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Symmetry 2000
Entropy 2002, 4(3), 49-64; doi:10.3390/e4030049

Conformal Symmetry and Cosmological Entropy Production

1,*  and 2,*
1 Fachbereich Physik, Universität 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
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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 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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

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