{ "id": "math/0609723", "version": "v5", "published": "2006-09-26T10:01:01.000Z", "updated": "2007-01-10T09:30:03.000Z", "title": "On prime factors of class number of cyclotomic fields", "authors": [ "Roland Queme" ], "comment": "The numerical MAPLE algorithm of the section 5 p. 18 is added", "categories": [ "math.NT" ], "abstract": "Let p be an odd prime. Let K = \\Q(zeta) be the p-cyclotomic number field. Let v be a primitive root mod p and sigma : zeta --> zeta^v be a \\Q-isomorphism of the extension K/\\Q generating the Galois group G of K/\\Q. For n in Z, the notation v^n is understood by v^n mod p with 1 \\leq v^n \\leq p-1. Let P(X) = \\sum_{i=0}^{p-2} v^{-i}X^i \\in \\Z[X] be the Stickelberger polynomial. P(sigma) annihilates the class group C of K. There exists a polynomial Q(X) \\in \\Z[X] such that P(sigma)(sigma-v) = p\\times Q(sigma) and such that Q(sigma) annihilates the p-class group C_p of K (the subgroup of exponent p of C). In the other hand sigma^{(p-1)/2}+1 annihilates the relative class group of K. The simultaneous application of these results brings some informations on the structure of the class group C, give some explicit congruences in \\Z[v] mod p for the p-class group C_p of K and some explicit congruences in \\Z[v] mod h for the h-class group of K for all the prime divisors h \\not = p of the class number h(K). We detail at the end the case of class number of quadratic and biquadratic fields contained in the cyclotomic field K and give a general MAPLE algorithm.", "revisions": [ { "version": "v5", "updated": "2007-01-10T09:30:03.000Z" } ], "analyses": { "subjects": [ "11R18", "11R29" ], "keywords": [ "class number", "cyclotomic field", "prime factors", "explicit congruences", "p-class group" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......9723Q" } } }