Extended affine Weyl groups of BCD type, Frobenius manifolds and their Landau-Ginzburg superpotentials

Abstract

For the root systems of type $B_l, C_l$ and $D_l$, we generalize the result of \cite{DZ1998} by showing the existence of Frobenius manifold structures on the orbit spaces of the extended affine Weyl groups that correspond to any vertex of the Dynkin diagram instead of a particular choice made in \cite{DZ1998}. It also depends on certain additional data. We also construct LG superpotentials for these Frobenius manifold structures.