Radiative falloff in black-hole spacetimes

TL;DR

This paper investigates how massless scalar fields decay over time in non-asymptotically flat black-hole spacetimes, specifically Schwarzschild-de Sitter and Schwarzschild-Einstein-de Sitter, highlighting the influence of cosmological horizons.

Contribution

It provides a detailed analysis of scalar field evolution in black-hole spacetimes with cosmological horizons, extending understanding beyond asymptotically flat cases.

Findings

Late-time decay influenced by cosmological horizons

Scalar field behavior transitions from pure Schwarzschild to cosmological region effects

Distinct evolution patterns in Schwarzschild-de Sitter and Schwarzschild-Einstein-de Sitter spacetimes

Abstract

This two-part contribution to the Proceedings of the Eighth Canadian Conference on General Relativity and Relativistic Astrophysics is devoted to the evolution of a massless scalar field in two black-hole spacetimes which are not asymptotically flat. In Part I (authored by Eric Poisson) we consider the evolution of a scalar field propagating in Schwarzschild-de Sitter spacetime. The spacetime possesses a cosmological horizon in addition to the usual event horizon. The presence of this new horizon affects the late-time evolution of the scalar field. In part II (authored by William G. Laarakkers) we consider the evolution of a scalar field propagating in Schwarzschild-Einstein-de Sitter spacetime. The spacetime has two distinct regions: an inner black-hole region and an outer cosmological region. Early on in the evolution, the field behaves as if it were in pure Schwarzschild spacetime. Later, the field learns of the existence of the cosmological region and alters its behaviour.