Compact Stars in Vector-Tensor-Horndeski Theory of Gravity

TL;DR

This paper investigates the properties of compact stars within a modified gravity framework that extends general relativity by incorporating a non-minimally coupled vector field using Horndeski formalism, avoiding ghost degrees of freedom.

Contribution

It introduces a novel vector-tensor Horndeski gravity model and analyzes its implications for the structure of compact stars.

Findings

Compact star solutions are derived within the new theory.

The model avoids Ostrogradsky ghost instabilities.

Potential differences from general relativity in star properties are discussed.

Abstract

In this paper, we will analyse a theory of modified gravity, in which the field content of general relativity will be increased to include a vector field. We will use the Horndeski formalism to non-minimally couple this vector field to the metric. As we will be using the Horndeski formalism, this theory will not contain Ostrogradsky ghost degree of freedom. We will analyse compact stars using this Vector-Tensor-Horndeski theory.