Berlin 2014 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 9: Classical theory of General Relativity I

GR 9.3: Talk

Tuesday, March 18, 2014, 11:55–12:15, SPA SR220

Non-perfect-fluid space-times in thermodynamic equilibrium and generalized Friedmann equations — •Konrad Schatz, Horst-Heino von Borzeszkowski, and Thoralf Chrobok — Institut für Theoretische Physik, TU-Berlin, Germany

Assuming homogeneous and parallax-free space-times, in the case of thermodynamic equilibrium, we construct the energy-momentum tensor of non-perfect fluids. To this end, first, we integrate the propagation equations for the matter functions, i.e., for energy density, isotropic and anisotropic pressures, and heat-flux. This provides these functions in terms of the structure constants of the three-dimensional isometry group of homogeneity and, espectively, of the kinematical quantities, expansion, rotation and acceleration. Second, the matter functions are combined to the energy-momentum tensor. Using Einstein's equations, the constants of integration can be determined such that one gets bounds on the kinematical quantities and finds a generalized form of the Friedmann equations. Finally, it is shown that, for a perfect fluid, the Friedmann and Gödel models can be recovered. All this is derived without assuming any equations of state or other specific thermodynamic conditions.