Primordial black holes and inflation from double-well potentials

Karam, Alexandros and Koivunen, Niko and Tomberg, Eemeli and Racioppi, Antonio and Veermäe, Hardi (2023) Primordial black holes and inflation from double-well potentials. Journal of Cosmology and Astroparticle Physics, 2023 (9): 002. ISSN 1475-7516

Abstract

We investigate the formation of large peaks in the inflationary curvature power spectrum from double-well potentials. In such scenarios, the initial CMB spectrum is created at large field values. Subsequently, the inflaton will cross one of the minima and will decelerate rapidly as it reaches the local maximum at the origin, either falling back or crossing it. During this final phase, a significant peak in the curvature power spectrum can be generated. Our analysis reveals that this class of models produces more pronounced peaks than most quasi-inflection point scenarios with less tuning for the model parameters. Finally, we construct an explicit theoretically motivated inflationary scenario that is consistent with the latest CMB observations and capable of generating sufficiently large curvature perturbations for primordial black holes.