Interior perfect fluid scalar-tensor solution

TL;DR

This paper introduces a new exact scalar-tensor interior solution with a perfect fluid that is regular everywhere and smoothly matches an external solution, advancing the understanding of scalar-tensor theories in gravitational physics.

Contribution

It provides the first regular interior perfect fluid solution in a specific scalar-tensor theory with continuous matching to an external spacetime.

Findings

Solution is regular everywhere

Fluid pressure vanishes at a well-defined boundary

Smooth matching of metric and dilaton field to external solution

Abstract

We present a new exact perfect fluid interior solution for a particular scalar-tensor theory. The solution is regular everywhere and has a well defined boundary where the fluid pressure vanishes. The metric and the dilaton field match continuously the external solution.