Hydrodynamical activity in thin accretion disks

TL;DR

This paper extends an asymptotic analysis of thin accretion disks to include time-dependent behavior, demonstrating analytically that transient growth of disturbances can occur on the entire disk scale, impacting disk stability theories.

Contribution

It introduces a time-dependent extension to the asymptotic treatment of thin accretion disks, revealing transient growth phenomena not previously analyzed.

Findings

Transient growth of disturbances occurs on the global disk scale

Analytical demonstration of disturbance amplification in thin disks

Implications for hydrodynamical stability of accretion disks

Abstract

An asymptotic treatment of thin accretion disks, introduced by Klu\'zniak & Kita (2000) for a steady-state disk flow, is extended to a time-dependent problem. Transient growth of axisymmetric disturbances is analytically shown to occur on the global disk scale. The implications of this result on the theory of hydrodynamical thin accretion disks, as well as future prospects, are discussed.