MS Seminar (Mathematics - String Theory)

Speaker: Kazuya Yonekura (Tohoku U)
Title: Constraints on the topology of Type IIB string theory
Date (JST): Tue, Jun 18, 2024, 13:30 - 15:00
Place: Seminar Room A
Abstract: We discuss some topological constraints on Type IIB string theory that cannot be described by elementary characteristic classes. Anomaly cancellation of the worldvolume theory of a D3-brane requires a shifted Dirac quantization condition of the Ramond-Ramond 5-form flux. However, the required shift is sometimes inconsistent depending on the topology of spacetime backgrounds. The obstruction to the existence of a shifted quantization is described by a degree-6 cohomology class whose definition involves spin structure of spacetime manifolds. The cohomology class is interpreted as a background D3-charge, and the Gauss law constraint requires inclusion of additional D3-branes to cancel it.