Editing Moduli space (section)

===Moduli of vector bundles===
Another important moduli problem is to understand the geometry of (various substacks of) the moduli stack Vect<sub>''n''</sub>(''X'') of rank ''n'' [[vector bundle]]s on a fixed [[algebraic variety]] ''X''.<ref>{{Cite web|title=Algebraic Stacks and Moduli of Vector Bundles|url=https://impa.br/wp-content/uploads/2017/04/PM_36.pdf}}</ref> This stack has been most studied when ''X'' is one-dimensional, and especially when n equals one.  In this case, the coarse moduli space is the [[Picard scheme]], which like the moduli space of curves, was studied before stacks were invented. When the bundles have rank 1 and degree zero, the study of coarse moduli space is the study of the [[Jacobian variety]].

In applications to [[physics]], the number of moduli of vector bundles and the closely related problem of the number of moduli of [[Fiber bundle|principal G-bundles]] has been found to be significant in [[gauge theory]].{{citation needed|date=June 2013}}