Speaker: Shi Chen (Tokyo U.)
Title: Solitonic symmetry beyond homotopy groups
Abstract: Solitonic symmetry is believed to be classified by homotopy groups, but I will point out a more sophisticated algebraic structure. I shall focus on a concrete QFT, the 4d CP^1 model, and demonstrate that π_3 (CP^1) = Z does not lead to a U(1) 0-form solitonic symmetry. Actually, the invertible 0-form solitonic symmetry is a Z_2 which comes from Ω^spin_3 (CP^1) = Z_2. The complete 0-form solitonic symmetry is a non-invertible symmetry generated by 3d spin TQFTs.
Date & Time: 3:00 PM, Jan 11, 2023.
Video: Link