{ "id": "2005.01787", "version": "v1", "published": "2020-05-04T18:52:44.000Z", "updated": "2020-05-04T18:52:44.000Z", "title": "Oriented Matroids from Triangulations of Products of Simplices", "authors": [ "Marcel Celaya", "Georg Loho", "Chi Ho Yuen" ], "comment": "51 pages, 15 Figures", "categories": [ "math.CO", "math.GT", "math.OC" ], "abstract": "We introduce a construction of oriented matroids from a triangulation of a product of two simplices. For this, we use the structure of such a triangulation in terms of polyhedral matching fields. The oriented matroid is composed of compatible chirotopes on the cells in a matroid subdivision of the hypersimplex, which might be of independent interest. In particular, we generalize this using the language of matroids over hyperfields, which gives a new approach to construct matroids over hyperfields. Using the polyhedral structure, we derive a topological representation of the oriented matroid. This relies on a variant of Viro's patchworking and insights on the structure of tropical oriented matroids. A recurring theme in our work is that various tropical constructions can be extended beyond tropicalization with new formulations and proof methods.", "revisions": [ { "version": "v1", "updated": "2020-05-04T18:52:44.000Z" } ], "analyses": { "subjects": [ "52C40", "05E45", "12K99", "14T05", "52B40", "52C30", "57N60", "57Q99" ], "keywords": [ "oriented matroid", "triangulation", "polyhedral matching fields", "matroid subdivision", "independent interest" ], "note": { "typesetting": "TeX", "pages": 51, "language": "en", "license": "arXiv", "status": "editable" } } }