Effects of the stress evolution process on the thermal stability of thin accretion discs

The stress evolution process is taken into account in the linear stability analysis of standard thin accretion discs. We find that the growth rate of thermally unstable modes can decrease significantly owing to the stress delay, which may help to understand the quasi-periodic variability of GRS 1915+105. We also discuss the possible application of stress evolution to the stability of the Shapiro-Lightman-Eardley disc.