Causal signal transmission by quantum fields. IV: The causal Wick theorem

Abstract

Wick's theorem in the Schwinger-Perel-Keldysh closed-time-loop formalism is written in a form where the place of contractions is taken by the linear response function of the field. This result demonstrates that the physical information supplied by Wick's theorem for operators is propagation of the free field in space and time.

arXiv commentFinal version, to appear in Phys Rev D

References in corpus (4)

• Causal signal transmission by quantum fields. II. Quantum-statistical response of interacting bosons
• Causal signal transmission by quantum fields. I. Response of the harmonic oscillator
• Finite Temperature Retarded and Advanced Fields
• Thermal Properties of Interacting Bose Fields and Imaginary-Time Stochastic Differential Equations

Cited by in corpus (2)

• Quantum Thermodynamic Uncertainty Relations, Generalized Current Fluctuations and Nonequilibrium Fluctuation-Dissipation Inequalities
• Quantum theory of an electromagnetic observer: classically behaving macroscopic systems and emergence of classical world in quantum electrodynamics