{ "id": "1912.00577", "version": "v1", "published": "2019-12-02T04:10:08.000Z", "updated": "2019-12-02T04:10:08.000Z", "title": "More on Poincare-Hopf and Gauss-Bonnet", "authors": [ "Oliver Knill" ], "comment": "12 pages, 11 figures", "categories": [ "math.CO", "cs.DM" ], "abstract": "We illustrate connections between differential geometry on finite simple graphs G=(V,E) and Riemannian manifolds (M,g). The link is that curvature can be defined integral geometrically as an expectation in a probability space of Poincare-Hopf indices of coloring or Morse functions. Regge calculus with an isometric Nash embedding links then the Gauss-Bonnet-Chern integrand of a Riemannian manifold with the graph curvature. There is also a direct nonstandard approach: if V is a finite set containing all standard points of M and E contains pairs which are infinitesimally close in the sense of internal set theory, one gets a finite simple graph (V,E) which gets a curvature which as a measure corresponds to the standard curvature. The probabilistic approach is an umbrella framework which covers discrete spaces, piecewise linear spaces, manifolds or varieties.", "revisions": [ { "version": "v1", "updated": "2019-12-02T04:10:08.000Z" } ], "analyses": { "subjects": [ "05C10", "57M15", "03H05", "62-07", "62-04" ], "keywords": [ "finite simple graph", "riemannian manifold", "gauss-bonnet", "internal set theory", "isometric nash embedding links" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }