Jun 5 – 6, 2025
ETH Zurich
UTC timezone

Evolution of gauge-invariant scalar perturbations from inflation to reheating

Jun 5, 2025, 4:45 PM
15m
Siemens Auditorium (HIT E 51) (ETH Zurich)

Siemens Auditorium (HIT E 51)

ETH Zurich

Wolfgang-Pauli-Strasse 27 HIT Building CH-8093 Zürich
Theory (no GW) Theory (no GW)

Speaker

Alica Rogelj (University of Bern (AEC, ITP))

Description

We assume that at a late stage of inflation, a scalar inflaton field, a thermal plasma, and a spacetime metric coexisted and interacted with each other. We expand them to the linear order around a homogeneous background and combine the perturbations into a set of gauge invariant variables. For the latter we derive evolution equations in the framework of smooth reheating. Having resolved some numerical challenges, we provide solutions for a set of benchmarks, from inflation all the way until radiation domination. In particular, our solution exhibits some key features of the inflationary paradigm, for example: gauge invariant 'curvature perturbations' obtain the same constant value when they are outside of the Hubble horizon and experience acoustic oscillations upon re-entry. The talk is based on 2407.17074.

Authors

Alica Rogelj (University of Bern (AEC, ITP)) Prof. Mikko Laine (University of Bern (AEC, ITP)) Dr Simona Procacci (University of Geneva)

Presentation materials