General Linear and Symplectic Nilpotent Orbit Varieties

Abstract: The condition of nilpotency is studied in the general linear Lie algebra $\mathfrak{gl}{n}(\mathbb{K})$ and the symplectic Lie algebra $\mathfrak{sp}{2m}(\mathbb{K})$ over an algebraically closed field of characteristic 0. In particular, the conjugacy class of nilpotent matrices is described through nilpotent orbit varieties $\mathcal{O}{\lambda}$ and an algorithm is provided for computing the closure $\overline{\mathcal{O}{\lambda}} \cong \text{Spec}\left(\mathbb{K}[X]\big/J_{\lambda}\right).$ We provide new generators for the ideal $J_{\lambda}$ defining the affine variety $\overline{\mathcal{O}{\lambda}}$ which show that the generators provided in [J.Weyman - "The equations of conjugacy classes of nilpotent matrices", 1989] are not minimal. Furthermore, we conjecture the existence of local weak N\'{e}ron models for nilpotent orbit varieties based on bounding $p$ in the polynomial ring with p-adic integer coefficients for which the equations defining $\mathcal{O}{\lambda}$ can embed.