Quantum field theory with indefinite causal structure

TL;DR

This paper introduces a novel theoretical framework for quantum field theory that accounts for indefinite causal structures of spacetime, aiming to better understand quantum gravitational effects on phenomena like black hole thermodynamics.

Contribution

It develops a model-independent theory for quantum fields in spacetimes with indefinite causal structure, revealing universal features of quantum spacetime beyond specific microscopic models.

Findings

Universal features of quantum spacetime identified

Framework applicable to various quantum gravity models

Enhanced understanding of quantum gravitational effects on QFT

Abstract

Quantum field theory (QFT) in classical spacetime has revealed interesting and puzzling aspects about gravitational systems, in particular black hole thermodynamics and its information processing. Although quantum gravitational effects may be relevant for a better understanding of these topics, a commonly accepted framework for studying QFT with quantum gravitational effects is missing. We present a theory for studying quantum fields in the presence of quantum indefinite causal structure. This theory incorporates quantum properties of spacetime causal structure in a model independent way, and exposes universal features of quantum spacetime which are independent of the details about its microscopic degrees of freedom (strings, loops, causal sets...).