Quantum tunneling during large field inflation

Abstract

Vacuum decays through quantum tunneling constitute a substantial part of inflationary theory If occurring at sufficiently close to the end of inflation, the corresponding implications on observables are manifold. In this study a family of large field potentials that inherit the possibility of primordial tunnelling events is analysed for a scalar inflaton; namely, they contain a positive metastable false vacuum and a true vacuum at the origin. Furthermore, the scalar field is considered in two different cases: minimally and non-minimally coupled to gravity. Thus, the tensor-to-scalar ratio, the scalar spectral index and the amplitude of scalar perturbations corresponding to these models are calculated and compared to CMB measurements. Furthermore, the process of tunnelling out of said false vacuum is described analytically as well as numerically. Finally, the consequences of tunelling in the treated descriptions of inflation are carried out also taking into account a scenario with cosmic friction by decay into abelian gauge-bosons