Olivetti Club
Given a finite group, the number of conjugacy classes is as the same as the number of irreducible representations from character theory but we never know how to correspond them. However, for symmetric group, we can and people usually do it in a combinatorial way. I will talk about a geometric approach to construct these irreducible representations rather than a combinatorial one. This approach is called Springer correspondence, which is one of the cornerstones of geometric representation theory. Each irreducible representation can be realized as the top dimensional Borel-Moore Homology of a fiber of the Springer resolution with an action supplied by the convolution of Borel-Moore Homology. The idea of convolution of Borel-Moore Homology can also be applied to other geometric objects so that we can get other kinds of representations. I will only assume some basic knowledge of representation theory, algebraic topology and manifold theory.