# Scalar charges and pulsar-timing observables in the presence of nonminimally coupled scalar fields

## TL;DR

This paper examines how nonminimally coupled scalar fields in scalar-tensor theories affect pulsar-timing tests, showing that positive coupling values can evade constraints even with scalarization.

## Contribution

It provides the first analysis of pulsar-timing constraints on scalar-tensor theories with nonminimal coupling, highlighting conditions under which these theories can pass observational tests.

## Key findings

- Positive nonminimal coupling $\xi$ allows evasion of pulsar-timing constraints.
- Scalar charges are computed for nonminimally coupled scalar fields.
- Spontaneous scalarization does not necessarily violate pulsar-timing tests.

## Abstract

Pulsar-timing has become a celebrated tool for probing modifications to General Relativity in the strong-field surroundings of neutron stars. Here we investigate whether scalar-tensor theories that incorporate a nonminimally coupled scalar degree of freedom may pass pulsar-timing tests, by computing the scalar charges entering such observables. In particular we show that for positive values of the nonminimal coupling $\xi$, pulsar-timing constraints may be evaded even in the presence of spontaneous scalarization.