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**Authors:**

(1) Agustin Moreno;

(2) Francesco Ruscelli.

- Abstract
- Introduction
- Preliminaries
- The B-signature
- GIT sequence: low dimensions
- GIT sequence: arbitrary dimension
- Appendix A. Stability, the Krein–Moser theorem, and refinements and References

In this section, we discuss the notion of B-signature, or B-signs, introduced by the first author and Urs Frauenfelder in [FM], associated to a symmetric periodic orbit (see also [Ay22]).

Consider a Wonenburger matrix

The following result illustrates the uses of these signs, as they give information on the type of periodic orbit.

**Theorem 2 ([FMb]).** *A symmetric periodic orbit of a Hamiltonian system with two degrees of freedom is negative hyperbolic if and only if its two B-signs are different.*

This paper is available on arxiv under CC BY-NC-SA 4.0 DEED license.

L O A D I N G

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