Non-commutative Grassmann variety as a moduli space
Yujiro Kawamata
TL;DR
This work introduces a non-commutative analogue of the Grassmannian $G(2,4)$ by constructing an NC moduli space $NCG(2,4)$ as an NC scheme built from gluing local NC charts. The core idea is to arrange local models $R_ u$ whose abelianizations recover the classical open sets and whose completions at closed points realize semi-universal NC deformations of the corresponding subspaces, while a universal NC deformation family is globally parameterized. The paper provides explicit gluing data for the case $(m,n)=(2,4)$, showing how overlaps and localization behave to ensure a coherent global moduli space. This construction highlights how NC deformations can form a global moduli-theoretic object that extends classical Grassmann geometry, albeit with potential non-Noetherian behavior and mixed commutativity across charts.
Abstract
We construct a non-commutative version of the Grassmann variety $G(2,4)$ as a non-commutative moduli space of linear subspaces in a projective space.
