{ "id": "math/0603415", "version": "v1", "published": "2006-03-16T23:18:14.000Z", "updated": "2006-03-16T23:18:14.000Z", "title": "On the determination of sets by their triple correlation in finite cyclic groups", "authors": [ "Tamas Keleti", "Mihail N. Kolountzakis" ], "comment": "17 pages", "categories": [ "math.CO", "math.NT" ], "abstract": "Let $G$ be a finite abelian group and $E$ a subset of it. Suppose that we know for all subsets $T$ of $G$ of size up to $k$ for how many $x \\in G$ the translate $x+T$ is contained in $E$. This information is collectively called the $k$-deck of $E$. One can naturally extend the domain of definition of the $k$-deck to include functions on $G$. Given the group $G$ when is the $k$-deck of a set in $G$ sufficient to determine the set up to translation? The 2-deck is not sufficient (even when we allow for reflection of the set, which does not change the 2-deck) and the first interesting case is $k=3$. We further restrict $G$ to be cyclic and determine the values of $n$ for which the 3-deck of a subset of $\\ZZ_n$ is sufficient to determine the set up to translation. This completes the work begun by Gr\\\"unbaum and Moore as far as the 3-deck is concerned. We additionally estimate from above the probability that for a random subset of $\\ZZ_n$ there exists another subset, not a translate of the first, with the same 3-deck. We give an exponentially small upper bound when the previously known one was $O(1\\bigl / \\sqrt{n})$.", "revisions": [ { "version": "v1", "updated": "2006-03-16T23:18:14.000Z" } ], "analyses": { "subjects": [ "43A25" ], "keywords": [ "finite cyclic groups", "triple correlation", "determination", "finite abelian group", "exponentially small upper bound" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......3415K" } } }