Speaker
Description
Non-integrable quantum many-body systems are generally expected to thermalize. That is, local observables relax to values predicted by a thermal ensemble constrained by the conserved quantities. However, in recent years, a growing number of exceptions have been identified, including many lattice Hamiltonians with gauge symmetry. In this talk, based on arXiv:2604.15820, I will outline how several of these exceptions can be explained by unresolved generalized symmetries. Once the corresponding conserved quantities, beyond conventional global charges, are taken into account, the dynamics can again be accurately predicted by a thermal ensemble. I will discuss partial isometries, which act as symmetry operators only on a subspace of the Hilbert space and provide a natural extension of conventional symmetries. In the studied lattice gauge theory Hamiltonians, partial isometries describe symmetries that exist only within specific superselection or winding sectors, thereby providing a framework for understanding novel anomalous out-of-equilibrium dynamics in quantum many-body systems.