On the possibility of setting a new constraint to scalar-tensor theories

TL;DR

This paper explores the potential to constrain scalar-tensor theories of gravity by examining the stability differences of neutron stars compared to General Relativity, aiming to identify new observational constraints.

Contribution

It proposes a novel approach to constrain scalar-tensor theories by analyzing neutron star stability, expanding the testing framework beyond current solar system and pulsar timing limits.

Findings

Neutron star stability varies significantly in certain scalar-tensor theories.

Potential for new observational constraints on scalar-tensor theories.

Highlights unexplored parameter space where theories remain viable.

Abstract

Scalar-tensor theories (STTs) are a widely studied alternative to General Relativity (GR) in which gravity is endowed with an additional scalar degree of freedom. Although severely constrained by solar system and pulsar timing experiments, there remains a large set of STTs which are consistent with all present day observations. In this paper, we investigate the possibility of probing a yet unconstrained region of the parameter space of STTs based on the fact that stability properties of highly compact neutron stars in these theories may radically differ from those in GR.