Conformal blocks, parenthesized braid operad, and $c=1/2$ Virasoro vertex operator algebra (opens in new tab)

We review the construction of a pseudo-braided category structure on the $C_1$-cofinite module category of a vertex operator algebra using conformal blocks and analytic continuation along paths in configuration spaces. In the rational $C_2$-cofinite case, the pseudo-braided category is represented by tensor products and becomes a balanced braided tensor category. We then compute all four-point conformal blocks of the Virasoro vertex operator alg...