Backfiring Bosonisation in Diverse DimensionsConfirmed

by Philip Boyle Smith (International School for Advanced Studies (SISSA), Trieste)

Friday May 15, 2026, 2:30 PM → 4:00 PM America/Toronto

PI/4-405 - Bob Room (Perimeter Institute for Theoretical Physics)

Various operations on two-dimensional quantum field theories such as the GSO projection and various dualities involve a sum over spin structures. This talk will discuss a subtle mod-16 anomaly in the spin structure, extending the usual mod-8 anomaly of fermion parity, which can obstruct this sum. As such one must account for this anomaly to define these operations properly or face surprising consequences. We will see how this phenomenon is captured cleanly by homotopy theory, specifically the non-vanishing cohomology of a sequence of cobordism groups. From there, we will discuss applications in diverse dimensions and with additional symmetries, and the corresponding SymTFT.