PIRSA:19100043

Strings on the Keldysh Contour

APA

Mogni, C. (2019). Strings on the Keldysh Contour. Perimeter Institute. https://pirsa.org/19100043

MLA

Mogni, Christopher. Strings on the Keldysh Contour. Perimeter Institute, Oct. 15, 2019, https://pirsa.org/19100043

BibTex

          @misc{ pirsa_19100043,
            doi = {10.48660/19100043},
            url = {https://pirsa.org/19100043},
            author = {Mogni, Christopher},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Strings on the Keldysh Contour},
            publisher = {Perimeter Institute},
            year = {2019},
            month = {oct},
            note = {PIRSA:19100043 see, \url{https://pirsa.org}}
          }
          

Christopher Mogni University of California

Abstract

There is a fundamental tension between what string theory computes (S-matrix elements) and what you can compute in QFT on a time-dependent backgrounds (real time operator expectation values). The prescription for computing time dependent expectation values in QFT involves a path integral defined on a closed time path, known as the Keldysh contour. In this talk, we'll discuss how a worldsheet formulation of string theory must perceive the Keldysh contour and how this modifies critical string theory at tree level in the string coupling.