We study properties of boundary conditions (BCs) in theories with categorical (or non-invertible) symmetries. We describe how the transformation properties, or (generalized) charges, of BCs are captured by topological BCs of Symmetry Topological Field Theory (SymTFT), which is a topological field theory in one higher spacetime dimension. As an application of the SymTFT chracterization, we discuss the symmetry properties of boundary conditions for (1+1)d gapped and gapless phases. We provide a number of concrete examples in spacetime dimensions d=2,3. We furthermore expand the lattice description for (1+1)d anyon chains with categorical symmetries to include boundary conditions carrying arbitrary 1-charges under the symmetry.
@article{arxiv.2409.02166,
title = {Boundary SymTFT},
author = {Lakshya Bhardwaj and Christian Copetti and Daniel Pajer and Sakura Schafer-Nameki},
journal= {arXiv preprint arXiv:2409.02166},
year = {2025}
}