We will introduce Hecke kernels according to Kontsevich and show how to construct congruence $D2$ differential equations via Hecke correspondences in practice.
Links:
[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/node/3444
[3] http://www.mpim-bonn.mpg.de/node/4343