Schwinger-Keldysh superspace in quantum mechanics

Understand

We examine, in a quantum mechanical setting, the Hilbert space representation of the BRST symmetry associated with Schwinger-Keldysh path integrals.

• This structure had been postulated to encode important constraints on influence functionals in coarse-grained systems with dissipation, or in open quantum systems.
• Operationally, this entails uplifting the standard Schwinger-Keldysh two-copy formalism into superspace by appending BRST ghost degrees of freedom.
• These statements were previously argued at the level of the correlation functions.