Relativistic Dissipative Accretion Flow onto Black Hole

TL;DR

This paper discusses the development of a causal relativistic theory of dissipative accretion flows onto black holes, highlighting differences from classic laws and presenting new theorems and stability analysis.

Contribution

It introduces the application of Extended Irreversible Thermodynamics to relativistic accretion flows and presents new theorems and stability results.

Findings

EIT clarifies key properties of relativistic dissipative flows.

A dissipative instability of a relativistic perfect fluid solution is demonstrated.

The contrast between EIT and classic laws of dissipation is emphasized.

Abstract

Dissipations, e.g. heat flow and bulk and shear viscosities, cause the transport of energy, momentum and angular momentum, which is the essence of accretion of matters onto celestial objects. Dissipations are usually described by the Fourier and Navier-Stokes laws ("classic laws" of dissipations). However the classic laws result in an infinitely fast propagation of dissipations. In relativistic formulation, the classic laws of dissipations violate the causality, and hence no relativistic theory of accretion flow onto celestial object is formulated. In this short report, we summarize the causal dissipative hydrodynamics, so-called "Extended Irreversible Thermodynamics" (EIT), with a supplemental comment of which the original works of EIT are not aware, and then show two theorems about relativistic dissipative flows around a Schwarzschild black hole. By these theorems, a significant property of EIT in contrast with classic laws of dissipations is clarified, and a dissipative instability of an exact solution of relativistic perfect fluid flow is also obtained.