WICK ROTATION AND THE POSITIVITY OF ENERGY IN QUANTUM FIELD THEORY

We propose a new axiom system for unitary quantum field theories on curved space-time backgrounds, by postulating that the partition function and the correlators extend analytically to a certain domain of complex-valued metrics. Ordinary Riemannian metrics are contained in the allowable domain, while Lorentzian metrics lie on its boundary.

Automated summary

The proposed axiom system assumes the extension of partition function and correlators to a domain of complex-valued metrics; ordinary Riemannian metrics are within this domain, while Lorentzian metrics lie on its boundary.