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arXiv · 1708.00493

A cosmological open quantum system

Sarah Shandera·Nishant Agarwal·Archana Kamal
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Abstract

We derive the evolution equation for the density matrix of a UV- and IR- limited band of comoving momentum modes of the canonically normalized scalar degree of freedom in two examples of nearly de Sitter universes. Including the effects of a cubic interaction term from the gravitational action and tracing out a set of longer wavelength modes, we find that the evolution of the system is non-Hamiltonian and non-Markovian. We find linear dissipation terms for a few modes with wavelength near the boundary between system and bath and nonlinear dissipation terms for all modes. The non-Hamiltonian terms persist to late times when the scalar field dynamics is such that the curvature perturbation continues to evolve on super-Hubble scales.

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Sarah Shandera, Nishant Agarwal, Archana Kamal. 2018-12-13. A cosmological open quantum system. https://doi.org/10.1103/physrevd.98.083535

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