Gravitational collapse of homogeneous perfect fluid in HOG theories

TL;DR

This study explores gravitational collapse in high order gravity theories with scalar fields and perfect fluids, showing that collapse typically results in black hole formation, with some cases leading to naked singularities.

Contribution

It demonstrates the generic evolution of collapsing homogeneous perfect fluid models in HOG theories toward black hole formation, including analysis of naked singularities in special cases.

Findings

Collapse generally leads to black hole formation

Singularities form in finite time during collapse

Naked singularities occur in specific special cases

Abstract

This paper investigates the evolution of collapsing FRW models with a scalar field having the potential which arises in the conformal frame of high order gravity theories, coupled to matter described by a perfect fluid with energy density $\rho$ and pressure $p$, obeying a barotropic equation of state. The solutions are shown to evolve generically to a singular state in a finite time and they are used as sources for radiating objects undergoing complete gravitational collapse. Although these singularities may be naked in some special case, it is shown that generically a black hole forms.