Constraining boundary conditions in nonrational CFTs
Abstract
We revisit the question of conformal boundary conditions in the compact free boson CFT in two dimensions. Besides the well-known Neumann and Dirichlet cases, there is an additional proposed one-parameter family of boundary states when the radius is an irrational multiple of the self-dual radius. These additional states have a continuous open string spectrum, and we give an explicit formula for the density of states. We also discuss several pathologies of these states, including the possible violation of the cluster condition, and that they have a divergent g function.
Fields of Study & Subjects
Algebraic structures and combinatorial models
Advanced Operator Algebra Research
Spectral Theory in Mathematical Physics
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Volume
- 113
- Issue
- 10
- Publication date
- 30 April 2026
- Language
- EN