A new way to construct 1-singular Gelfand-Tsetlin modules

Abstract

We present a simplified way to construct the Gelfand-Tsetlin modules over $\mathfrak{gl}(n,\mathbb{C})$ related to a $1$-singular GT-tableau defined by Futorny, Grantcharov and Ramirez. We begin by reframing the classical construction of generic Gelfand-Tsetlin modules found by Drozd, Futorny and Ovsienki, showing that they form a flat family over generic points of ${\mathbb{C}}^{\left(\genfrac{}{}{0ex}{}{n}{2}\right)}$. We then show that this family can be extended to a flat family over a variety including generic points and $1$-singular points for a fixed singular pair of entries. The $1$-singular modules are precisely the fibers over these points.

12 pages. Sent for publication in Algebra and Discrete Mathematics