Available in electronic format
Available in print format
Mathematics of Computation
Journal of the American Mathematical Society
ISSN 1088-6842(e) ISSN 0025-5718(p)
     

On the computation of class numbers of real abelian fields

Author(s): Tuomas Hakkarainen.
Journal: Math. Comp. 78 (2009), 555-573.
MSC (2000): Primary 11R29, 11Y40; Secondary 11R20, 11R27
Posted: September 4, 2008
Retrieve article in: PDF

Abstract | References | Similar articles | Additional information

Abstract: In this paper we give a procedure to search for prime divisors of class numbers of real abelian fields and present a table of odd primes $ <10000$ not dividing the degree that divide the class numbers of fields of conductor $ \leq 2000$. Cohen-Lenstra heuristics allow us to conjecture that no larger prime divisors should exist. Previous computations have been largely limited to prime power conductors.


References:

1.
M. Aoki, Notes on the structure of the ideal class groups of abelian number fields, Proc. Japan Acad. Ser. A Math. Sci. 81 (2005), no. 5, pp. 69-74. MR 2143545 (2006a:11142)

2.
J. Buhler, C. Pomerance, L. Robertson, Heuristics for class numbers of prime-power real cyclotomic fields, High primes and misdemeanours: lectures in honour of the 60th birthday of Hugh Cowie Williams, Fields Inst. Commun. 41, Amer. Math. Soc., Providence, RI (2004), pp. 149-157. MR 2073643 (2005e:11143)

3.
H. Cohen, H. W. Lenstra, Heuristics on class groups of number fields, Number theory, Noordwijkerhout 1983 (Noordwijkerhout, 1983), Lecture Notes in Math. 1068, Springer, Berlin (1984), pp. 33-62. MR 756082 (85j:11144)

4.
C.-E. Fröberg, On the prime zeta function, BIT 8 (1968), pp. 187-202. MR 0236123 (38:4421)

5.
G. Gras and M.-N. Gras, Calcul du nombre de classes et des unités des extensions abéliennes réelles de $ \mathbf{Q}$, Bull. Sci. Math. (2) 101 (1977), no. 2, pp. 97-129. MR 0480423 (58:586)

6.
M.-N. Gras, Méthodes et algorithmes pour le calcul numérique du nombre de classes et des unités des extensions cubiques cycliques de $ \mathbf{Q}$, J. Reine Angew. Math. 277 (1975), pp. 89-116. MR 0389845 (52:10675)

7.
M.-N. Gras, Table numérique du nombre de classes et des unités dans les extensions cycliques réelles de degre $ 4$ de $ \mathbf{Q}$, Publ. Math. Fac. Sci. Besançon 1977/78, Fasc. 2 (1978), 52 pp.

8.
T. Hakkarainen, On the computation of the class numbers of real abelian fields, TUCS Dissertations no. 87, Turku Centre for Computer Science (2007), 81 pp. Available at http://www.tucs.fi/

9.
S. Jeannin, Tables des nombres de classes et unités des corps quintiques cycliques de conducteur $ f\leq 10000$, Publ. Math. Fac. Sci. Besançon 1994/95-1995/96 (1997), 40 pp. MR 1449427 (98b:11129)

10.
S. Kobayashi, Divisibilité du nombre de classes des corps abéliens réels, J. Reine Angew. Math. 320 (1980), pp. 142-149. MR 592150 (82f:12009)

11.
Y. Koyama and K. Yoshino, Prime divisors of real class number of $ p^r$th cyclotomic field and characteristic polynomials attached to them, Preprint (2003), 23 pp.

12.
H. W. Leopoldt, Über Einheitengruppe und Klassenzahl reeller abelscher Zahlkörper, Abh. Deutsch. Akad. Wiss. Berlin. Kl. Math. Nat. 1953, no. 2 (1954), 48 pp. MR 0067927 (16:799d)

13.
H. W. Leopoldt, Über Klassenzahlprimteiler reeller abelscher Zahlkörper als Primteiler verallgemeinerter Bernoullischer Zahlen, Abh. Math. Sem. Univ. Hamburg 23 (1959), pp. 36-47. MR 0103184 (21:1967)

14.
F. van der Linden, Class number computations of real abelian number fields, Math. Comp. 39 (1982), pp. 693-707. MR 669662 (84e:12005)

15.
S. Mäki, The determination of units in real cyclic sextic fields, Lecture Notes in Math. 797, Springer, Berlin (1980), 198 pp. MR 584794 (82a:12004)

16.
T. Metsänkylä, An application of the $ p$-adic class number formula, Manuscripta Math. 93 (1997), pp. 481-498. MR 1465893 (98m:11118)

17.
B. Oriat, Groupes des classes d'idéaux des corps quadratiques réels $ \mathbf{Q}(d^{1/2}),\, 1<d<24572$, Publ. Math. Fac. Sci. Besançon 1986/87-1987/88, Fasc. 2 (1988), 65 pp. MR 983124 (90e:11167a)

18.
PARI/GP, version 2.2.8, Bordeaux, 2005, http://pari.math.u-bordeaux.fr/

19.
S. Perlis and G. Walker, Abelian group algebras of finite order, Trans. Amer. Math. Soc. 68 (1950), pp. 420-426. MR 0034758 (11:638k)

20.
R. Schoof, Class numbers of real cyclotomic fields of prime conductor, Math. Comp. 72 (2003), pp. 913-937. MR 1954975 (2004f:11116)

21.
W. Schwarz, Über die Klassenzahl abelscher Zahlkörper, Ph.D. Thesis, University of Saarbrücken (1995), 125 pp.

22.
L. Washington, Introduction to Cyclotomic Fields, 2nd ed., Springer, New York, 1997. MR 1421575 (97h:11130)

23.
C. Wittmann, $ p$-class groups of certain extensions of degree $ p$, Math. Comp. 74 (2005), pp. 937-947. MR 2114656 (2005h:11256)

24.
Wolfram Research, Inc., Mathematica, Version 4.1, Champaign, IL (2001).


Similar Articles:

Retrieve articles in Mathematics of Computation with MSC (2000): 11R29, 11Y40, 11R20, 11R27

Retrieve articles in all Journals with MSC (2000): 11R29, 11Y40, 11R20, 11R27


Additional Information:

Tuomas Hakkarainen
Affiliation: Department of Mathematics & TUCS, Turku Centre for Computer Science, University of Turku, FI-20014 Turku, Finland

DOI: 10.1090/S0025-5718-08-02169-8
PII: S 0025-5718(08)02169-8
Keywords: Class numbers, computation, abelian fields, units
Received by editor(s): April 28, 2006
Posted: September 4, 2008
Additional Notes: This work was financially supported by the Turku Centre for Computer Science, TUCS
Copyright of article: Copyright 2008, American Mathematical Society
The copyright for this article reverts to public domain after 28 years from publication.


  AMS Website Logo Small Comments: webmaster@ams.org
© Copyright 2009, American Mathematical Society
Privacy Statement
Search the AMSPowered by Google