Neutron star solutions with curvature induced scalarization in the extended Gauss-Bonnet scalar-tensor theories

TL;DR

This paper explores neutron star solutions in extended scalar-tensor theories where scalarization is driven by spacetime curvature, revealing new solutions formed through spontaneous scalarization unlike matter-induced cases.

Contribution

It introduces a novel class of neutron star solutions in ESTGB theories where scalarization is curvature-induced, expanding understanding of scalar-tensor gravity models.

Findings

Existence of new neutron star solutions via curvature-induced scalarization

Scalarization occurs in the strong curvature regime

Differences from matter-induced scalarization in standard theories

Abstract

In the present paper we study models of neutron stars in a class of extended scalar-tensor Gauss-Bonnet (ESTGB) theories for which the scalar degree of freedom is exited only in the strong curvature regime. We show that in the framework of the ESTGB theories under consideration there exist new neutron star solutions which are formed via spontaneous scalarization of the general relativistic neutron stars. In contrast to the spontaneous scalarization in the standard scalar-tensor theories which is induced by the presence of matter, in our case the scalarization is induced by the spacetime curvature.