English

Irreducible cuspidal $\mathfrak{sl}_{n+1}$-modules from finite-dimensional modules over the minimal nilpotent finite $W$-algebra

Representation Theory 2026-01-08 v2 Rings and Algebras

Abstract

A weight sln+1\mathfrak{sl}_{n+1}-module with finite-dimensional weight spaces is called a cuspidal module, if every root vector of sln+1\mathfrak{sl}_{n+1} acts injectively on it. In \cite{LL}, it has been shown that any block with a generalized central character of the cuspidal sln+1\mathfrak{sl}_{n+1}-module category is equivalent to a block of the category of finite-dimensional modules over the minimal nilpotent finite WW-algebra W(e)W(e) for sln+1\mathfrak{sl}_{n+1}. In this paper, using a centralizer realization of W(e)W(e) and an explicit embedding W(e)U(gln)W(e)\rightarrow U(\mathfrak{gl}_n), we show that every finite-dimensional irreducible W(e)W(e)-module is isomorphic to an irreducible W(e)W(e)-quotient module of some finite-dimensional irreducible gln\mathfrak{gl}_n-module. As an application, we can give very explicit realizations of all irreducible cuspidal sln+1\mathfrak{sl}_{n+1}-modules using finite-dimensional irreducible gln\mathfrak{gl}_n-modules, avoiding using the twisted localization method and the coherent family introduced in \cite{M}.

Keywords

Cite

@article{arxiv.2505.19417,
  title  = {Irreducible cuspidal $\mathfrak{sl}_{n+1}$-modules from finite-dimensional modules over the minimal nilpotent finite $W$-algebra},
  author = {Genqiang Liu and Mingjie Li},
  journal= {arXiv preprint arXiv:2505.19417},
  year   = {2026}
}