English

Top-stable degenerations of finite dimensional representations II

Representation Theory 2014-07-11 v1 Rings and Algebras

Abstract

Let Λ\Lambda be a finite dimensional algebra over an algebraically closed field. We exhibit slices of the representation theory of Λ\Lambda that are always classifiable in stringent geometric terms. Namely, we prove that, for any semisimple object TΛ-modT \in \Lambda\text{-mod}, the class of those Λ\Lambda-modules with fixed dimension vector (say d\bf d) and top TT which do not permit any proper top-stable degenerations possesses a fine moduli space. This moduli space, ModuliMaxdT\mathfrak{ModuliMax}^T_{\bf d}, is a projective variety. Despite classifiability up to isomorphism, the targeted collections of modules are representation-theoretically rich: indeed, any projective variety arises as ModuliMaxdT\mathfrak{ModuliMax}^T_{\bf d} for suitable choices of Λ\Lambda, d\bf d, and TT. In tandem, we give a structural characterization of the finite dimensional representations that have no proper top-stable degenerations.

Keywords

Cite

@article{arxiv.1407.2691,
  title  = {Top-stable degenerations of finite dimensional representations II},
  author = {H. Derksen and B. Huisgen-Zimmermann and J. Weyman},
  journal= {arXiv preprint arXiv:1407.2691},
  year   = {2014}
}