Recent works in quantum gravity, motivated by the “factorization problem” and “baby universes,” have considered sums over bordisms with fixed boundaries in topological quantum field theory (TQFT). We discuss this construction and observe a curious splitting formula for the total amplitude.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- 2D Gravity
- Field Theories in Lower Dimensions
- Matrix Models
- Topological Field Theories