Novel quantum initial conditions for inflation

TL;DR

This paper introduces a new method for setting initial conditions in inflationary models based on minimizing the renormalized stress-energy tensor, which could lead to observable differences from traditional approaches.

Contribution

It proposes a novel approach for initial conditions in inflation, valid in rapidly changing spacetimes, and compares its implications with traditional methods.

Findings

New initial conditions based on stress-energy tensor minimization

Potential observational distinguishability of the new approach

Application to kinetically dominated universe scenarios

Abstract

We present a novel approach for setting initial conditions on the mode functions of the Mukhanov Sazaki equation. These conditions are motivated by minimisation of the renormalised stress-energy tensor, and are valid for setting a vacuum state even in a context where the spacetime is changing rapidly. Moreover, these alternative conditions are potentially observationally distinguishable. We apply this to the kinetically dominated universe, and compare with the more traditional approach.