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arXiv · 1006.2376

Coupled scalar fields in a flat FRW universe: renormalisation

Jurgen Baacke·Laura Covi·Nina Kevlishvili
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Abstract

We study the non-equilibrium dynamics of a system of coupled scalar fields in a Friedmann-Robertson-Walker (FRW) universe. We consider the evolution of spatially homogeneous "classical" fields and of their quantum fluctuations including the quantum backreaction in the one-loop approximation. We discuss in particular the dimensional regularisation of the coupled system and a special subtraction procedure in order to obtain the renormalised equations of motion and the renormalised energy-momentum tensor and ensure that the energy is well-defined and covariantly conserved. These results represent at the same time a theoretical analysis and a viable scheme for stable numerical simulations. As an example for an application of the general formalism, we present simulations for a hybrid inflationary model.

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Jurgen Baacke, Laura Covi, Nina Kevlishvili. 2010-06-11. Coupled scalar fields in a flat FRW universe: renormalisation. https://doi.org/10.1088/1475-7516/2010/08/026

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