Abstract
Let G be a finite group. Denote by Irr(G) the set of all irreducible complex characters of G. Let \({{\rm cd}(G)=\{\chi(1)\;|\;\chi\in {\rm Irr}(G)\}}\) be the set of all irreducible complex character degrees of G forgetting multiplicities, and let X1(G) be the set of all irreducible complex character degrees of G counting multiplicities. Let H be any non-abelian simple exceptional group of Lie type. In this paper, we will show that if S is a non-abelian simple group and \({{\rm cd}(S)\subseteq {\rm cd}(H)}\) then S must be isomorphic to H. As a consequence, we show that if G is a finite group with \({{\rm X}_1(G)\subseteq {\rm X}_1(H)}\) then G is isomorphic to H. In particular, this implies that the simple exceptional groups of Lie type are uniquely determined by the structure of their complex group algebras.
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References
Berkovich, Y., Zhmud́, E.: Characters of finite groups. Part 1. In: Translations of Mathematical Monographs, vols. 172, 181. AMS, Providence (1997)
Carter R.: Finite Groups of Lie Type. Conjugacy Classes and Complex Characters. Wiley, New York (1985)
Chang, B., Ree, R.: The characters of G 2(q). In: Symposia Mathematica, vol. XIII (Convegno di Gruppi e loro Rappresentazioni, INDAM, Rome), pp. 395–413 (1972)
Conway J.H., Curtis R.T., Norton S.P., Parker R.A., Wilson R.A.: Atlas of Finite Groups. Oxford University Press, Eynsham (1985)
Deriziotis D.I., Michler G.O.: Character table and blocks of finite simple triality groups 3 D 4(q). Trans. Am. Math. Soc. 303(1), 39–70 (1987)
Enomoto H.: The characters of the finite symplectic group Sp(4, q), q = 2f. Osaka J. Math. 9, 75–94 (1972)
Enomoto H.: The characters of the finite Chevalley group G 2(q), q = 3f. Jpn. J. Math. (N.S.) 2(2), 191–248 (1976)
Enomoto H., Yamada H.: The characters of G 2(2n). Jpn. J. Math. (N.S.) 12(2), 325–377 (1986)
The GAP Group, GAP-Groups: Algorithms, and Programming, Version 4.4.10. http://www.gap-system.org (2007)
Hagie M.: The prime graph of a sporadic simple group. Commun. Algebra 31(9), 4405–4424 (2003)
Huppert B.: Some simple groups which are determined by the set of their character degrees. I. Illinois J. Math. 44(4), 828–842 (2000)
Isaacs, M.: Character Theory of Finite Groups. Corrected reprint of the 1976 original [Academic Press, New York]. AMS Chelsea Publishing, Providence (2006)
Kleidman, P., Liebeck, M.W.: The subgroup structure of the finite classical groups. In: LMS Lecture Note Series, vol. 129. Cambridge University Press (1990)
Lübeck F.: Smallest degrees of representations of exceptional groups of Lie type. Commun. Algebra 29(5), 2147–2169 (2001)
Lübeck, R.: http://www.math.rwth-aachen.de/~Frank.Luebeck/chev/DegMult/index.html
Malle G., Moretó A.: Nonsolvable groups with few character degrees. J. Algebra 294(1), 117–126 (2005)
Malle G., Zalesskii A.: Prime power degree representations of quasi-simple groups. Arch. Math. (Basel) 77(6), 461–468 (2001)
Maróti A.: Bounding the number of conjugacy classes of a permutation group. J. Group Theory 8(3), 273–289 (2005)
Mazurov, V.D., Khukhro, E.I. (eds.): Unsolved Problems in Group Theory. The Kourovka Notebook, No. 16. Inst. Mat. Sibirsk. Otdel. Akad. Novosibirsk (2006)
Seitz G.: Cross-characteristic embeddings of finite groups of Lie type, finite and algebraic. Proc. LMS 60, 166–200 (1990)
Shahabi, M.A., Mohtadifar, H.: The characters of finite projective symplectic group PSp(4, q). In: Groups St. Andrews 2001 in Oxford, vol. II, pp. 496–527. London Math. Soc. Lecture Note Ser., vol. 305. Cambridge University Press, Cambridge (2003)
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)
Suzuki M.: On a class of doubly transitive groups. Ann. Math. (2) 75, 105–145 (1962)
Tong-Viet, H.P.: Alternating and sporadic simple groups are determined by their character degrees. Algebr. Represent. Theory. doi:10.1007/s10468-010-9247-1 (2010)
Tong-Viet, H.P.: Simple classical groups of Lie type are determined by their character degrees. Preprint
Tong-Viet, H.P.: Symmetric groups are determined by their character degrees. J. Algebra. doi:10.1016/j.jalgebra.2010.11.018 (2011)
Ward H.N.: On Ree’s series of simple groups. Trans. Am. Math. Soc. 121, 62–89 (1966)
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Communicated by John S. Wilson.
The author is supported by a post-doctoral fellowship from the University of KwaZulu-Natal.
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Tong-Viet, H.P. Simple exceptional groups of Lie type are determined by their character degrees. Monatsh Math 166, 559–577 (2012). https://doi.org/10.1007/s00605-011-0301-9
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DOI: https://doi.org/10.1007/s00605-011-0301-9