| Abstract: |
We find that multiple vertex operator algebras (VOAs) can arise from a single 4d N=2 superconformal field theory (SCFT). The connection is given by the BPS monodromy operator M, which is a wall-crossing invariant quantity that captures the BPS spectrum on the Coulomb branch. We find that the trace of the multiple powers of the monodromy operator Tr M^N produces the vacuum characters of a VOA for each N. In particular, we realize unitary VOAs of the Deligne-Cvitanović exceptional series from Argyres-Douglas theories. We also find the modular invariant characters of the `intermediate vertex subalgebra' E_{7.5} at level 1. Our analysis allows us to construct 3d N=2 gauge theories that flow to N=4 SCFTs in the IR, which gives rise to the topological field theories realizing the VOAs with these characters. |
