Semiclassical states for quantum cosmology

TL;DR

This paper develops a method to construct semiclassical states in quantum cosmology using polymer quantization, enabling analysis of quantum corrections and the universe's initial state.

Contribution

It introduces a prescription for creating semiclassical matter-geometry states in homogeneous isotropic models within a polymer quantization framework.

Findings

States peak on classical configurations

Method to compute quantum corrections

Application to universe's initial state

Abstract

In a metric variable based Hamiltonian quantization, we give a prescription for constructing semiclassical matter-geometry states for homogeneous and isotropic cosmological models. These "collective" states arise as infinite linear combinations of fundamental excitations in an unconventional "polymer" quantization. They satisfy a number of properties characteristic of semiclassicality, such as peaking on classical phase space configurations. We describe how these states can be used to determine quantum corrections to the classical evolution equations, and to compute the initial state of the universe by a backward time evolution.