{ "id": "1408.1559", "version": "v2", "published": "2014-08-07T12:29:30.000Z", "updated": "2014-09-12T21:37:35.000Z", "title": "A Central Limit Theorem for the Length of the Longest Common Subsequence in Random Words", "authors": [ "Christian Houdré", "Ümit Işlak" ], "categories": [ "math.PR", "math.CO" ], "abstract": "Let $(X_k)_{k \\geq 1}$ and $(Y_k)_{k\\geq1}$ be two independent sequences of independent identically distributed random variables having the same law and taking their values in a finite alphabet. Let $LC_n$ be the length of longest common subsequences in the two random words $X_1\\cdots X_n$ and $Y_1\\cdots Y_n$. Under assumptions on the distribution of $X_1$, $LC_n$ is shown to satisfy a central limit theorem. This is in contrast to the limiting distribution of the length of longest common subsequences in two independent uniform random permutations of $\\{1, \\dots, n\\}$, which is shown to be the Tracy-Widom distribution.", "revisions": [ { "version": "v1", "updated": "2014-08-07T12:29:30.000Z", "abstract": "Let $(X_k)_{k \\geq 1}$ and $(Y_k)_{k\\geq1}$ be two independent sequences of independent identically distributed random variables having the same law and taking their values in a finite alphabet $\\mathcal{A}_m$. Let $LC_n$ be the length of the longest common subsequence of the random words $X_1\\cdots X_n$ and $Y_1\\cdots Y_n$. Under assumptions on the distribution of $X_1$, $LC_n$ is shown to satisfy a central limit theorem.", "comment": null, "journal": null, "doi": null }, { "version": "v2", "updated": "2014-09-12T21:37:35.000Z" } ], "analyses": { "subjects": [ "05A05", "60C05", "60F05" ], "keywords": [ "longest common subsequence", "central limit theorem", "random words", "independent identically distributed random variables", "independent sequences" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1408.1559H" } } }