Time variability of viscosity parameter in differentially rotating discs

Дата и время публикации : 2013-10-14T17:18:44Z

Авторы публикации и институты :
S. R. Rajesh (S. D. College, Allappuzha, India)
Nishant K. Singh (IUCAA, India, NORDITA, Sweden)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 21 pages, 3 figures
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE, physics.flu-dyn

Краткий обзор статьи: We propose a mechanism to produce fluctuation in the viscosity parameter ($alpha$) in differetially rotating discs. We carried out a nonlinear analysis of a general accretion flow, where any perturbation on the background $alpha$ was treated as a passive/slave variable in the sense of dynamical system theory. We demonstrate a complete physical picture of growth, saturation and final degradation of the perturbation as a result due to the nonlinear nature of coupled system of equations. The strong dependence of this fluctuation on the radial location in the accretion disc and the base angular momentum distribution is demonstrated. The growth of fluctuation is shown to have a time scale comparable to the radial drift time and hence the physical significance is discussed. The fluctuation is found to be a power law in time in the growing phase and we briefly discuss its statistical significance.

Category: Physics