Dynamical transition to spontaneous scalarization in neutron stars: The massive scalar field scenario

TL;DR

This paper investigates how a massive scalar field influences the dynamical transition to spontaneous scalarization in neutron stars, demonstrating that the mass term can suppress observational constraints and affect stellar mass.

Contribution

It introduces a numerical analysis of scalar-tensor gravity with a massive scalar field, highlighting its effects on neutron star scalarization and observational constraints.

Findings

Mass term suppresses scalar field range, easing observational constraints.

Scalar field mass impacts the total mass of neutron stars.

Dynamical transition to scalarization can be avoided in massive scalar scenarios.

Abstract

We analyze numerically the dynamical transition to spontaneous scalarization in neutron stars in the framework of a scalar-tensor theory of gravity where the scalar field is free but massive, and it is coupled nonminimally to gravity in the Jordan frame. We show that the quasistatic configuration of the star that settles after the transition can avoid the observational constraints imposed on the amount of scalarization by several observations in binary systems due to the presence of the mass term, which suppresses the range of the scalar field. We also study the impact of the scalar field mass on the total mass of the star relative to the massless scenario.