Stability of relativistic Bondi accretion in Schwarzschild-(anti-)de Sitter spacetimes

TL;DR

This paper analyzes the stability of relativistic Bondi accretion flows in Schwarzschild-(anti-)de Sitter spacetimes, demonstrating stability under certain conditions using Moncrief's method.

Contribution

It extends stability analysis to relativistic accretion flows in Schwarzschild-(anti-)de Sitter spacetimes, including isothermal and polytropic cases, under the test-fluid approximation.

Findings

Global isothermal flows in Schwarzschild-anti-de Sitter are stable.

Stability of flows in Schwarzschild-de Sitter depends on boundary conditions.

Polytropic flows can also be stable under suitable conditions.

Abstract

In a recent paper we investigated stationary, relativistic Bondi-type accretion in Schwarzschild-(anti-)de Sitter spacetimes. Here we study their stability, using the method developed by Moncrief. The analysis applies to perturbations satisfying the potential flow condition. We prove that global isothermal flows in Schwarzschild-anti-de Sitter spacetimes are stable, assuming the test-fluid approximation. Isothermal flows in Schwarzschild-de Sitter geometries and polytropic flows in Schwarzschild-de Sitter and Schwarzschild-anti-de Sitter spacetimes can be stable, under suitable boundary conditions.