Hostname: page-component-7b7567c8c-wxvwp Total loading time: 0 Render date: 2026-11-15T20:39:19.639Z Has data issue: false hasContentIssue false

An exact solution in a gravitating fluid with a density-dependent viscosity

Published online by Cambridge University Press:  04 November 2013

NIKHIL CHAKRABARTI
Affiliation:
Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064, India (nikhil.chakrabarti@saha.ac.in)
HANS SCHAMEL
Affiliation:
Theoretical Physics, University of Bayreuth, D-95440 Bayreuth, Germany
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

An exact nonlinear solution for a cold fluid in presence of a gravitational field and viscous dissipation is obtained using Lagrange variable. It is shown that with a density-dependent viscosity the nonlinear equation can be exactly solved. The solution indicates that in absence of viscosity and initial fluid velocity shear, density collapse occurs at time of the order of inverse Jeans frequency. The effect of viscosity is to delay the collapse but it can not halt the collapse. The initial fluid velocity shear can act in both directions: a positive one leads to delay, a negative one to a speeding up of the density collapse. This nonlinear solution may have some bearing with the structure formations in the universe.