{ "id": "math/0504091", "version": "v1", "published": "2005-04-06T04:23:35.000Z", "updated": "2005-04-06T04:23:35.000Z", "title": "Navigating in the Cayley graphs of SL_N(Z) and SL_N(F_p)", "authors": [ "T. R. Riley" ], "comment": "18 pages, no figures", "journal": "Geometriae Dedicata, 113(1), pages 215-229, 2005", "categories": [ "math.GR", "math.CO" ], "abstract": "We give a non-deterministic algorithm that expresses elements of SL_N(Z), for N > 2, as words in a finite set of generators, with the length of these words at most a constant times the word metric. We show that the non-deterministic time-complexity of the subtractive version of Euclid's algorithm for finding the greatest common divisor of N > 2 integers a_1,..., a_N is at most a constant times N log n where n := max {|a_1|,..., |a_N|}. This leads to an elementary proof that for N > 2 the word metric in SL_N(Z) is biLipschitz equivalent to the logarithm of the matrix norm -- an instance of a theorem of Mozes, Lubotzky and Raghunathan. And we show constructively that there exists K>0 such that for all N > 2 and primes p, the diameter of the Cayley graph of SL_N(F_p) with respect to the generating set {e_{ij} \\mid i \\neq j} is at most K N^2 \\log p.", "revisions": [ { "version": "v1", "updated": "2005-04-06T04:23:35.000Z" } ], "analyses": { "subjects": [ "20F05" ], "keywords": [ "cayley graph", "constant times", "word metric", "greatest common divisor", "matrix norm" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......4091R" } } }