Generalized Oppenheimer-Snyder Gravitational Collapse into Regular Black holes

TL;DR

This paper models the gravitational collapse of a star into regular black holes using a generalized Oppenheimer-Snyder approach, revealing detailed interior dynamics and constructing a new family of such black holes with specific properties.

Contribution

It introduces a generalized collapse model for regular black holes, including explicit interior solutions and a new two-parameter family of such black holes.

Findings

Interior horizons and stellar surface are expressed as functions of proper time.

Stellar matter follows a polytropic equation of state, with strong energy condition violations at small radii.

Constructs a new family of regular black holes with smooth interior matching.

Abstract

We shall study the formation of a particular class of regular black holes from the gravitational collapse of a massive star. The inside geometry is described by spatially flat Friedmann-Robertson-Walker metric and the stellar matter is distributed uniformly without any pre-assumption about its equation of state. Our model is a generalization of Oppenheimer-Snyder collapse for regular black holes. We have obtained the density and pressure of star by applying the condition of smooth joining of metrics at the freely falling surface of star. Specifying the regular black holes to Hayward and Bardeen cases, we see that the stellar matter is described by a polytropic equation of state and moreover, for the radius smaller than a certain value, the strong energy condition becomes invalid. Then for both black holes, the interior apparent and event horizons and also the stellar surface are obtained as functions of the proper time of star. At the end, we have constructed a new two parametric family of regular black holes jointed smoothly to the flat Friedmann-Robertson-Walker interior metric of a polytropic star with an arbitrary index.