Abstract
Let G be a finite group, and write \(\mathrm{cd}(G)\) for the degree set of the complex irreducible characters of G. The group G is said to satisfy the two-prime hypothesis if, for any distinct degrees \(a, b \in \mathrm{cd}(G)\), the total number of (not necessarily different) primes of the greatest common divisor \(\gcd (a, b)\) is at most 2. In this paper, we determine the nonabelian chief factors that can occur for groups satisfying the two-prime hypothesis.
Similar content being viewed by others
References
Bianchi, M., Chillag, D., Lewis, M.L., Pacifici, E.: Character degree graphs that are complete graphs. Proc. Am. Math. Soc. 135, 671-676 (2007)
Bosma, W., Cannon, J., Playoust, C.: The Magma algebra system I: the user language. J. Symb. Comput. 24, 235-265 (1997)
Carter, R.W.: Finite Groups of Lie Type: Conjugacy Classes and Complex Characters. Wiley, Chichester (1985)
Conway, J.H., Curtis, R.T., Norton, S.P., Parker, R.A., Wilson, R.A.: Atlas of Finite Groups. Oxford University Press, London (1984)
Hamblin, J.: Solvable groups satisfying the two-prime hypothesis I. Algebras Represent. Theory 10, 1-24 (2007)
Hamblin, J., Lewis, M.L.: Solvable groups satisfying the two-prime hypothesis II. Algebras Represent. Theory 15, 1099-1130 (2012)
Isaacs, I.M.: Character Theory of Finite Groups. Academic Press, San Diego (1976)
James, G.: The Representation Theory of the Symmetric Groups. Lecture Notes in Math, vol. 682. Springer, New York (1978)
Karpilovsky, G.: Group Representations, vol. 3, North-Holland Mathematics Studies, 180. North-Holland Publishing Co., Amsterdam (1994)
Lewis, M.L.: The number of irreducible character degrees of solvable groups satisfying the one-prime hypothesis. Algebras Represent. Theory 8, 479-497 (2005)
Lewis, M.L., White, D.L.: Connectedness of degree graphs of nonsolvable groups. J. Algebra 266, 51-76 (2003)
Lewis, M.L., White, D.L.: Nonsolvable groups satisfying the one-prime hypothesis. Algebras Represent. Theory 10, 379-412 (2007)
Lewis, M.L., White, D.L.: Nonsolvable groups with no prime dividing three character degrees. J. Algebra 336, 158-183 (2011)
Malle, G.: Extensions of unipotent characters and the inductive McKay condition. J. Algebra 320, 2963-2980 (2008)
Manz, O., Staszewski, R., Willems, W.: On the number of components of a graph related to character degrees. Proc. Am. Math. Soc. 103, 31-37 (1988)
Schmid, P.: Rational matrix groups of a special type. Linear Algebra Appl. 71, 289-293 (1985)
Schmid, P.: Extending the Steinberg representation. J. Algebra 150, 254-256 (1992)
Simpson, W.A., Frame, J.S.: The character tables for SL(3, $q$), SU(3, $q^{2}$), PSL(3, $q$), PSU(3, $q^{2}$). Can. J. Math. 25, 486-494 (1973)
Srinivasan, B.: The characters of the finite symplectic group Sp(4, $q$). Trans. Am. Math. Soc. 131, 488-525 (1968)
The GAP Group, GAP–groups, algorithms, and programming, version 4.5. http://www.gap-system.org (2012)
Ward, H.: On Ree’s series of simple groups. Trans. Am. Math. Soc. 121, 62-89 (1966)
Acknowledgments
This project was started while both authors took part in the “Third International Symposium on Groups, Algebras and Related topics in Beijing, celebrating the 50th Anniversary of the Journal of Algebra”. The authors would like to express their deep thanks to the Beijing International Center for Mathematical Research, and particularly Professor Jiping Zhang, for encouraging them to get together to focus on the topic of this paper. The second author was partially supported by the National Natural Science Foundation of China (11201194) and (11471054) and the Science Foundation of Jiangxi Province for Youths (20142BAB211011). Finally, the authors are deeply indebted to the anonymous referee from Algebra and Representation Theory who carefully read our previous long manuscript and made many corrections and suggestions. This leads to the present four-part division of the whole work.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by J. S. Wilson.
Rights and permissions
About this article
Cite this article
Lewis, M.L., Liu, Y. Simple groups and the two-prime hypothesis. Monatsh Math 181, 855–867 (2016). https://doi.org/10.1007/s00605-015-0839-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00605-015-0839-z