Baryogenesis from ultra-slow-roll inflation

TL;DR

This paper explores how ultra-slow-roll inflation can induce baryogenesis via the Affleck-Dine mechanism, linking primordial black hole formation with the observed matter-antimatter asymmetry and dark matter abundance.

Contribution

It demonstrates a novel scenario where USR inflation triggers baryogenesis through scalar condensates with unconventional initial conditions, connecting PBH formation to baryon asymmetry.

Findings

USR inflation enhances curvature perturbations and PBH formation.

Scalar condensates can generate baryon asymmetry from USR-induced initial conditions.

Parameter space aligns PBH dark matter contribution with baryon asymmetry constraints.

Abstract

The ultra-slow-roll (USR) inflation represents a class of single-field models with sharp deceleration of the rolling dynamics on small scales, leading to a significantly enhanced power spectrum of the curvature perturbations and primordial black hole (PBH) formation. Such a sharp transition of the inflationary background can trigger the coherent motion of scalar condensates with effective potentials governed by the rolling rate of the inflaton field. We show that a scalar condensate carrying (a combination of) baryon or lepton number can achieve successful baryogenesis through the Affleck-Dine mechanism from unconventional initial conditions excited by the USR transition. Viable parameter space for creating the correct baryon asymmetry of the Universe naturally incorporates the specific limit for PBHs to contribute significantly to dark matter, shedding light on the cosmic coincidence problem between the baryon and dark matter densities today.