Axiomatic quantum field theory in curved spacetime

TL;DR

This paper develops a local, covariant axiomatic framework for quantum field theory in curved spacetime, emphasizing the Operator Product Expansion (OPE) as fundamental, and proves key theorems like spin-statistics and PCT in this setting.

Contribution

It introduces a new axiomatic approach based on the OPE for quantum field theory in curved spacetime, generalizing Minkowski space formulations.

Findings

Established axioms for OPE coefficients in curved spacetime

Proved curved spacetime versions of spin-statistics and PCT theorems

Provided a framework for locally covariant quantum field theory

Abstract

The usual formulations of quantum field theory in Minkowski spacetime make crucial use of features--such as Poincare invariance and the existence of a preferred vacuum state--that are very special to Minkowski spacetime. In order to generalize the formulation of quantum field theory to arbitrary globally hyperbolic curved spacetimes, it is essential that the theory be formulated in an entirely local and covariant manner, without assuming the presence of a preferred state. We propose a new framework for quantum field theory, in which the existence of an Operator Product Expansion (OPE) is elevated to a fundamental status, and, in essence, all of the properties of the quantum field theory are determined by its OPE. We provide general axioms for the OPE coefficients of a quantum field theory. These include a local and covariance assumption (implying that the quantum field theory is locally and covariantly constructed from the spacetime metric), a microlocal spectrum condition, an "associativity" condition, and the requirement that the coefficient of the identity in the OPE of the product of a field with its adjoint have positive scaling degree. We prove curved spacetime versions of the spin-statistics theorem and the PCT theorem. Some potentially significant further implications of our new viewpoint on quantum field theory are discussed.