Non-solvable Groups whose Character Degree Graph has a Cut-Vertex. I

Vietnam Journal of Mathematics - Tập 51 - Trang 731-753 - 2023
Silvio Dolfi1, Emanuele Pacifici1, Lucia Sanus2, Victor Sotomayor3
1Dipartimento di Matematica e Informatica U. Dini, Universitá degli Studi di Firenze, Firenze, Italy
2Departament de Matemàtiques, Facultat de Matemàtiques, Universitat de Valencia, Valencia, Spain
3Instituto Universitario de Matemática Pura y Aplicada (IUMPA-UPV), Universitat Politécnica de València, Valencia, Spain

Tóm tắt

Let G be a finite group. Denoting by $$\textrm{cd}(G)$$ the set of degrees of the irreducible complex characters of G, we consider the character degree graph of G: this is the (simple undirected) graph whose vertices are the prime divisors of the numbers in $$\textrm{cd}(G)$$ , and two distinct vertices p, q are adjacent if and only if pq divides some number in $$\textrm{cd}(G)$$ . In the series of three papers starting with the present one, we analyze the structure of the finite non-solvable groups whose character degree graph possesses a cut-vertex, i.e. a vertex whose removal increases the number of connected components of the graph.

Tài liệu tham khảo

Akhlaghi, Z., Casolo, C., Dolfi, S., Pacifici, E., Sanus, L.: On the character degree graph of finite groups. Ann. Mat. Pura Appl. 198, 1595–1614 (2019) Alperin, J.L., Gorenstein, D.: The multiplicators of certain simple groups. Proc. Amer. Math. Soc. 17, 515–519 (1966) Aschbacher, M.: Finite Group Theory. Cambridge University Press (1986) Casolo, C.: Some linear actions of finite groups with \(q^{\prime }\)-orbits. J. Group Theory 13, 503–534 (2010) Conway, J.H., Curtis, R.T., Norton, S.P., Parker, R.A., Wilson, R.A.: Atlas of Finite Groups. Oxford University Press, London (1984) Diestel, R.: Graph Theory. Graduate Texts in Mathematics, vol. 173. Springer, Berlin, Heidelberg (2010) Dolfi, S., Khedri, K., Pacifici, E.: Groups whose degree graph has three independent vertices. J. Algebra 512, 66–80 (2018) Dolfi, S., Pacifici, E., Sanus, L.: Non-solvable groups whose character degree graph has a cut-vertex. II. Ann. Mat. Pura Appl. 202, 1753–1780 (2023) Dolfi, S., Pacifici, E., Sanus, L.: Non-solvable groups whose character degree graph has a cut-vertex. III. Ann. Mat. Pura Appl. (2023). https://doi.org/10.1007/s10231-023-01328-9 Dolfi, S., Pacifici, E., Sanus, L., Sotomayor, V.: Groups whose prime graph on class sizes has a cut vertex. Isr. J. Math. 244, 775–805 (2021) Ebrahimi, M., Khatami, M., Mirzaei, Z.: 1-connected character-graphs of finite groups with non-bipartite complement. J. Algebra Appl. 20, 2150058 (2021) Fawcett, J.B., Müller, J., O’Brien, E.A., Wilson, R.A.: Regular orbits of sporadic simple groups. J. Algebra 522, 61–79 (2019) The GAP Group, GAP – Groups, Algorithms, and Programming, Version 4.11.1 (2021).https://www.gap-system.org Ghaffarzadeh, M.: Character degrees of extensions of the Suzuki groups \(^2B_2(q^2)\). J. Algebra Appl. 17, 1850006 (2018) Giudici, M., Liebeck, M., Praeger, C., Saxl, J., Tiep, P.H.: Arithmetic results on orbits of linear groups. Trans. Amer. Math. Soc. 368, 2415–2467 (2016) Huppert, B.: Endliche Gruppen I. Springer, Berlin (1967) Isaacs, I.M.: Character Theory of Finite Groups. Academic Press, New York (1976) Köhler, C., Pahlings, H.: Regular orbits and the \(k(GV)\)-problem. In: Kantor, W.M., Seress, Á. (eds.) Groups and Computation III. Proceedings of the International Conference at the Ohio State University, June 15–19, (1999), pp. 209–228. Walter de Gruyter, Berlin (2001) Lewis, M.L.: Solvable groups whose degree graphs have two connected components. J. Group Theory 4, 255–275 (2001) Lewis, M.L.: An overview of graphs associated with character degrees and conjugacy class sizes in finite groups. Rocky Mt. J. Math. 38, 175–211 (2008) Lewis, M.L., Meng, Q.: Solvable groups whose prime divisor character degree graphs are 1-connected. Monatsh. Math. 190, 541–548 (2019) Lewis, M.L., White, D.L.: Connectedness of degree graphs of nonsolvable groups. J. Algebra 266, 51–76 (2003) Liebeck, M.: The affine permutation groups of rank three. Proc. Lond. Math. Soc. 54, 477–516 (1987) Manz, O., Staszewski, R., Willems, W.: On the number of components of a graph related to character degrees. Proc. Amer. Math. Soc. 103, 31–37 (1988) Manz, O., Wolf, T.R.: Representations of Solvable Groups. Cambridge University Press, Cambridge (1993) Martineau, R.P.: On \(2\)-modular representations of the Suzuki groups. Amer. J. Math. 94, 55–72 (1972) Moretó, A., Tiep, P.H.: Prime divisors of character degrees. J. Group Theory 11, 341–356 (2008) Parker, C., Rowley, P.: Symplectic Amalgams. Springer, London (2002) White, D.L.: Degree graphs of simple groups. Rocky Mt. J. Math. 39, 1713–1739 (2009) White, D.L.: Character degrees of extensions of \(PSL_2(q)\) and \(SL_2(q)\). J. Group Theory 16, 1–33 (2013) Wilson, R.A.: The Finite Simple Groups. Springer-Verlag, London (2009) Zhang, J.: A note on character degrees of finite solvable groups. Commun. Algebra 9, 4249–4258 (2000)