String Theory Chapter 3: Deconfinement Phase Transition in Thermal QCD-Like Theories at Intermediate Coupling in the Absence and Presence of Rotation Chapter 4: Conclusion and Future Outlook PART II Chapter 5: Introduction Chapter 6: Page Curves of Reissner-Nordström Black Hole in HD Gravity Chapter 7: Entanglement Entropy and Page Curve from the M-Theory Dual of Thermal QCD Above Tc at Intermediate Coupling Chapter 8: Black Hole Islands in Multi-Event Horizon Space-Times Chapter 9: Multiverse in Karch-Randall Braneworld Chapter 10: Conclusion and Future outlook APPENDIX A APPENDIX B APPENDIX C Bibliography Part-II (HD) Gravity Islands, and Multiverse “God does not play dice.” - Albert Einstein “God not only plays dice, he sometimes throws the dice where they cannot be seen.” - Stephen Hawking “If God throws dice where they cannot be seen, they cannot affect us.” - Don Page CHAPTER 5 - INTRODUCTION In this chapter, we present the introduction of the materials needed to understand the information paradox and its resolution from holography. We start with the discussion on entanglement entropy in section 5.1, we discuss the information paradox and the Page curve in section 5.2 and finally we discuss the resolution of the information paradox in 5.3 from the island proposal, doubly holographic setup and wedge holography in 5.3.1, 5.3.2 and 5.3.3 respectively 5.1 Holographic Entanglement Entropy: Ryu-Takayanagi and Dong’s Proposals Let us first discuss the entanglement entropy in quantum mechanical system. Let us consider a system whose state is denoted by |ψ⟩. The density matrix of the system is defined as: Entanglement Entropy in Quantum Mechanics (QM): Entanglement entropy is measured by the von-Neumann entropy. For this, first we have to partition the system into two subsystems A and B. States in the subsystems A and B are denoted by |ψ⟩A and |ψ⟩B such that |ψ⟩ = |ψ⟩AB = |ψ⟩A ⊗ |ψ⟩B . Reduced density matrix of the subsystem A is obtained by tracing over the degrees of freedom of the subsystem B and vice-versa. Now, the von-Neumann entropy is defined as: It is not easy to compute the entanglement entropy in quantum field theories (QFTs) by factoring the system into subsystems because factorization is not always possible in QFTs. Entanglement entropy in QFT is calculated using the replica trick. First, let us define the Renyi entropy: Entanglement Entropy in Quantum Field Theory (QFT): • We need to find out a co-dimension two surface (ϵA) in the bulk Md+1 which is anchored on ∂A. • There is possibility of many surfaces but we have to consider the one which satisfy the homology constraint, i.e., ϵA is smoothly retractable to the boundary region A. • Out of those surfaces which satisfy homology constraint, we need to pick the one with the minimal area then the entanglement entropy is defined as: The Ryu-Takayangi formula has certain limitation, it is applicable to the the timeindependent backgrounds. For the time dependent background, one is required to use the HRT formula [125] where HRT stands for Hubney, Rangamani and Takayanagi. Quantum corrections to all order in ℏ to the Ryu-Takayanagi formula was incorporated in [126] where one is required to extremize the generalised entropy. Surfaces which extremize the generalised entropy are known as quantum extremal surfaces(QES). If there are more than one quantum extremal surfaces then we need to consider the one with minimal area. In [6], authors generalised the QES prescription to island surfaces where we are required to extremize the generalised entropy like functional which includes contribution from the island surfaces. In this case, extremal surfaces are known as quantum extremal islands. Since, in this thesis, we are confining ourselves to the time independent backgrounds and therefore we will not discuss the HRT formula. • Let us label the each term as αth term after getting the final expression of the second term which is obtained from the differentiation of Lagrangian with respect to Riemann tensor twice. • We need to perform the following transformations on certain components of the Riemann tensors: The reason for discussing these proposals is that when we compute the Page curve of black holes in doubly holographic setup and wedge holography then these proposals will be useful. The holographic entanglement entropy has also been computed from the holographic stress tensor and surface terms in [128] and [129] respectively. 5.2 Hawking’s Information Paradox and Page Curve Hawking’s black hole information paradox is a long-time puzzle that started with his papers [130, 131]. When matter collapses to form a black hole, the whole matter is stored in the singularity. The horizon of the black hole covers the black hole singularity. Initially, the system is in a pure state. Hawking studied the creation of particles in pairs with negative and positive energy in the presence of quantum effects, and he found that a particle with negative energy gets trapped inside the black hole, whereas the particle with positive energy scattered off to infinity is what we receive in Hawking radiation. We can get the radiation from the black hole due to quantum mechanics, which allows the possibility of quantum tunneling through a potential barrier. In the case of a black hole, the horizon acts as the potential barrier. Hawking calculated the spectrum of the particles coming out of the black hole and found that the spectrum behaves as the spectrum of thermal radiation with a temperature known as Hawking temperature, which implies a mixed state. This means that the black hole evolves from the pure state to the mixed state, and hence unitary evolution of quantum mechanics is not preserved. This leads to the famous “information paradox”. Page suggested that when we include the quantum effects, then the black hole must follow the unitary evolution [132]. If we consider the black hole and radiation region as a single system, then one should get the Page curve to resolve the paradox. For the evaporating black hole, entanglement entropy of the Hawking radiation first increases linearly with time up to the Page time and then falls back to zero [132]. We are interested in eternal black holes, and for these black hoes, instead of falling to zero of the entanglement entropy, one obtains the constant entanglement entropy after the Page time, and this constant value is equal to the twice the thermal entropy of the black holes. In this part of the thesis, we focus on getting the Page curve of eternal black holes using the recent proposals given in the literature, e.g., island proposal, doubly holographic setup, and wedge holography. Apart from getting the Page curve, we have also obtained other exciting results, which are discussed in the upcoming chapters. 5.3 Resolution of Information Paradox from Holography Following three proposals are available in the literature which started with the idea of holography to resolve the black hole information paradox. 5.3.1 Island Proposal and its Extension to HD Gravity Authors in [6] proposed a method to resolve the information paradox which is equivalent to getting the Page curve. Idea is that at early times we get only contribution from the radiation region which gives the divergent part of entanglement entropy at late times because the entanglement entropy of Hawking radiation turns out to be proportional to the time. According to [6] at early times situation remains the same whereas at late times interior of the black holes becomes part of the entanglement wedge and hence at late times entanglement entropy receives the contributions from the radiation as well as interior of the black holes. The part of the interior the black holes which contributes to the entanglement entropy is known as “island”. Island rule was proposed from a setup where we couple the evaporating JT(Jackiw Teitelboim) black hole plus conformal matter on the Planck brane with the two-dimensional CFT bath [6]. The black hole is contained on the Planck brane, and the Hawking radiation is collected in the 2D conformal bath. This setup has the following three descriptions. The Planck brane is coupled to the external CFT bath, which acts as the sink for the Hawking radiation. • 2D-Gravity: Two-dimensional conformal field theory has the three-dimensional gravity dual with metric AdS3 via AdS/CFT correspondence. • 3D-Gravity: The boundary of the external CFT bath is one dimensional where quantum mechanics (QM) is present. • QM: The island formula was derived from the gravitational path integral using the replica trick for special JT black holes in [133, 134]. The authors obtained the Page curve from the disconnected and connected saddles. One obtains the linear time dependence in the Page curve from the disconnected saddles, whereas connected saddles produce the finite part of the Page curve. The discussion of [133] holds for the replica wormholes with boundary as well. The generalised entropy in the presence of island surface is written as follows: n where R, GN and I are representing the radiation region, Newton constant and the island surface. Equation (5.11) contains two terms: island surface’s area and the matter contribution from the radiation and island regions. From (5.11), we can easily see that when island surface is absent then S (r) = S r(R). It has been shown in the literature that island surface emerges at late times and hence initially one obtains the linear time dependence in the Page curve and at late times, when island surface’s contribution dominates then one obtains the fall of the entanglement entropy for the evaporating black holes whereas constant part (twice of their thermal entropies) for the eternal black holes. Hence, when we include these contributions, we obtain the Page curve. If there are more than one island surfaces then we have to consider the one with the minimal area. We have followed this proposal to obtain the Page curve of Schwarzschild de-Sitter black hole in [12] and discussed in detail in the chapter 8 of this thesis. See [135–137] for the application of island proposal in the context of JT gravity and other issues [138–140]. gen matte Island proposal was extended for higher derivative gravity in [141]. The proposal is exactly similar to [6] but we have to replace the first term of (5.11) by the term which can give the information about the entanglement entropy of higher derivative gravity and the formula for the same was proposed by X. Dong in [127] and hence the island proposal in the presence of higher derivative terms in the gravitational action is written as [141] where Smatter is the same as the S (R ∪ I) of (5.11) and S will be calculated using the Dong’s formula [127]. For the AdSd+1/CF Td correspondence the Dong’s formulas is given below[1]. matter gravity where 5.3.2 Doubly Holographic Setup The doubly holographic setup is a nice setup to calculate the Page curve of black holes. As its name suggests, it is the double copy of the usual holography proposed by J. Maldacena. First, we need to take the bulk and truncate the geometry along one of the spatial coordinates [142, 143]. By doing so, one generates d-dimensional geometry embedded in the (d + 1)- dimensional bulk. The d-dimensional geometry is known as end-of-the-world brane or KarchRandall brane in the literature, and this holography is called “braneworld holography”. The doubly holographic setup is obtained by joining the two copies of the Karch-Randall model. The setup consists of an eternal black hole living on the brane and two baths where we can collect the Hawking radiation. These two baths behave as thermofield double states because these are like two copies of the boundary conformal field theory (BCFT). Let us discuss the double holography in the context of AdS correspondence using a bottom-up approach, and the setup is shown in figure 5.1. d+1/BCFTd The doubly holographic setup has the three descriptions summarised below. -dimensional BCFT at the conformal boundary of the bulk AdS . The boundary of is the ( ) dimensional defect. • Boundary description: d d+1 BCFTd d − 1 Gravity on the end-of-the-world brane is coupled to BCFT via transparent boundary condition at the defect. • Intermediate description: The holographic dual of is spacetime. • Bulk description: BCFTd AdSd+1 The intermediate description is very crucial to resolving the information paradox. Because in this description black hole living on the end-of-the-world brane directly couples with the external CFT bath. Define S(R) as the von Neumann entropy of the subregion R on a constant time slice in description 1. One can obtain the S(R) in second description from the island rule [6]: where generalised entropy functional (S (R ∪ I)) is [126]: gen A doubly holographic setup is advantageous in the sense that we can obtain very easily using the classical Ryu-Takayanagi formula [107]. When bulk is (d + 1) dimensional then [107]: S(R) where γ is the minimal co-dimension of two surface in bulk. In figure 5.1, there are two BCFTs on the conformal boundary of the bulk. The vertical line is the end-of-the-world brane which contains the black hole. The CFT bath collects the Hawking radiation emitted by the black hole. This setup has two possible extremal surfaces: Hartman-Maldacena [144] and island surfaces. The Hartman-Maldacena surface connects the two BCFTs; it starts at the CFT bath, crosses the horizons, reaches up to the turning point, and then meets the thermofield double partner of BCFT. The entanglement entropy is divergent at late times for the Hartman-Maldacena surface, which implies Hawking’s information paradox. The island surface starts at the external CFT bath and lands on the end-of-the-world brane. The island surface’s entanglement entropy turns out to be a constant value (twice of thermal entropy of the black hole). Therefore, one recovers the Page curve by combining the contributions of the entanglement entropies of both these extremal surfaces. See [7, 145–161] for the extensive literature on the doubly holographic setup. Some authors found that gravity is massive on the end-of-the-world brane [162–165] when we couple the brane to the external CFT bath. In some papers, it was shown by the authors that we could construct the doubly holographic setup with massless gravity on the brane [11, 154, 166, 167]. We constructed the doubly holographic setup from a top-down approach in [11] and details are given in chapter 7. We have a non-conformal bath (QCD2+1) and the holographic dual is M theory inclusive of O(R4 ) corrections [1]. The reason for the existence of massless graviton in our setup is that we required the wave function of the graviton to be normalized, the second reason is due to the Dirichlet boundary condition on the wave function of the graviton, and the third reason is that end-of-the-world brane had non-zero tension and hence localization of graviton is possible on the brane in a “volcano”- like potential. We obtained the Page curve with massless gravity in our setup, which was impossible in other doubly holographic setups without the DGP term. One alternate method to deduce the massless gravity on the brane is to include the Dvali-Gabadadze-Porrati (DGP) term [168] on the brane [166].5.3.3 Wedge Holography 5.3.3 Wedge Holography In the doubly holographic setup, the external bath is a fixed CFT bath. In some of the papers, it was found that gravity is massive on the end-of-the-world brane and island prescription is not valid in the masssless gravity. Some of the authors considered the bath as gravitating too [8, 9, 162, 169]. This setup is known as wedge holography in the literature. It was also argued that in wedge holography, Hartman-Maldacena surface does not exist and hence no Page curve in wedge holography. In [13], we showed that entanglement entropy of HartmanMaldacena surface is non-zero for the AdS and Schwarzschild black hole and it is zero for the de-Sitter black hole. This implies that one could get the Page curve for the AdS and Schwarzschild black hole but not for the de-Sitter space using wedge holography. See Fig.5.2 for the pictorial description of the wedge holography. One can get the Page curve or not in wedge holography is a debatable topic. Some progress in this direction has been made in [166]. It was shown by the author that we can get the Page curve with massless gravity localize on the Karch-Randall brane provided we have to include the DGP term on the Karch-Randall brane, see [170, 171] for the detailed analysis with examples. Take into consideration the following action, [8, 9, 169], to describe the mathematical description of wedge holography: The above equation has the following solution [9]: Similar to the double holography, wedge holography has also the three descriptions: BCF Td on the conformal boundary of the bulk with the ( ) dimensional defect. • Boundary description: AdSd+1 d − 1 two gravitating systems are connected with each other via the transparent boundary condition at the defect. • Intermediate description: the holographic dual of is classical gravity spacetime. • Bulk description: BCFTd AdSd+1 The wedge holographic dictionary for the ( + 1)- dimensional bulk is stated as: . Therefore it is a co-dimension two holography. Now let us understand the how this duality exists. d holographic dual of the (d−1)-dimensional defect conformal field theory is the classical gravity in (d+1)- dimensions Braneworld holography [142,143] relates first and second line whereas AdS/CFT correspondence [17] between the dynamical gravity on the Karch-Randall brane and defect CFT connects second and third line. Therefore, ( + 1) Wedge holography helps us in getting the Page curve of the black holes similar to doubly holographic setup discussed in 5.3.2. One is required to compute the entanglement entropies of Hartman-Maldacena and island surfaces and plot of these entropies with time will give the Page curve. classical gravity in d bulk is dual to CFTd−1 at the defect. [1] We have already written the formula in (5.1), here we are writing the covariant form of (5.1). In this formula, a and i, j represents the tangential and normal directions. This paper is under CC 4.0 license. available on arxiv

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