Towards a Relativistic KMS Condition

TL;DR

This paper demonstrates that in relativistic quantum field theory, thermal correlation functions exhibit enhanced analyticity properties that extend the traditional KMS-condition, enabling a Lorentz-covariant formulation involving all space-time variables.

Contribution

It introduces a Lorentz-covariant formulation of the KMS-condition based on stronger analyticity properties of thermal correlators in relativistic QFT.

Findings

Thermal correlation functions have enhanced analyticity properties.

These properties are linked to the relativistic spectrum condition.

A Lorentz-covariant KMS-condition is formulated.

Abstract

It is shown that, under quite general conditions, thermal correlation functions in relativistic quantum field theory have stronger analyticity properties in configuration space than those imposed by the KMS-condition. These analyticity properties may be understood as a remnant of the relativistic spectrum condition in the vacuum sector and lead to a Lorentz-covariant formulation of the KMS-condition involving all space-time variables.