Skip to main content
Log in

Variations of Landau’s theorem for p-regular and p-singular conjugacy classes

  • Published:
Israel Journal of Mathematics Aims and scope Submit manuscript

Abstract

The well-known Landau’s theorem states that, for any positive integer k, there are finitely many isomorphism classes of finite groups with exactly k (conjugacy) classes. We study variations of this theorem for p-regular classes as well as p-singular classes. We prove several results showing that the structure of a finite group is strongly restricted by the number of p-regular classes or the number of p-singular classes of the group. In particular, if G is a finite group with O p (G) = 1 then |G/F(G)| p' is bounded in terms of the number of p-regular classes of G. However, it is not possible to prove that there are finitely many groups with no nontrivial normal p-subgroup and k p-regular classes without solving some extremely difficult number-theoretic problems (for instance, we would need to show that the number of Fermat primes is finite).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. L. Babai, S. Guest, C. E. Praeger and R. A. Wilson, Proportions of r-regular elements in finite classical groups, Journal of the London Mathematical Society 88 (2013), 202–226.

    Article  MathSciNet  MATH  Google Scholar 

  2. L. Babai, P. P. Pálfy and J. Saxl, On the number of p-regular elements in finite simple groups, LMS Journal of Computation and Mathematics 12 (2009), 82–119.

    Article  MathSciNet  MATH  Google Scholar 

  3. R. Brauer, Representations of finite groups, in Lectures on Modern Mathematics, Vol. I, Wiley, New York, 1963, pp. 133–175.

    MATH  Google Scholar 

  4. Y. Bugeaud, Z. Cao and M. Mignotte, On simple K4-groups, Journal of Algebra 241 (2001), 658–668.

    Article  MathSciNet  MATH  Google Scholar 

  5. S. T. Burkett and H. N. Nguyen, Conjugacy classes of small sizes in the linear and unitary groups, Journal of Group Theory 16 (2013), 851–874.

    Article  MathSciNet  MATH  Google Scholar 

  6. J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, Atlas of Finite Groups, Oxford University Press, Eynsham, 1985.

    MATH  Google Scholar 

  7. D. A. Craven, Symmetric group character degrees and hook numbers, Proceedings of the London Mathematical Society 96 (2008), 26–50.

    Article  MathSciNet  MATH  Google Scholar 

  8. W. Feit, On large Zsigmondy primes, Proceedings of the American Mathematical Society 102 (1988), 29–36.

    Article  MathSciNet  MATH  Google Scholar 

  9. J. Fulman and R. Guralnick, Bounds on the number and sizes of conjugacy classes in finite Chevalley groups with applications to derangements, Transactions of the American Mathematical Society 364 (2012), 3023–3070.

    Article  MathSciNet  MATH  Google Scholar 

  10. The GAP Group, GAP—Groups, Algorithms, and Programming, Version 4.6.2, 2013, http://www.gap-system.org.

  11. D. Gorenstein, Finite Simple Groups. An Introduction to their Classification, University Series in Mathematics, Plenum Publishing Corp., New York, 1982.

    MATH  Google Scholar 

  12. D. Gorenstein, R. Lyons and R. Solomon, The Classification of the Finite Simple Groups. Number 3. Part I. Chapter A, Mathematical Surveys and Monographs, Vol. 40, American Mathematical Society, Providence, RI, 1998.

    MATH  Google Scholar 

  13. M. Herzog, On finite simple groups of order divisible by three primes only, Journal of Algebra 10 (1968), 383–388.

    Article  MathSciNet  MATH  Google Scholar 

  14. L. Héthelyi and B. Külshammer, Elements of prime power order and their conjugacy classes in finite groups, Journal of the Australian Mathematical Society 78 (2005), 291–295.

    Article  MathSciNet  MATH  Google Scholar 

  15. I. M. Isaacs, W. M. Kantor and N. Spaltenstein, On the probability that a group element is p-singular, Journal of Algebra 176 (1995), 139–181.

    Article  MathSciNet  MATH  Google Scholar 

  16. A. Jaikin-Zapirain, On two conditions on characters and conjugacy classes in finite soluble groups, Journal of Group Theory 8 (2005), 267–272.

    Article  MathSciNet  MATH  Google Scholar 

  17. C. Jansen, K. Lux, R. Parker and R. Wilson, An Atlas of Brauer Characters, London Mathematical Society Monographs, Vol. 11, The Clarendon Press, Oxford University Press, New York, 1995.

    MATH  Google Scholar 

  18. T. M. Keller, Finite groups have even more conjugacy classes, Israel Journal of Mathematics 181 (2011), 433–444.

    Article  MathSciNet  MATH  Google Scholar 

  19. B. Külshammer, Blocks, solvable groups, and Landau’s theorem, Journal für die Reine und Angewandte Mathematik 398 (1989), 180–186.

    MATH  Google Scholar 

  20. B. Külshammer, Landau’s theorem for p-blocks of p-solvable groups, Journal für die Reine und Angewandte Mathematik 404 (1990), 189–191.

    MATH  Google Scholar 

  21. B. Külshammer and G. R. Robinson, Alperin–McKay implies Brauer’s problem 21, Journal of Algebra 180 (1996), 208–210.

    Article  MathSciNet  MATH  Google Scholar 

  22. E. Landau, Über die Klassenzahl der binären quadratischen Formen von negativer Discriminante, Mathematische Annalen 56 (1903), 671–676.

    Article  MathSciNet  Google Scholar 

  23. M. L. Lewis and J. M. Riedl, Affine semi-linear groups with three irreducible character degrees, Journal of Algebra 246 (2001), 708–720.

    Article  MathSciNet  MATH  Google Scholar 

  24. O. Manz and T. R. Wolf, Representations of Solvable Groups, London Mathematical Society Lecture Notes Series, Vol. 185, Cambridge University Press, Cambridge, 1993.

    Book  MATH  Google Scholar 

  25. A. Maróti and H. N. Nguyen, On the number of conjugacy classes of π-elements in finite groups, Archiv der Mathematik 102 (2014), 101–108.

    Article  MathSciNet  MATH  Google Scholar 

  26. A. Moretó, Complex group algebras of finite groups: Brauer’s problem 1, Advances in Mathematics 208 (2007), 236–248.

    Article  MathSciNet  MATH  Google Scholar 

  27. A. Moretó, J. Sangroniz and A. Turull, Sylow subgroups and the number of conjugacy classes of p-elements, Journal of Algebra 275 (2004), 668–674.

    Article  MathSciNet  MATH  Google Scholar 

  28. H. N. Nguyen, Low-dimensional complex characters of the symplectic and orthogonal groups, Communications in Algebra 38 (2010), 1157–1197.

    Article  MathSciNet  MATH  Google Scholar 

  29. H. N. Nguyen, Multiplicities of conjugacy class sizes of finite groups, Journal of Algebra 341 (2011), 250–255.

    Article  MathSciNet  MATH  Google Scholar 

  30. Y. Ninomiya, Finite groups with exactly three p-regular classes, Archiv der Mathematik 57 (1991), 105–108.

    Article  MathSciNet  MATH  Google Scholar 

  31. Y. Ninomiya, Structure of p-solvable groups with three p-regular classes, Canadian Journal of Mathematics 43 (1991), 559–579.

    Article  MathSciNet  MATH  Google Scholar 

  32. Y. Ninomiya, Structure of p-solvable groups with three p-regular classes II, Mathematical Journal of Okayama University 35 (1993), 29–34.

    MathSciNet  MATH  Google Scholar 

  33. Y. Ninomiya and T. Wada, Cartan matrices for blocks of finite p-solvable groups with two simple modules, Journal of Algebra 143 (1991), 315–333.

    Article  MathSciNet  MATH  Google Scholar 

  34. D. S. Passman, Character theory and group rings, in Character Theory of Finite Groups, Contemporary Mathematics, Vol. 524, American Mathematical Society, Providence, RI, 2010, pp. 139–148.

    Book  MATH  Google Scholar 

  35. M. Roitman, On Zsigmondy primes, Proceedings of the American Mathematical Society 125 (1997), 1913–1919.

    Article  MathSciNet  MATH  Google Scholar 

  36. S. M. Seager, A bound on the rank of primitive solvable permutation groups, Journal of Algebra 116 (1988), 342–352.

    Article  MathSciNet  MATH  Google Scholar 

  37. W. A. Simpson and J. S. Frame, The character tables for SL(3, q), SU(3, q 2), PSL(3, q), PSU(3, q 2), Canadian Journal of Mathematics 25 (1973), 486–494.

    Article  MathSciNet  MATH  Google Scholar 

  38. M. Suzuki, On a class of doubly transitive groups, Annals of Mathematics 75 (1962), 105–145.

    Article  MathSciNet  MATH  Google Scholar 

  39. G. Tiedt, About finite solvable groups with exactly four p-regular conjugacy classes, Hokkaido Mathematical Journal 25 (1996), 249–258.

    Article  MathSciNet  MATH  Google Scholar 

  40. H. N. Ward, On Ree’s series of simple groups, Transactions of the AmericanMathematical Society 121 (1966), 62–89.

    MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Alexander Moretó or Hung Ngoc Nguyen.

Additional information

The research of the first author was supported by the Spanish Ministerio de Ciencia y Tecnología, grant MTM2010-15296 and PROMETEO/Generalitat Valenciana.

The second author is partially supported by the NSA Young Investigator Grant #H98230-14-1-0293 and a BCAS Faculty Scholarship Award from the Buchtel College of Arts and Sciences, The University of Akron.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Moretó, A., Nguyen, H.N. Variations of Landau’s theorem for p-regular and p-singular conjugacy classes. Isr. J. Math. 212, 961–987 (2016). https://doi.org/10.1007/s11856-016-1316-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11856-016-1316-7

Navigation