Slowly rotating topological neutron stars -- universal relations and epicyclic frequencies

TL;DR

This paper investigates slowly rotating topological neutron stars within tensor-multi-scalar gravity theories, examining their universal relations and epicyclic frequencies to aid in testing gravity through astrophysical observations.

Contribution

It extends the study of topological neutron stars to rotation and explores universal relations and orbital properties in tensor-multi-scalar gravity.

Findings

Universal relations hold for topological neutron stars.

Properties of innermost stable circular orbits are characterized.

Epicyclic frequencies are analyzed for observational relevance.

Abstract

In the modern era of abundant X-ray detections and the increasing momentum of gravitational waves astronomy, tests of General Relativity in strong field regime become increasingly feasible and their importance for probing gravity cannot be understated. To this end, we study the characteristics of slowly rotating topological neutron stars in the tensor-multi-scalar theories of gravity following the static study of this new type of compact objects by two of the authors. We explore the moment of inertia and verify that universal relations known from General Relativity hold for this new class of compact objects. Furthermore, we study the properties of their innermost stable circular orbits (ISCO) and the epicyclic frequencies due to the latter's hinted link to observational quantities such as quasi-periodic X-ray spectrum features.