Inflaton Decay in an Alpha Vacuum

TL;DR

This paper investigates inflaton decay in de Sitter space's alpha vacua, revealing alpha-dependent effects and proposing a causality-preserving prescription that yields alpha-independent results, impacting quantum field theory in curved spacetime.

Contribution

It introduces an alpha-dependent decay rate analysis and a modified time ordering prescription, showing how to obtain consistent, alpha-independent results in alpha vacua.

Findings

Alpha-dependent Bose enhancement observed in inflaton decay.

No non-renormalizable divergences found in alpha vacua.

A causality-preserving prescription yields alpha-independent decay results.

Abstract

We study the alpha vacua of de Sitter space by considering the decay rate of the inflaton field coupled to a scalar field placed in an alpha vacuum. We find an {\em alpha dependent} Bose enhancement relative to the Bunch-Davies vacuum and, surprisingly, no non-renormalizable divergences. We also consider a modified alpha dependent time ordering prescription for the Feynman propagator and show that it leads to an alpha independent result. This result suggests that it may be possible to calculate in any alpha vacuum if we employ the appropriate causality preserving prescription.