{ "id": "1702.06333", "version": "v1", "published": "2017-02-21T11:25:32.000Z", "updated": "2017-02-21T11:25:32.000Z", "title": "Cohomology and extensions of ordered groupoids", "authors": [ "B. O. Bainson", "N. D. Gilbert" ], "comment": "18 pages", "categories": [ "math.GR" ], "abstract": "We adapt and generalise results of Loganathan on the cohomology of inverse semigroups to the cohomology of ordered groupoids. We then derive a five-term exact sequence in cohomology from an extension of ordered groupoids, and show that this sequence leads to a classification of extensions by a second cohomology group. Our methods use structural ideas in cohomology as far as possible, rather than computation with cocycles.", "revisions": [ { "version": "v1", "updated": "2017-02-21T11:25:32.000Z" } ], "analyses": { "subjects": [ "20L05" ], "keywords": [ "ordered groupoids", "second cohomology group", "five-term exact sequence", "structural ideas", "inverse semigroups" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }