PIRSA:20010023

Video URL

https://pirsa.org/20010023

A deformation invariant of 1+1D SQFTs

Johnson-Freyd, T. (2020). A deformation invariant of 1+1D SQFTs. Perimeter Institute for Theoretical Physics. https://pirsa.org/20010023

Johnson-Freyd, Theo. A deformation invariant of 1+1D SQFTs. Perimeter Institute for Theoretical Physics, Jan. 14, 2020, https://pirsa.org/20010023 

          @misc{ scivideos_PIRSA:20010023,
            doi = {10.48660/20010023},
            url = {https://pirsa.org/20010023},
            author = {Johnson-Freyd, Theo},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {A deformation invariant of 1+1D SQFTs},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2020},
            month = {jan},
            note = {PIRSA:20010023 see, \url{https://scivideos.org/pirsa/20010023}}
          }

Theo Johnson-Freyd Dalhousie University

Talk numberPIRSA:20010023
DOI10.48660/20010023
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

The elliptic genus is a powerful deformation invariant of 1+1D SQFTs: if it is nonzero, then it protects the SQFT from admitting a deformation to one with spontaneous supersymmetry breaking. I will describe a "secondary" invariant, defined in terms of mock modularity, that goes beyond the elliptic genus, protecting SQFTs with vanishing elliptic genus. The existence of this invariant supports the hypothesis that the space of minimally supersymmetric 1+1D SQFTs provides a geometric model for universal elliptic cohomology. Based on joint works with D. Gaiotto and E. Witten.