Speaker: Rajath Radhakrishnan (ICTP, Trieste)
Title: Constraints on non-invertible symmetries in 2+1D
Abstract: In this talk, I will discuss some constraints on non-invertible symmetries implemented by surface operators in 2+1D QFTs. I will first consider abelian TQFTs and argue that non-invertible surface operators exist if and only if there are bosonic line operators. I will then discuss an extension of this result to non-abelian TQFTs. This implies that all condensation defects are invertible in a TQFT without bosonic line operators. I will give an independent argument for this result using higher-gauging of line operators. Finally, I will discuss some implications for general 2+1D QFTs. This talk is based on the paper https://arxiv.org/abs/2309.15181 with Matthew Buican.