Gravitational collapse of matter fields in de Sitter spacetimes

TL;DR

This paper investigates the gravitational collapse of various matter fields in de Sitter spacetime, combining analytical and numerical methods to study horizon formation and evolution.

Contribution

It introduces a comprehensive analysis of matter collapse in de Sitter space using the quasilocal trapped surface formalism, covering diverse matter types and initial conditions.

Findings

Black hole and cosmological horizons evolve from marginally trapped surfaces.

Collapse dynamics depend on initial velocity and density profiles.

The quasilocal formalism effectively tracks horizon development.

Abstract

In this paper, we discuss the spherically symmetric gravitational collapse of matter fields in the de Sitter universe. The energy-momentum tensor of the matter field is assumed to admit a wide variety including dust, perfect fluids with equations of state, fluids with tangential and radial pressure, and with bulk and shear viscosity. Under different initial conditions imposed on the velocity and the density profiles, and by combining the results from exact analytical methods with those obtained from numerical techniques, we track the formation and evolution of spherical marginally trapped spheres as the matter suffers continual gravitational collapse. We show that the quasilocal formalism of trapped surfaces provides an ideal framework to study the evolution of horizons. More precisely, black hole and cosmological horizons may be viewed as the time development of marginally trapped surfaces.