Statistical Mechanics and Quantum Cosmology

TL;DR

This paper explores how statistical mechanics concepts like decoherence and dissipation can deepen understanding of quantum cosmology, challenging traditional assumptions about initial states and the universe's quantum nature.

Contribution

It develops a unified theoretical framework using quantum field theory techniques to analyze noise, fluctuation, and decoherence in quantum cosmology, questioning common simplifications.

Findings

Questioning the validity of minisuperspace truncation.

Highlighting the importance of initial conditions.

Connecting chaos and complexity to quantum cosmology.

Abstract

Statistical mechanical concepts and processes such as decoherence, correlation, and dissipation can prove to be of basic importance to understanding some fundamental issues of quantum cosmology and theoretical physics such as the choice of initial states, quantum to classical transition and the emergence of time. Here we summarize our effort in 1) constructing a unified theoretical framework using techniques in interacting quantum field theory such as influence functional and coarse-grained effective action to discuss the interplay of noise, fluctuation, dissipation and decoherence; and 2) illustrating how these concepts when applied to quantum cosmology can alter the conventional views on some basic issues. Two questions we address are 1) the validity of minisuperspace truncation, which is usually assumed without proof in most discussions, and 2) the relevance of specific initial conditions, which is the prevailing view of the past decade. We also mention how some current ideas in chaotic dynamics, dissipative collective dynamics and complexity can alter our view of the quantum nature of the universe.