IAS HET Seminar | Miguel Montero, Harvard University | "The anomaly that was not meant IIB" | Wolfensohn Hall & via Zoom

Mon, Sep 27, 2021, 2:30 pm
Wolfensohn Hall & via Zoom

This seminar will be presented in-person in Wolfensohn Hall at the IAS and on Zoom.

For contact-tracing purposes all attendees must register for this seminar: 

All in-person attendees must be fully vaccinated and masks are required in all indoor spaces (except while actively eating). Additionally, all off-campus attendees are required to upload proof of vaccination via the IAS CrowdPass App 

Abstract: Type IIB supergravity famously has a discrete duality group, which is an exact symmetry of the full type IIB string theory. This symmetry has potential quantum anomalies, which could render the theory inconsistent. In this talk I will describe how we computed these anomalies in recent work, and show they are nonvanishing, but remarkably, they can be cancelled by a subtle modification of the IIB Chern-Simons term in what amounts to a new variant of the Green-Schwarz mechanism. This only happens because of some cancellations that depend on the precise details of the IIB supergravity spectrum. I will also describe alternative ways to cancel this anomaly, presenting variant versions of IIB string theory which have the same IIB supergravity as the low-energy limit, but which differ at the nonperturbative level. These theories may or may not be in the Swampland.