Abstract:The moduli spaces of points on n-spheres carry natural actions of braid groups. For n=0, 1, and 3, we prove that these symmetries extend to actions of mapping class groups of certain positive genus surfaces, through exceptional isomorphisms with certain moduli of local systems. Moreover, the isomorphisms map the Coxeter invariants of points on spheres to the boundary monodromy of the ...
Speaker:Xiaomeng Xu 徐晓濛 (PKU)Time:9:50-11:50am on Nov. 3, 17, 24, December 1, 2025Venue:A513, Shuangqing Complex Building AAbstract:Lecture 1. An introduction to the Stokes phenomenon and isomonodromy deformation. The first lecture gives an introduction to the Stokes matrices of a linear system of meromorphic ordinary differential equations, and the associated nonlinear isomonodromy defor...