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NHETC Seminar - A deformation invariant of 2D SQFTs

Date and Time: Tuesday, February 25, 2020, 03:00pm - 04:00pm
Location: 385E

NHETC Seminar

Theo Johnson-Freyd (Perimeter Institute)

A deformation invariant of 2D SQFTs

Abstract: The elliptic genus is a powerful deformation invariant of 2D 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 2D SQFTs provides a geometric model for universal elliptic cohomology.

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