http://arxiv.org/abs/2005.12923
A new truncation scheme based on the cumulant expansion of the one-particle phase-space distribution function for dark matter particles is developed. Extending the method of moments in relativistic kinetic theory, we derive evolution equations which supplement the covariant conservation of the energy-momentum tensor and particle number current. Truncating the cumulant expansion we obtain a closed, covariant and hyperbolic system of equations which can be used to model the evolution of a general relativistic non-ideal fluid. As a working example we consider a Friedmann-Lema\^itre-Robertson-Walker cosmology with dynamic pressure and solve for the time evolution of the effective equation of state parameter.
A. Erschfeld, S. Floerchinger and M. Rupprecht
Thu, 28 May 20
42/55
Comments: 10 pages, 1 figure
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