{ "id": "1907.03369", "version": "v1", "published": "2019-07-07T23:47:46.000Z", "updated": "2019-07-07T23:47:46.000Z", "title": "The energy of a simplicial complex", "authors": [ "Oliver Knill" ], "comment": "34 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "A finite abstract simplicial complex G defines a matrix L, where L(x,y)=1 if two simplicies x,y in G intersect and where L(x,y)=0 if they don't. This matrix is always unimodular so that the inverse g of L has integer entries g(x,y). In analogy to Laplacians on Euclidean spaces, these Green function entries define a potential energy between two simplices x,y. We prove that the total energy summing all matrix elements g(x,y) is equal to the Euler characteristic X(G) of G and that the number of positive minus the number of negative eigenvalues of L is equal to X(G).", "revisions": [ { "version": "v1", "updated": "2019-07-07T23:47:46.000Z" } ], "analyses": { "subjects": [ "05C10", "57M15", "68R10" ], "keywords": [ "finite abstract simplicial complex", "green function entries define", "euclidean spaces", "integer entries", "potential energy" ], "note": { "typesetting": "TeX", "pages": 34, "language": "en", "license": "arXiv", "status": "editable" } } }