By Enrico Pajer
This lecture develops the path-integral description of open quantum systems using the closed time contour. Topics include: - The Schwinger–Keldysh (in-in) formalism, - Doubling of fields and the structure of the closed time path, - In-in Feynman rules and perturbation theory for open systems, retarded, advanced and Keldysh propagators, - Noise, dissipation, and influence functionals, - Constraints from ultraviolet unitarity, locality, and symmetries. The equivalence between operator and path-integral approaches is emphasized, together with the structural constraints imposed by unitarity and symmetries at high energies.
By Enrico Pajer
By Enrico Pajer
By Enrico Pajer
By Enrico Pajer
By Matias Zaldarriaga
By Matias Zaldarriaga
By Raffaele D’Agnolo
By Raffaele D’Agnolo
By Raffaele D’Agnolo
By José Luis Jaramillo
