Open systems in cosmology

1 Jul 2026, 11:00
45m
MR3

MR3

Department of Applied Mathematics and Theoretical Physics Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA United Kingdom

Speaker

Santiago Agui-Salcedo

Description

There is an increasing interest in the interplay between Open Quantum Systems and Inflationary Physics. A time-dependent background and limited access to the degrees of freedom invite the use of Open Quantum systems. It provides a more general framework than the unitary time evolution of a free state. In this talk, I will present a field-theoretic framework for such open systems based on the Schwinger-Keldysh path integral, showing how UV unitarity constrains the resulting influence functional and how dissipation changes the realization of global and gauge symmetries. I will illustrate this framework with applications to inflation and dark energy, where it leads to observational constraints from the CMB and DESI data.

Presentation materials