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arXiv · gr-qc/9905015

Thermodynamic equilibrium in the expanding universe

Winfried Zimdahl·Alexander B. Balakin
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Abstract

We show that a relativistic gas may be at ``global'' equilibrium in the expanding universe for any equation of state $0 < p \leq ρ/3$, provided that the gas particles move under the influence of a self-interacting, effective one-particle force in between elastic binary collisions. In the force-free limit we recover the equilibrium conditions for ultrarelativistic matter which imply the existence of a conformal timelike Killing vector.

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Winfried Zimdahl, Alexander B. Balakin. 1999-05-06. Thermodynamic equilibrium in the expanding universe. https://doi.org/10.1023/a%3A1026741228100

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