{ "id": "1907.06350", "version": "v1", "published": "2019-07-15T07:10:41.000Z", "updated": "2019-07-15T07:10:41.000Z", "title": "A Constructive Proof of Jacobi's Identity for the Sum of Two Squares", "authors": [ "Mario DeFranco" ], "categories": [ "math.CO" ], "abstract": "We present a constructive proof of Jacobi's identity for the sum of two squares. We present a combinatorial proof of the Jacobi Triple Product and combine with a proof of Hirschhorn to define an algorithm. The input is a factorization $n=dN$ with $d \\equiv1\\mod 4$ plus two bits of data, and whose output is either another factorization $n=d'N'$ and $d' \\equiv3\\mod 4$ with two more bits of data, or a pair of integers whose squares sum to $n$. We phrase this algorithm in terms of integer partitions and matchings on an infinite graph.", "revisions": [ { "version": "v1", "updated": "2019-07-15T07:10:41.000Z" } ], "analyses": { "keywords": [ "jacobis identity", "constructive proof", "jacobi triple product", "infinite graph", "integer partitions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }