{ "id": "1212.3822", "version": "v2", "published": "2012-12-16T19:37:15.000Z", "updated": "2013-09-30T02:02:42.000Z", "title": "The Satisfiability Threshold for $k$-XORSAT, using an alternative proof", "authors": [ "Boris Pittel", "Gregory B. Sorkin" ], "comment": "This version integrates the previous version's alternative proof into the paper (see arXiv:1212.1905). Other proofs are amended, and the paper's structure is clarified. The main result is improved: the phase transition occurs for an arbitrarily slowly growing gap between m and n", "categories": [ "math.CO" ], "abstract": "We consider \"unconstrained\" random $k$-XORSAT, which is a uniformly random system of $m$ linear non-homogeneous equations in $\\mathbb{F}_2$ over $n$ variables, each equation containing $k \\ge 3$ variables, and also consider a \"constrained\" model where every variable appears in at least two equations. Dubois and Mandler proved that $m/n=1$ is a sharp threshold for satisfiability of constrained 3-XORSAT, and analyzed the 2-core of a random 3-uniform hypergraph to extend this result to find the threshold for unconstrained 3-XORSAT. We show that $m/n=1$ remains a sharp threshold for satisfiability of constrained $k$-XORSAT for every $k \\ge 3$, and we use standard results on the 2-core of a random $k$-uniform hypergraph to extend this result to find the threshold for unconstrained $k$-XORSAT. For constrained $k$-XORSAT we narrow the phase transition window, showing that $n-m \\to \\infty$ implies almost-sure satisfiability, while $m-n \\to \\infty$ implies almost-sure unsatisfiability.", "revisions": [ { "version": "v2", "updated": "2013-09-30T02:02:42.000Z" } ], "analyses": { "keywords": [ "satisfiability threshold", "alternative proof", "sharp threshold", "implies almost-sure unsatisfiability", "phase transition window" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1212.3822P" } } }