Title: Kramers-Wannier-like duality defects in higher dimensions Abstract: I will introduce a class of non-invertible topological defects in (3 + 1)d gauge theories whose fusion rules are the higher-dimensional analogs of those of the Kramers-Wannier defect in the (1 + 1)d critical Ising model. As in the lower-dimensional case, the presence of such non-invertible defects implies self-duality […]

Speaker: Yuji Tachikawa (Kavli IPMU, U Tokyo) Title: On the absence of global anomalies of heterotic string theories Abstract: Superstring theory as we know it started from the discovery by Green and Schwarz in 1984 that the perturbative anomalies of heterotic strings miraculously cancel. But the cancellation of global anomalies of heterotic strings remained an open […]

Speaker: Mohamed Anber (Durham University) Title: The global structure of the Standard Model and new nonperturbative processes Abstract: It is well-established that the Standard Model (SM) of particle physics is based on su(3)Xsu(2)Xu(1) Lie-algebra. What is less appreciated, however, is that SM accommodates a Z_6 1-form global symmetry.  Gauging this symmetry, or a subgroup of it, changes […]

Speaker: Petr Hořava (UC Berkeley) Title: Topological Quantum Gravity and the Ricci Flow – Part I Abstract: In this sequence of talks, I will describe our work with Alexander Frenkel and Stephen Randall, in which we presented a novel topological quantum gravity, relating three previously unrelated fields:  Topological quantum field theories (of the cohomological type), the […]

Speaker: Andrea Grigoletto (SISSA & INFN) Title: Spin-cobordisms, surgeries and fermionic modular bootstrap Abstract: ‘tHooft anomalies of anomalous systems can be described via anomaly inflow by invertible theories living in one dimension higher. Thanks to this it is possible to provide a general method to determine modular transformations of anomalous 2d fermionic CFTs with general discrete symmetry […]

Abstract: In this sequence of talks, I will describe our work with Alexander Frenkel and Stephen Randall, in which we presented a novel topological quantum gravity, relating three previously unrelated fields:  Topological quantum field theories (of the cohomological type), the theory of Ricci flows on Riemannian manifolds, and nonrelativistic quantum gravity.  The remarkable richness of […]

Abstract: Three-dimensional (3d) gapped topological phases with fractional excitations are divided into two subclasses: One has topological order with point-like and loop-like excitations fully mobile in the 3d space, and the other has fracton order with point-like excitations constrained in lower-dimensional subspaces. These exotic phases are often studied by exactly solvable Hamiltonians made of commuting projectors, […]

Abstract: We construct infinitely many new exactly solvable local commuting projector lattice Hamiltonian models for general bosonic beyond group cohomology invertible topological phases of order two and four in any spacetime dimensions, whose boundaries are characterized by gravitational anomalies. Examples include the beyond group cohomology invertible phase “w2w3” in (4+1)D that has an anomalous boundary topological […]

Abstract: In this talk we will discuss the interaction between magnetic monopoles and massless fermions. In the 1980’s Callan and Rubakov showed that in the simplest example and that fermion-monopole interactions catalyze proton decay in GUT completions of the standard model. Here we will explain how fermions in general representations interact with general spherically symmetric monopoles […]