From Heun to Painlevé on Sasaki-Einstein Spaces and Their Confluent Limits

The aim of this paper is to study the effect of isomonodromic deformations of the evolution of scalar fields in Sasaki-Einstein spaces in the context of holography. Here we analyze the monodromy data of the general Heun equation, resulting from a scalar on Y${}^{p,q}$, thus obtaining the corresponding Painlevé VI equation. Furthermore we have considered limits leading to a coalescence of singularities, which in turn transform the original Painlevé VI equation, to one of lower rank. The confluent limits we have considered are Y${}^{p,p}$, T${}^{1,1}\mathrm{/}{\mathbb{Z}}_2$ and Y${}^{\mathrm{\infty },q}$.