{ "id": "2102.05899", "version": "v1", "published": "2021-02-11T09:08:20.000Z", "updated": "2021-02-11T09:08:20.000Z", "title": "A complexity of compact 3-manifold via immersed surfaces", "authors": [ "Gennaro Amendola" ], "comment": "19 pages, 11 figures, 1 table. arXiv admin note: substantial text overlap with arXiv:0804.0695", "categories": [ "math.GT" ], "abstract": "We define an invariant, which we call surface-complexity, of compact 3-manifolds by means of Dehn surfaces. The surface-complexity is a natural number measuring how much the manifold is complicated. We prove that it fulfils interesting properties: it is subadditive under connected sum and finite-to-one on $\\mathbb{P}^2$-irreducible and boundary-irreducible manifolds without essential annuli and M\\\"obius strips. Moreover, for these manifolds, it equals the minimal number of cubes in a cubulation of the manifold, except for the sphere, the ball, the projective space and the lens space $\\mathbb{L}_{4,1}$, which have surface-complexity zero. We will also give estimations of the surface-complexity by means of ideal triangulations and Matveev complexity.", "revisions": [ { "version": "v1", "updated": "2021-02-11T09:08:20.000Z" } ], "analyses": { "subjects": [ "57M27", "57M20" ], "keywords": [ "immersed surfaces", "matveev complexity", "lens space", "dehn surfaces", "natural number" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }