Gauge Field Dynamics During Inflation

Gauge Field Dynamics During Inflation
Oksana Iarygina, Nordita, Stockholm
Oksana Iarygina
Date and time: Fri, Feb 16, 2024 - 2:15pm
Location: LGRT 419B
Category: ACFI Seminar
Abstract:

Nowadays, the search for primordial gravitational waves is mainly focused on the parity-odd polarization pattern in the CMB - the B-modes. A correct interpretation of B-mode measurements strongly relies on understanding their production mechanism. One intriguing scenario is gravitational waves generation by gauge fields. I will discuss the viability of inflation with a spectator sector comprised of non-Abelian gauge fields coupled through a higher order operator, so-called spectator Gauge-flation. Moreover, the tachyonic amplification of the gauge fields during inflation leads to significant backreaction on the inflaton, leading to a sudden drop of its velocity. I will show how the backreaction on axion-SU(2) dynamics during inflation leads to a new dynamical attractor solution for the axion field and the vacuum expectation value of the gauge field. These effects lead to characteristic oscillatory features in the primordial gravitational wave background that are potentially detectable with upcoming gravitational wave detectors.