{ "id": "1508.04353", "version": "v1", "published": "2015-08-18T15:30:15.000Z", "updated": "2015-08-18T15:30:15.000Z", "title": "Irreducible morphisms and locally finite dimensional representations", "authors": [ "Charles Paquette" ], "comment": "16 pages, 1 figure", "categories": [ "math.RT" ], "abstract": "Let $\\mathcal{A}$ be a Hom-finite additive Krull-Schmidt $k$-category where $k$ is an algebraically closed field. Let ${\\rm mod} \\mathcal{A}$ denote the category of locally finite dimensional $\\mathcal{A}$-modules, that is, the category of covariant functors $\\mathcal{A} \\to {\\rm mod} k$. We prove that an irreducible monomorphism in ${\\rm mod} \\mathcal{A}$ has a finitely generated cokernel, and that an irreducible epimorphism in ${\\rm mod} \\mathcal{A}$ has a finitely co-generated kernel. Using this, we get that an almost split sequence in ${\\rm mod} \\mathcal{A}$ has to start with a finitely co-presented module and end with a finitely presented one. Finally, we apply our results in the study of ${\\rm rep}(Q)$, the category of locally finite dimensional representations of a strongly locally finite quiver. We describe all possible shapes of the Auslander-Reiten quiver of ${\\rm rep}(Q)$.", "revisions": [ { "version": "v1", "updated": "2015-08-18T15:30:15.000Z" } ], "analyses": { "subjects": [ "16G20", "16G70", "16D90" ], "keywords": [ "locally finite dimensional representations", "irreducible morphisms", "hom-finite additive krull-schmidt", "auslander-reiten quiver", "strongly locally finite quiver" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }