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Small Defect Groups

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Blocks of Finite Groups and Their Invariants

Part of the book series: Lecture Notes in Mathematics ((LNM,volume 2127))

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Abstract

We use the results from the previous chapters in order to gain complete information about blocks with small defect groups. We also make use of the Cartan method. As an outcome, we give a complete description of the 2-blocks of defect at most 4. Additionally, we investigate some of the defect groups of order 32. The main result shows that Brauer’s k(B)-Conjecture and Olsson’s Conjecture are true for every 2-block of defect at most 5. The former conjecture is also verified for the defect groups of order 27. Finally, we are able to classify all 2-blocks with minimal non-metacyclic defect groups.

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References

  1. Aschbacher, M., Kessar, R., Oliver, B.: Fusion Systems in Algebra and Topology. London Mathematical Society Lecture Note Series, vol. 391. Cambridge University Press, Cambridge (2011)

    Google Scholar 

  2. Berkovich, Y., Janko, Z.: Groups of Prime Power Order, vol. 2. de Gruyter Expositions in Mathematics, vol. 47. Walter de Gruyter GmbH & Co. KG, Berlin (2008)

    Google Scholar 

  3. Blackburn, N.: Generalizations of certain elementary theorems on p-groups. Proc. Lond. Math. Soc. (3) 11, 1–22 (1961)

    Google Scholar 

  4. Brauer, R.: On blocks and sections in finite groups. II. Am. J. Math. 90, 895–925 (1968)

    Article  MathSciNet  Google Scholar 

  5. Eaton, C.W., Kessar, R., Külshammer, B., Sambale, B.: 2-Blocks with abelian defect groups. Adv. Math. 254, 706–735 (2014)

    Article  MATH  MathSciNet  Google Scholar 

  6. Feit, W.: The Representation Theory of Finite Groups. North-Holland Mathematical Library, vol. 25. North-Holland Publishing, Amsterdam (1982)

    Google Scholar 

  7. Gluck, D.: Rational defect groups and 2-rational characters. J. Group Theory 14(3), 401–412 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  8. Hall, M., Jr., Senior, J.K.: The Groups of Order 2n (n ≤ 6). The Macmillan Co., New York (1964)

    MATH  Google Scholar 

  9. Hendren, S.: Extra special defect groups of order p 3 and exponent p. J. Algebra 313(2), 724–760 (2007)

    Google Scholar 

  10. Huppert, B.: Endliche Gruppen. I. Die Grundlehren der Mathematischen Wissenschaften, Band 134. Springer, Berlin (1967)

    Google Scholar 

  11. Kessar, R., Koshitani, S., Linckelmann, M.: Conjectures of Alperin and Broué for 2-blocks with elementary abelian defect groups of order 8. J. Reine Angew. Math. 671, 85–130 (2012)

    MATH  MathSciNet  Google Scholar 

  12. Kiyota, M.: On 3-blocks with an elementary abelian defect group of order 9. J. Fac. Sci. Univ. Tokyo Sect. IA Math. 31(1), 33–58 (1984)

    MATH  MathSciNet  Google Scholar 

  13. Külshammer, B.: On 2-blocks with wreathed defect groups. J. Algebra 64, 529–555 (1980)

    Article  MATH  MathSciNet  Google Scholar 

  14. Külshammer, B., Sambale, B.: The 2-blocks of defect 4. Represent. Theory 17, 226–236 (2013)

    Article  MATH  MathSciNet  Google Scholar 

  15. Landrock, P.: On the number of irreducible characters in a 2-block. J. Algebra 68(2), 426–442 (1981)

    Article  MATH  MathSciNet  Google Scholar 

  16. Linckelmann, M.: Fusion category algebras. J. Algebra 277(1), 222–235 (2004)

    Article  MATH  MathSciNet  Google Scholar 

  17. Naik, V.: Groups of order 32 (2013). http://groupprops.subwiki.org/wiki/Groups_of_order_32

  18. Ninomiya, Y.: Finite p-groups with cyclic subgroups of index p 2. Math. J. Okayama Univ. 36, 1–21 (1994)

    MATH  MathSciNet  Google Scholar 

  19. O’Brien, E.A.: Hall-senior number vs small group id (2014). http://permalink.gmane.org/gmane.comp.mathematics.gap.user/2426

  20. Puig, L., Usami, Y.: Perfect isometries for blocks with abelian defect groups and Klein four inertial quotients. J. Algebra 160(1), 192–225 (1993)

    Article  MATH  MathSciNet  Google Scholar 

  21. Puig, L., Usami, Y.: Perfect isometries for blocks with abelian defect groups and cyclic inertial quotients of order 4. J. Algebra 172(1), 205–213 (1995)

    Article  MATH  MathSciNet  Google Scholar 

  22. Robinson, G.R.: On Brauer’s k(B) problem. J. Algebra 147(2), 450–455 (1992)

    Article  MATH  MathSciNet  Google Scholar 

  23. Sambale, B.: Cartan matrices and Brauer’s k(B)-conjecture. J. Algebra 331, 416–427 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  24. Sambale, B.: Cartan matrices and Brauer’s k(B)-conjecture II. J. Algebra 337, 345–362 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  25. Sambale, B.: Further evidence for conjectures in block theory. Algebra Number Theory 7(9), 2241–2273 (2013)

    Article  MATH  MathSciNet  Google Scholar 

  26. Sambale, B.: Cartan matrices of blocks of finite groups (2014). http://www.minet.uni-jena.de/algebra/personen/sambale/matrices.pdf

  27. The GAP Group: GAP – Groups, Algorithms, and Programming, Version 4.6.5 (2013). http://www.gap-system.org

  28. Usami, Y.: On p-blocks with abelian defect groups and inertial index 2 or 3. I. J. Algebra 119(1), 123–146 (1988)

    Article  MATH  MathSciNet  Google Scholar 

  29. Usami, Y.: Perfect isometries and isotypies for blocks with abelian defect groups and the inertial quotients isomorphic to Z 3 ×Z 3. J. Algebra 182(1), 140–164 (1996)

    Article  MATH  MathSciNet  Google Scholar 

  30. van der Waall, R.W.: On p-nilpotent forcing groups. Indag. Math. (N.S.) 2(3), 367–384 (1991)

    Google Scholar 

  31. Watanabe, A.: On perfect isometries for blocks with abelian defect groups and cyclic hyperfocal subgroups. Kumamoto J. Math. 18, 85–92 (2005)

    MATH  MathSciNet  Google Scholar 

  32. Watanabe, A.: Appendix on blocks with elementary abelian defect group of order 9. In: Representation Theory of Finite Groups and Algebras, and Related Topics (Kyoto, 2008), pp. 9–17. Kyoto University Research Institute for Mathematical Sciences, Kyoto (2010)

    Google Scholar 

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Sambale, B. (2014). Small Defect Groups. In: Blocks of Finite Groups and Their Invariants. Lecture Notes in Mathematics, vol 2127. Springer, Cham. https://doi.org/10.1007/978-3-319-12006-5_13

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