MSC: Primary 20C20; Secondary 16D90, 20C05
DOI: 10.21538/0134-4889-2021-27-1-220-239
Full text
This paper is based on the results of the 2020 Ural Workshop on Group Theory and Combinatorics.
We classify the Morita equivalence classes of principal blocks with elementary abelian defect groups of order 64 with respect to a complete discrete valuation ring with an algebraically closed residue field of characteristic two.
Keywords: Donovan’s conjecture, finite groups, Morita equivalence, block theory, modular representation theory
REFERENCES
1. Alperin J.L. Local representation theory. Ser. Cambridge Studies in Advanced mathematics, vol. 11. Cambridge: Cambridge University Press, 1986, 178 p. ISBN: 0521306604 .
2. Ardito C.G. Morita equivalence classes of blocks with elementary abelian defect groups of order 32. 2019. 32 p. Available on arXiv:1908.02652 .
3. Ardito C.G. Blocks with an elementary abelian defect group in characteristic two, PhD Thesis, University of Manchester, 2020. 256 p.
4. Boltje R., Kessar R., Linckelmann M. On Picard groups of blocks of finite groups. J. Algebra, 2020, vol. 558, pp. 70–101. doi: 10.1016/j.jalgebra.2019.02.045
5. Bosma W., Cannon J.J., Fieker C., Steel A. Handbook of Magma functions, edition 2.16. 2010.
6. Craven D., Eaton C.W., Kessar R. and Linckelmann M. The structure of blocks with a Klein four defect group. Math. Z., 2011, vol. 268, no. 1, pp. 441–476.
7. Craven D., Rouquier R. Perverse equivalences and Broue’s conjecture. Advances in Mathematics, 2013, vol. 248, pp. 1–58. doi: 10.1016/j.aim.2013.07.010
8. Eaton C.W., Kessar R., KЈulshammer B.K and Sambale B. 2-blocks with abelian defect groups. Advances in Mathematics, 2014, vol. 254, pp. 706–735. doi: 10.1016/j.aim.2013.12.024
9. Eaton C.W. Morita equivalence classes of 2-blocks of defect three. Proc. American Math. Soc., 2016, vol. 144, pp. 1961–1970.
10. Eaton C.W. Morita equivalence classes of blocks with elementary abelian defect groups of order 16. 2017. 17 p. Available on arXiv:1612.03485 .
11. Eaton C.W., Livesey M. Some examples of Picard groups of blocks. J. Algebra, 2020, vol. 558, pp. 350–370. doi: 10.1016/j.jalgebra.2019.08.004
12. Eaton C.W., Livesey M. Donovan’s conjecture and blocks with abelian defect groups. Proc. American Math. Soc., 2019, vol. 147, no. 3, pp. 963–970. doi: 10.1090/proc/14316
13. Eaton C.W., Eisele F., Livesey M. Donovan’s conjecture, blocks with abelian defect groups and discrete valuation rings. Math. Z., 2020, vol. 295, no. 1, pp. 249–264. doi: 10.1007/s00209-019-02354-1
14. Eaton C.W. et al. Block library [e-resource]. 2019. Available on https://wiki.manchester.ac.uk/blocks/
15. Eisele F. On the geometry of lattices and finiteness of Picard groups. 2019. 12 p. Available on arXiv:1908.00129 .
16. Erdmann K. Blocks whose defect groups are Klein four groups: a correction. J. Algebra, 1982, vol. 76, no. 2, pp. 505–518. doi: 10.1016/0021-8693(82)90228-9
17. Fong P., Harris M.E. On perfect isometries and isotypies in finite groups. Invent Math., 1993, vol. 114, no. 1, pp. 139–191. doi: 10.1007/BF01232665
18. Kessar R., Koshitani S., Linckelmann M. Conjectures of Alperin and Broue for 2-blocks with elementary abelian defect groups of order 8. Journal fur die reine und angewandte Mathematik, 2012, vol. 671, pp. 85–130. doi: 10.1515/CRELLE.2011.162
19. Kulshammer B. Crossed products and blocks with normal defect groups. Communications in Algebra, 1985, vol. 13, pp. 147–168. doi: 10.1080/00927878508823154
20. Kulshammer B. Donovan’s conjecture, crossed products and algebraic group actions. Israel J. Math., 1995, vol. 92, no. 1, pp. 295–306. doi: 10.1007/BF02762084
21. Kulshammer B., Puig L. Extensions of nilpotent blocks. Invent. Math., 1990, vol. 102, pp. 17–71. doi: 10.1007/BF01233419
22. Linckelmann M. The source algebras of blocks with a Klein four defect group. J. Algebra, 1994, vol. 167, no. 3, pp. 821–854. doi: 10.1006/jabr.1994.1214
23. Linckelmann M. The block theory of finite group algebras, vol. 1 and 2. London Mathematical Society Student Texts, vol. 91–92. Cambridge: Cambridge University Press, 2018. 1114 p. ISBN: 978-1108441902 .
24. Linckelmann M. On automorphisms and focal subgroups of blocks. In: Carlson J., Iyengar S., Pevtsova J. (eds), Geometric and Topological Aspects of the Representation Theory of Finite Groups, 2018, Springer Proceedings in Mathematics & Statistics, vol. 242, Cham: Springer, pp. 235–249. doi: 10.1007/978-3-319-94033-5_9
25. Livesey M. On Picard groups of blocks with normal defect groups. 2019. 28 p. Available on arXiv:1907.12167 .
26. McKernon E. 2-Blocks whose defect group is homocyclic and whose inertial quotient contains a Singer cycle. J. Algebra, 2020, vol. 563, pp. 30–48. doi: 10.1016/j.jalgebra.2020.06.029
27. Murai M. On blocks of normal subgroups of finite groups. Osaka J. Math., 2013, vol. 50, pp. 1007–1020.
28. Puig L. Nilpotent blocks and their source algebras. Invent. Math., 1988, vol. 93, no. 1, pp. 77–116. doi: 10.1007/BF01393688
29. Puig L., Usami Y. Perfect isometries for blocks with abelian defect groups and Klein four inertial quotients. J. Algebra, 1993, vol. 160, no. 1, pp. 192–225. doi: 10.1006/jabr.1993.1184
30. Puig L. Nilpotent extensions of blocks. Math. Z., 2011, vol. 269, no. 1, pp. 115–136. doi: 10.1007/s00209-010-0718-1
31. Usami Y. Perfect isometries for principal Blocks with abelian defect groups and elementary abelian 2-inertial quotients. J. Algebra, 1997, vol. 196, no. 2, pp. 646–681. doi: 10.1006/jabr.1997.7094
32. Ward H.N. On Ree’s series of simple groups. Transactions American Math. Soc., 1966, vol. 121, no. 1, pp. 62–89. doi: 10.2307/1994333
33. Walter J.H. The characterization of finite groups with abelian Sylow 2-subgroups. Annals Math., 1969, vol. 89, no. 3, pp. 405–514. doi: 10.2307/1970648
34. Zhou Y. On the p′–extensions of inertial blocks. Proc. American Math. Soc., 2016, vol. 144, no. 1, pp. 41–54. doi: 10.1090/proc/12691
Received September 6, 2020
Revised October 1, 2020
Accepted October 5, 2020
Funding Agency: This paper is part of the work done by the author during his PhD at the University of Manchester, supported by a Manchester Research Scholar Award and a President’s Doctoral Scholar Award.
Cesare Giulio Ardito, Department of Mathematics, City University of London, Northampton Square, London, EC1V 0HB, United Kingdom, email: cesareg.ardito@gmail.com
Cite this article as: Cesare Giulio Ardito, Morita equivalence classes of principal blocks with elementary abelian defect groups of order 64, Trudy Instituta Matematiki i Mekhaniki UrO RAN, 2021, vol. 27, no. 1, pp. 220–239.
Русский
Ч.Дж. Ардито. Классы Морита-эквивалентности главных блоков с элементарными абелевыми дефектными группами порядка 64
Дана классификация классов Морита-эквивалентности главных блоков с элементарными абелевыми дефектными группами порядка 64 относительно полного кольца дискретного нормирования с алгебраически замкнутым полем вычетов характеристики 2.
Ключевые слова: гипотеза Донована, конечные группы, Морита-эквивалентность, теория блоков, теория модулярных представлений