{ "id": "1612.06593", "version": "v1", "published": "2016-12-20T10:28:56.000Z", "updated": "2016-12-20T10:28:56.000Z", "title": "Group actions on quiver varieties and applications", "authors": [ "Victoria Hoskins", "Florent Schaffhauser" ], "categories": [ "math.AG" ], "abstract": "We study two types of actions on moduli spaces of quiver representations over a field $k$ and we decompose their fixed loci using group cohomology. First, for a perfect field $k$, we study the action of the absolute Galois group of $k$ on the $\\overline{k}$-valued points of this quiver moduli space; the fixed locus is the set of $k$-rational points and we obtain a decomposition of this fixed locus indexed by elements in the Brauer group of $k$. Second, we study algebraic actions of finite groups of quiver automorphisms on these moduli spaces; the fixed locus is decomposed using group cohomology and we give a modular interpretation of each component. As an application, we construct branes in hyperk\\\"ahler quiver varieties, as fixed loci of such actions.", "revisions": [ { "version": "v1", "updated": "2016-12-20T10:28:56.000Z" } ], "analyses": { "subjects": [ "14D20", "14L24" ], "keywords": [ "quiver varieties", "fixed locus", "group actions", "application", "group cohomology" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }