Analytic approximation and an improved method for computing the stress-energy of quantized scalar fields in Robertson-Walker spacetimes

TL;DR

This paper introduces an improved adiabatic regularization method for calculating the stress-energy tensor of quantized scalar fields in Robertson-Walker spacetimes, applicable to arbitrary mass and curvature coupling, with analytic approximations for massless cases.

Contribution

It presents a novel, more versatile method for computing the stress-energy tensor in dynamic spacetimes, extending previous static spacetime approaches.

Findings

Method works for arbitrary mass and curvature coupling

Provides analytic approximation for massless fields

Effective for spacetimes with compact spatial sections

Abstract

An improved method is given for the computation of the stress-energy tensor of a quantized scalar field using adiabatic regularization. The method works for fields with arbitrary mass and curvature coupling in Robertson-Walker spacetimes and is particularly useful for spacetimes with compact spatial sections. For massless fields it yields an analytic approximation for the stress-energy tensor that is similar in nature to those obtained previously for massless fields in static spacetimes.