The characteristic polynomials of imprimitive groups and affine Coxeter groups
Chenyue Feng, Shoumin Liu, Xumin Wang
TL;DR
This work develops a generator-aware framework for characteristic polynomials of finite and affine complex groups, showing that for imprimitive groups $G(r,1,n)$ and their products, as well as for irreducible affine Coxeter groups $\tilde{W}$ and the imprimitive groups $G(r,p,n)$, the characteristic polynomial $d(S,\rho)$ uniquely determines the representation $\rho$ up to isomorphism. Central to the method is the construction of a canonical word reduction via echelon form and admissible transformations, which allows comparing characters through word signatures and then deducing full representation data from $d(S,\rho)$. A general semidirect-product abelian-subgroup framework (Theorem 4.4) underpins the affine case, enabling analogous conclusions by combining finite-part conjugacy data with a translation lattice. The results provide a bridge between algebraic geometry and representation theory by linking determinant-based invariants to the complete representation theory of these groups, with concrete implications for $G(r,p,n)$ and affine extensions.
Abstract
In this paper, we will seek appropriate generators to define the characteristic polynomials of $G(r,1,n)$, and prove that for every finite dimensional representation of $G(r,1,n)$, the characteristic polynomial of $G(r,1,n)$ determines the character of this representation. Furthermore, the same conclusion holds for affine Coxeter groups \(\widetilde{W}\) and $G(r,p,n)$.
