Jun 1 – 2, 2023
ZiF | Bielefeld University
Europe/Berlin timezone

Gravitational wave background from vacuum and thermal fluctuations during axion-like inflation

Jun 1, 2023, 5:20 PM
Plenarsaal (ZiF | Bielefeld University)


ZiF | Bielefeld University

Methoden 1 33615 Bielefeld


Philipp Klose (Bern University)


We revisit the framework of axion-like inflation and consider a warm inflation scenario in which the inflaton couples to the topological charge density of non-Abelian gauge bosons whose self-interactions result in a rapidly thermalizing heat bath. Including both dispersive (mass) and absorptive (friction) effects, we find that the system remains in a weak regime of warm inflation (thermal friction ≪ Hubble rate) for phenomenologically viable parameters. We derive an interpolating formula for vacuum and thermal production of tensor perturbations in generic warm inflation scenarios, and find that the perturbations exhibit a model-independent f^3 frequency shape in the LISA window, with a coefficient that measures the maximal shear viscosity of the thermal epoch.

Primary authors

Prof. Mikko Laine (Bern University) Philipp Klose (Bern University) Ms Simona Procacci (Bern University)

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