The anomaly that was not meant IIB

Abstract

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. We also discover other ways to cancel this anomaly, via a topological analog of the Green-Schwarz mechanism. These alternative type IIB theories have the same low energy supergravity limit as ordinary type IIB, but a different spectrum of extended objects. They could either be part of the Swampland, or connect to the standard theory via domain walls.

40 pages + appendices, 4 figures, 331776 bordism classes. v2: Added references, expanded discussion on quadratic refinement

References in corpus (16)

• Symmetries and Strings in Field Theory and Gravity
• The String Landscape and the Swampland
• Lectures on F-theory compactifications and model building
• Les Houches Lectures on Constructing String Vacua
• Physics of String Flux Compactifications
• Symmetric-Gapped Surface States of Fractional Topological Insulators
• Anomaly Obstructions to Symmetry Preserving Gapped Phases
• 8d Supergravity, Reconstruction of Internal Geometry and the Swampland
• 8d gauge anomalies and the topological Green-Schwarz mechanism
• On the Swampland Cobordism Conjecture and Non-Abelian Duality Groups
• Topological duality twist and brane instantons in F-theory
• The algebra of anomaly interplay
• Duality group actions on fermions
• Six-dimensional Origin of $\mathcal{N}=4$ SYM with Duality Defects
• Gauge Enhanced Quantum Criticality Beyond the Standard Model
• Discrete anomalies in supergravity and consistency of string backgrounds

Cited by in corpus (9)

• Higher Symmetries of 5d Orbifold SCFTs
• Global anomalies in 8d supergravity
• New Supersymmetric String Theories from Discrete Theta Angles
• Dimensional Reduction of Cobordism and K-theory
• Looking for structure in the cobordism conjecture
• The discrete Green-Schwarz mechanism in 6D F-Theory and Elliptic Genera of Non-Critical Strings
• The Characteristic Dimension of Four-dimensional $\mathcal{N}=2$ SCFTs
• What bordism-theoretic anomaly cancellation can do for U
• Symmetry TFTs from String Theory