The anomaly that was not meant IIB

Understand

Type IIB supergravity enjoys a discrete non-Abelian duality group, which has potential quantum anomalies.

• In this paper we explicitly compute these, and present the bordism group that controls them, modulo some physically motivated assumptions.
• Quite surprisingly, we find that they do not vanish, which naively would signal an inconsistency of F-theory.
• Remarkably, a subtle modification of the standard 10d Chern-Simons term cancels these anomalies, a fact which relies on the ***specific*** field content of type IIB supergravity.