{ "id": "1911.00590", "version": "v1", "published": "2019-11-01T21:06:24.000Z", "updated": "2019-11-01T21:06:24.000Z", "title": "Graph inverse semigroups and Leavitt path algebras", "authors": [ "John Meakin", "Zhengpan Wang" ], "comment": "39 pages", "categories": [ "math.GR" ], "abstract": "We study two classes of inverse semigroups built from directed graphs, namely graph inverse semigroups and a new class of semigroups that we refer to as Leavitt inverse semigroups. These semigroups are closely related to graph $C^*$-algebras and Leavitt path algebras. We provide a topological characterization of the universal groups of the local submonoids of these inverse semigroups. We study the relationship between the graph inverse semigroups of two graphs when there is a directed immersion between the graphs. We describe the structure of graphs that admit a directed cover or directed immersion into a circle and we provide structural information about graph inverse semigroups of finite graphs that admit a directed cover onto a bouquet of circles. We also find necessary and sufficient conditions for a homomorphic image of a graph inverse semigroup to be another graph inverse semigroup. We find a presentation for the Leavitt inverse semigroup of a graph in terms of generators and relations. We describe the structure of the Leavitt inverse semigroup and the Leavitt path algebra of a graph that admits a directed immersion into a circle. We show that two graphs that have isomorphic Leavitt inverse semigroups have isomorphic Leavitt path algebras and we classify graphs that have isomorphic Leavitt inverse semigroups. As a consequence, we show that Leavitt path algebras are $0$-retracts of certain matrix algebras.", "revisions": [ { "version": "v1", "updated": "2019-11-01T21:06:24.000Z" } ], "analyses": { "subjects": [ "20M18", "05C20" ], "keywords": [ "graph inverse semigroup", "isomorphic leavitt inverse semigroups", "directed immersion", "isomorphic leavitt path algebras", "directed cover" ], "note": { "typesetting": "TeX", "pages": 39, "language": "en", "license": "arXiv", "status": "editable" } } }