{ "id": "1209.3248", "version": "v1", "published": "2012-09-14T16:18:20.000Z", "updated": "2012-09-14T16:18:20.000Z", "title": "The Euler characteristic of a polyhedron as a valuation on its coordinate vector lattice", "authors": [ "Andrea Pedrini" ], "comment": "13 pages", "categories": [ "math.MG", "math.GT" ], "abstract": "A celebrated theorem of Hadwiger states that the Euler-Poincar\\'e characteristic is the the unique invariant and continuous valuation on the distributive lattice of compact polyhedra in R^n that assigns value one to each convex non-empty such polyhedron. This paper provides an analogue of Hadwiger's result for finitely presented unital vector lattices (i.e. real vector spaces with a compatible lattice order, also known as Riesz spaces). The vector lattice of continuous and piecewise (affine) linear real-valued functions on a compact polyhedron, with operations defined pointwise from the vector lattice R, is a finitely presented unital vector lattice; and it is a non-trivial fact that all such vector lattices arise in this manner, to within an isomorphism. Each function in such a vector lattice can be written as a linear combination of a subset of distinguished elements that we call vl-Schauder hats. We prove here that the functional that assigns to each non-negative piecewise linear function on the polyhedron the Euler-Poincar\\'e characteristic of its support is the unique vl-valuation (a special class of valuations on vector lattices) that assigns one to each vl-Schauder hat of the vector lattice.", "revisions": [ { "version": "v1", "updated": "2012-09-14T16:18:20.000Z" } ], "analyses": { "subjects": [ "06F20", "52B45", "46A40" ], "keywords": [ "coordinate vector lattice", "euler characteristic", "unital vector lattice", "vl-schauder hat", "euler-poincare characteristic" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1209.3248P" } } }