Next Article in Journal
Extremal Black Holes in Supergravity and the Bekenstein-Hawking Entropy
Previous Article in Journal
Symmetry 2000
Entropy 2002, 4(3), 49-64; doi:10.3390/e4030049

Conformal Symmetry and Cosmological Entropy Production

1,*  and 2,*
1 Fachbereich Physik, Universit├Ąt Konstanz PF M678, D-78457 Konstanz, Germany 2 Department of General Relativity and Gravitation Kazan State University, 420008 Kazan, Russia
* Authors to whom correspondence should be addressed.
Received: 16 August 2001 / Accepted: 3 March 2002 / Published: 10 March 2002
Download PDF [196 KB, uploaded 24 February 2015]


Introducing an effective refraction index of an isotropic cosmic medium, we investigate the cosmological fluid dynamics which is consistent with a conformal, timelike symmetry of a corresponding "optical" metric. We demonstrate that this kind of symmetry is compatible with the existence of a negative viscous pressure and, consequently, with cosmological entropy production. We establish an exactly solvable model according to which the viscous pressure is a consequence of a self-interacting one-particle force which is self-consistently exerted on the microscopic particles of a relativistic gas. Furthermore, we show that a suficiently high decay rate of the refraction index of an ultrarelativistic cosmic medium results in an in ationary expansion of the universe.
Keywords: general relativity; cosmology; thermohydrodynamics; kinetic theory; inflationary universe general relativity; cosmology; thermohydrodynamics; kinetic theory; inflationary universe
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote |
MDPI and ACS Style

Zimdahl, W.; Balakin, A.B. Conformal Symmetry and Cosmological Entropy Production. Entropy 2002, 4, 49-64.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here


[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert