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

Axion inflation in the strong-backreaction regime: Lifetime of the Anber-Sorbo solution

Jun 2, 2023, 9:00 AM
20m
Plenarsaal (ZiF | Bielefeld University)

Plenarsaal

ZiF | Bielefeld University

Methoden 1 33615 Bielefeld
Talk

Speaker

Richard von Eckardstein (Institute for Theoretical Physics, University of Münster)

Description

Axion inflation is an attractive particle physics model of inflation with a rich phenomenology, due to the parity violating production of gauge-fields in this model, which may have implications for the production of gravitational waves, scalar perturbations and the baryon asymmetry. In recent years, a scenario with strong back-reaction of the gauge fields onto the inflaton in this model has been studied extensively, using different methods such as lattice simulations, solving the system numerically in Fourier space, or a novel technique called the gradient expansion formalism. Additionally, a well known analytical solution to Axion inflation exists. In this so-called Anber-Sorbo solution, the gauge field production counter-acts the scalar potential gradient, which may be too steep to allow for traditional slow-roll inflation. Our aim is to study the lifetime of the Anber-Sorbo solution using the gradient expansion formalism, motivated by a recent analytical calculation based on this solution. We initially rely on the approximation of a constant Hubble parameter used in the analytical study, but then make use of the full power of the gradient expansion formalism to examine the impact of a varying Hubble-rate. We find that the lifetime of the Anber-Sorbo solution can be extended to several e-folds at the cost of a high degree of fine tuning of the initial conditions.

Primary authors

Prof. Kai Schmitz (Institute for Theoretical Physics, University of Münster) Prof. Lorenzo Sorbo (ACFI, Department of Physics, University of Massachusetts) Prof. Marco Peloso (Dipartimento di Fisica e Astronomia, Università di Padova) Dr Oleksandr Sobol (Institute for Theoretical Physics, University of Münster) Richard von Eckardstein (Institute for Theoretical Physics, University of Münster)

Presentation materials