  Edge theories of symmetry-protected topological phases are well-known to
possess global symmetry anomalies. In this work we focus on two-dimensional
bosonic phases protected by an on-site symmetry and analyse the corresponding
edge anomalies in more detail. Physical interpretations of the anomaly in terms
of an obstruction to orbifolding and constructing symmetry-preserving
boundaries are connected to the cohomology classification of symmetry-protected
phases in two dimensions. Using the tensor network and matrix product state
formalism we numerically illustrate our arguments and discuss computational
detection schemes to identify symmetry-protected order in a ground state wave
function.
