Hydrodynamical Misner-Sharp Formulation for Gravitational Collapse in Scalar-Tensor Theories

TL;DR

This paper develops a new hydrodynamical formulation in scalar-tensor theories of gravity to analyze gravitational collapse, providing a framework for initial conditions and equilibrium states.

Contribution

It introduces a novel Misner-Sharp inspired hydrodynamical approach in the Einstein frame for scalar-tensor gravity, including equilibrium conditions and initial phase analysis.

Findings

Derived the Tolman-Oppenheimer-Volkoff condition in this framework

Presented initial collapse phases with junction condition analysis

Established a basis for further collapse simulations in scalar-tensor theories

Abstract

We study the problem of gravitational collapse in the context of scalar-tensor theories of Gravity. We introduce a new hydrodynamical formulation in the Einstein frame, inspired by that of Misner and Sharp. We obtain the equilibrium Tolman-Oppenheimer-Volkoff condition that we use to find valid initial states of the problem within this framework. For illustration purposes, we present the minimal version of the initial phases of the collapse together with an analysis of the corresponding junction conditions.