2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73349Let $A$ be a sheaf of Azumaya algebras over a Noetherian base $S$. In this paper we describe using generalized Severi-Brauer varieties, a quasi-projective moduli space parametrizing sheaves of ètale subalgebras of $A$. In the case that $S$ is the spectrum of a field, we study the geometry of this moduli space, and show that in certain cases it is a rational variety.8 pagesRings and AlgebrasAlgebraic Geometry16H05; 16K20; 14M15; 14M20text