{ "id": "1411.3527", "version": "v1", "published": "2014-11-13T12:49:48.000Z", "updated": "2014-11-13T12:49:48.000Z", "title": "Finite-dimensional representations of difference operators, and the identification of remarkable matrices", "authors": [ "Francesco Calogero" ], "comment": "29 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "Two square matrices of (arbitrary) order N are introduced. They are defined in terms of N arbitrary numbers z_{n}, and of an arbitrary additional parameter (a respectively q), and provide finite-dimensional representations of the two operators acting on a function f(z) as follows: [f(z+a)-f(z)]/a respectively [f(qz)-f(z)]/[(q-1)z]. These representations are exact---in a sense explained in the paper---when the function f(z) is a polynomial in z of degree less than N. This formalism allows to transform difference equations valid in the space of polynomials of degree less than N into corresponding matrix-vector equations. As an application of this technique several remarkable square matrices of order N are identified, which feature explicitly N arbitrary numbers z_{n}, or the N zeros of polynomials belonging to the Askey and q-Askey schemes. Several of these findings have a Diophantine character.", "revisions": [ { "version": "v1", "updated": "2014-11-13T12:49:48.000Z" } ], "analyses": { "keywords": [ "finite-dimensional representations", "difference operators", "identification", "transform difference equations valid", "arbitrary numbers" ], "tags": [ "journal article" ], "publication": { "doi": "10.1063/1.4915291", "journal": "Journal of Mathematical Physics", "year": 2015, "month": "Mar", "volume": 56, "number": 3, "pages": "033506" }, "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015JMP....56c3506C" } } }