Gauss-Bonnet boson stars

TL;DR

This paper constructs and analyzes boson stars within five-dimensional Gauss-Bonnet gravity, revealing how higher curvature corrections influence their structure, stability, and mass-radius relations compared to Einstein gravity.

Contribution

It introduces boson star solutions in (4+1)-dimensional Gauss-Bonnet gravity and explores how the coupling affects their properties and limits, highlighting differences from Einstein gravity.

Findings

Spiraling behavior disappears at high Gauss-Bonnet coupling.

Scalar field cannot reach arbitrarily high central values at large coupling.

Mass-radius relation becomes unique and similar to neutron stars at large coupling.

Abstract

We construct boson stars in (4+1)-dimensional Gauss-Bonnet gravity. We study the properties of the solutions in dependence on the coupling constants and investigate these in detail. While the "thick wall" limit is independent of the value of the Gauss-Bonnet coupling, we find that the spiraling behaviour characteristic for boson stars in standard Einstein gravity disappears for large enough values of the Gauss-Bonnet coupling. Our results show that in this case the scalar field can not have arbitrarily high values at the center of the boson star and that it is hence impossible to reach the "thin wall" limit. Moreover, for large enough Gauss-Bonnet coupling we find a unique relation between the mass and the radius (qualitatively similar to those of neutron stars) which is not present in the Einstein gravity limit.