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The dynamics of cosmological perturbations in thermal $λϕ^4$ theory

Herbert Nachbagauer·Anton K. Rebhan·Dominik J. Schwarz
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Abstract

Using a recent thermal-field-theory approach to cosmological perturbations, the exact solutions that were found for collisionless ultrarelativistic matter are generalized to include the effects from weak self-interactions in a $λϕ^4$ model through order $λ^{3/2}$. This includes the effects of a resummation of thermal masses and associated nonlocal gravitational vertices, thus going far beyond classical kinetic theory. Explicit solutions for all the scalar, vector, and tensor modes are obtained for a radiation-dominated Einstein-de Sitter model containing a weakly interacting scalar plasma with or without the admixture of an independent component of perfect radiation fluid.

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Herbert Nachbagauer, Anton K. Rebhan, Dominik J. Schwarz. 1995-10-23. The dynamics of cosmological perturbations in thermal $λϕ^4$ theory. https://doi.org/10.1103/physrevd.53.5468

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