paint-brush
Relaxing cosmological constraints on current neutrino masses: Parameter Estimation by@cosmological
121 reads

Relaxing cosmological constraints on current neutrino masses: Parameter Estimation

Too Long; Didn't Read

In this paper, researchers present a mass-varying neutrino model driven by scalar field dark energy, relaxing the upper bound on current neutrino mass.
featured image - Relaxing cosmological constraints on current neutrino masses: Parameter Estimation
Cosmological thinking: time, space and universal causation  HackerNoon profile picture

This paper is available on arxiv under CC 4.0 license.

Authors:

(1) Vitor da Fonseca, Instituto de Astrof´ısica e Ciˆencias do Espa¸co, Faculdade de Ciˆencias da Universidade de Lisboa;

(2) Tiago Barreiro, Instituto de Astrof´ısica e Ciˆencias do Espa¸co, Faculdade de Ciˆencias da Universidade de Lisboa and 2ECEO, Universidade Lus´ofona;

(3) Nelson J. Nunes, Instituto de Astrof´ısica e Ciˆencias do Espa¸co, Faculdade de Ciˆencias da Universidade de Lisboa.

IV. PARAMETER ESTIMATION

A. Methodology





The likelihoods are minimized using the Monte Carlo code of the MontePython parameter estimation package [62, 63], which samples the parameter space and the posterior probability distributions using a Metropolis-Hastings algorithm with the flat priors specified in Table I. The size of the prior intervals is sufficient for the corresponding posteriors to fall exponentially within them, except for the parameter β as we will discuss later.


TABLE I: Flat priors for the sampled model and cosmological parameters.


B. Main results

The results of the likelihood analysis are summarized in Table II, which lists the constraints on the cosmological parameters obtained with the Plk18+BAO data set for both the uncoupled (β = 0) scalar field model and the coupled MaVaN model. They lead to several remarkable conclusions.






FIG. 7: Constraints obtained with the Plk18+BAO data set on the additional parameters. Probability distributions and 2D marginalised contours (68% and 95% CL).



TABLE III: Constraints on present neutrino mass in eV and on the dark energy parameter λ, for different coupling values β.


L O A D I N G
. . . comments & more!

About Author

Cosmological thinking: time, space and universal causation  HackerNoon profile picture
Cosmological thinking: time, space and universal causation @cosmological
From Big Bang's singularity to galaxies' cosmic dance the universe unfolds its majestic tapestry of space and time.

TOPICS

Languages

THIS ARTICLE WAS FEATURED IN...