Speaker
Description
We study post-inflationary oscillon dynamics in an E-model $\alpha$-attractor scenario in which the inflaton is kinetically coupled to an ultralight axion. We perform nonlinear three-dimensional lattice simulations using GABE to investigate how this interaction affects both the formation of oscillons and their subsequent evolution. We find that oscillons can still form in the presence of kinetic coupling for $\mu_V \lesssim 0.08\,M_{\mathrm{Pl}}$. However, in the parameter regime we can reliably evolve, fully formed oscillons are destabilized at later times for $\mu_W \gtrsim 0.06\,M_{\mathrm{Pl}}$ by backreaction from the populated $\chi$ sector. Although our results do not provide direct evidence for oscillon decay into the $\chi$ sector, they show that kinetic coupling can destabilize otherwise long-lived oscillons and thereby modify the post-inflationary dynamics of the E-model $\alpha$-attractor. This points to a novel mechanism in which backreaction governs oscillon lifetimes.
| Other topic / keywords: | oscillons, preheating, reheating |
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