We study the classical c → ∞ limit of the Virasoro conformal blocks. We point out that the classical limit of the simplest nontrivial null-vector decoupling equation on a sphere leads to the Painlevé VI equation. This gives the explicit representation of generic four-point classical conformal block in terms of the regularized action evaluated on certain solution of the Painlevé VI equation. As a simple consequence, the monodromy problem of the Heun equation is related to the connection problem for the Painlevé VI.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Differential and Algebraic Geometry
- Integrable Field Theories
- Integrable Hierarchies