Partition function (quantum field theory)

Quantum mechanics

Function (biology)

Theoretical physics

Pure mathematics

Mathematical physics

Biology

Boundary (topology)

Quantum field theory

Field (mathematics)

Operating system

Computer science

Rotation (mathematics)

Evolutionary biology

Physics

Mathematics

Political science

Axiom

Unitary state

Domain (mathematical analysis)

Mathematical analysis

Geometry

Quantum

Space (punctuation)

The Quarterly Journal of Mathematics

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.

Wick Rotation and the Positivity of Energy in Quantum Field Theory