Neutron stars in Gauss-Bonnet extended Starobinsky gravity

TL;DR

This paper explores how Gauss-Bonnet extended Starobinsky gravity affects neutron star properties, revealing significant differences from general relativity that could be observed with future high-precision measurements.

Contribution

It provides the first detailed analysis of neutron stars in Gauss-Bonnet extended Starobinsky gravity, highlighting the impact of higher-curvature terms on stellar structure and moment of inertia.

Findings

Significant differences in neutron star moment of inertia compared to general relativity.

Higher-curvature effects alter neutron star structure.

Potential for future observations to detect deviations from GR.

Abstract

Recently, a class of Gauss-Bonnet extended Starobinsky gravity was proposed, allowing black holes to carry ghost-free massive scalar hair for the first time without requiring additional matter fields. This intriguing feature offers a new perspective for understanding higher-curvature pure gravity and highlights the importance of further studying the potential effects of Gauss-Bonnet extensions in gravitational systems beyond black holes. In this study, we investigate the properties of neutron stars within this model, focusing on how the higher-curvature terms, particularly the coupling between the Gauss-Bonnet term and the curvature-squared term, impact the stellar structure. We present a detailed analysis of these effects and compute the moment of inertia for rotating neutron stars under the slow-rotation approximation. The substantial differences in the moment of inertia between general relativity and Gauss-Bonnet extended Starobinsky gravity are expected to be detectable through future high-precision observations.