Shigeo Kosnitani, Tetsuro Okuyama. The principal 3-blocks of the Mathieu group M_{12} and the special linear group SL_3(3) are derived equivalent. Preprint.
Shigeo
Koshitani. A reciprocity theorem of Robinson-Benson-Webb for finite-dimensional
symmetric algebras. To appear in Archiv der Mathematik
https://arxiv.org/pdf/2605.09380
Shigeo Koshitani, Ipek Tuvay：Recognion of Brauer indecompsability for a
Scott module. Journal of Algebra and its Applications 24 (25), no.1 Paper No.2550015.
9 pages
https://www.worldscientific.com/doi/10.1142/S021949882550015X
Shigeo Koshitani, Calorine Lassueur, Benjamin
Annals of Representation Theory 1, No.3 (2024), pp.439-463
Shigeo Koshitani, Caroline Lassueur, Benjamin Sambale,:
Splendid Morita equivalences for principal blocks with semidihedral defect
groups, Proceedings of the
American Mathematical Society 150 (2022), 41—53.
Shigeo Koshitani, Caroline Lassueur: Trivial source
endo-trivial modules for finite groups with a semi-dihedral Sylow 2-subgroup
subgroups , “Beitraege zur
Algebra und Geometrie / Contributions to Algebra and Geometry 63(2022), 233--246.
Shigeo Koshitani,
Ipek Tuvay: The Brauer indecomposability of Scott modules with wreath
2-group vertices , Rocky Mountain Journal of Mathematics 51
(2021), 1259--1280.
Shigeo Koshitani,
Caroline Lassueur:
Trivial
source characters in blocks with cyclic defect groups, Journal of Algebra 574 (2021), 375--408. .
Shigeo Koshitani, Ipek Tuvay: The Brauer indecomposability of
Scott modules with semidihedral vertex , Proceedings
of the Edinburgh Mathematical Society
64 (2021), 174—182. https://www.doi.org/10.1017/S0013091521000067
Shigeo Koshitani,
Caroline Lassueur:
Splendid Morita equivalences for principal 2-blocks with
generalised quaternion defect groups, Journal of Algebra 558 (2020), 523—533.
Shigeo Koshitani, Caroline
Lassueur: Splendid Morita equivalences for principal 2-blocks with
dihedral defect groups, Mathematische Zeitschrift 294（2020）639—666.
Shigeo Koshitani,
Ipek Tuvay: The Brauer indecomposability of Scott modules for the
quadratic group Qd(p) , Algebras and Representation Theory 22
(2019), 1387—1397.
Shigeo Koshitani,
Caroline Lassueur:
Simple modules in the Auslander-Reiten quivers of principal
blocks with abelian defect groups , Nagoya
Mathematical Journal, 235 (2019), 58--85
The results of X. Chen and J. Zeng on linear p-Brauer
characters, Journal of Discrete Mathematical Sciences and Cryptography
21 (2018), 1515--1517.
Shigeo Koshitani,
Juergen Mueller:
The projective
cover of the trivial representation for finite group of Lie type in defining
characteristic , Algebra Colloquium 24 (2017), 439--452.
Shigeo Koshitani, Britta Spaeth:
Journal of Group Theory 19 (2016), 771--813.
Shigeo Koshitani, Britta Spaeth: The inductive Alperin-McKay condition for 2-blocks with
cyclic defect groups , Archiv der Mathematik 106 (2016), 107--116.
Shigeo Koshitani, Caroline Lassueur: Endo-trivial
modules for finite groups with dihedral Sylow 2-subgroups , Journal of Group
Theory 19 (2016), 635--660.
Radha Kessar, Shigeo Koshitani and Markus Linckelmann,: On the Brauer
indecomposability of Scott module , Quarterly
Journal of Mathematics (Oxford Journal), 66 (2015), 895--903.
Radha Kessar, Shigeo Koshitani and Markus Linckelmann,: On symmetric
quotients of symmetric algebras , Journal of
Algebra, 442 (2015), 423--437.
Shigeo Koshitani, Caroline Lassueur: Endo-trivial
modules for finite groups with Klein-four Sylow 2-subgroups , manuscripta
mathematica, 148 (2015), 265--282.
Shigeo Koshitani, Britta Spaeth: Cllifford theory
of characters in induced blocks , Proceedings of
the American Mathematical Society, 143 (2015), 3687--3702.
Shigeo Koshitani: Finite
groups whose first Cartan invariants over a field of characteristic two are two
, Journal of Algebra, 426 (2015), 259--272.
Shigeo Koshitani, Juergen Mueller and Felix Noeske: Broue's abelian
defect group conjecture and 3-decomposition numbers of the sporadic simple
Conway group Co_1 , Journal of Pure and Applied Algebra, 219 (2015), 142--160.
Shigeo Koshitani: On
the projective cover of the trivial module over a group agebra of a finite
group, Communications in Algebra 42 (2014), 4308-4321
Shigeo Koshitani, Burkhard Kueshammer, Benjamin Sambale: On the Loewy lengths of blocks , Mathematical
Proceedings of the Cambridge Philosophical Society 156 (2014), 555-570
Shigeo Koshitani, Juergen Mueller and Felix Noeske: Broue's abelian
defect group conjecture for the sporadic simple Janko group J4 revisited , Journal of
Agebra 398 (2014) 434--447
Shigeo Koshitani, Juergen Mueller and Felix Noeske: Broue's abelian defect
group conjecture holds for the double cover of the Higman-Sims sporadic simple
group , Journal of Agebra 376 (2013), 152--173
Radha Kessar, Shigeo Koshitani and Markus Linckelmann: Conjectures of Alperin
and Broue for 2-blocks with elementary abelian defect groups of order 8 ,
Journal fuer die reine und angewandte Mathematik (Crelle's Journal) 671 (2012),
85--130
Shigeo Koshitani, Juergen Mueller and Felix Noeske: Broue's abelian defect
group conjecture holds for the sporadic simple Conway group Co3 , Journal of
Agebra 348 (2011), 354--380
Shigeo Koshitani and Yutaka Yoshii: Eigenvaues of Cartan matrices of principal
3-bocks of finite groups with abelian Syow 3-subgroups Journal of Agebra 324
(2010) 1985--1993
Shigeo Koshitani and Juergen Mueller: Broue's abelian defect group conjecture
holds for the Harada-Norton sporadic simple group HN , Journal of Agebra 324
(2010) 394--429
Miles Holloway, Shigeo Koshitani and Naoko Kunugi: Blocks with nonabelian
defect groups which have cyclic subgroups of index p, , Archiv der Mathematik
94 (2010) 101--116
Shigeo Koshitani and Naoko Kunugi: Trivial source modues in blocks with cyclic
defect groups , Mathematische Zeitschrift 265 (2010) 161-172
Shigeo Koshitani, Naoko Kunugi and Katsushi Waki: Broue's abelian defect group
conjecture holds for the Janko simple group $J_4$ , Journal of Pure and Appied
Agebra 212 (2008) 1438-1456
Morton E. Harris and Shigeo Koshitani: An extension of Watanabe's theorem for
the Isaacs-Horimoto-Watanabe corresponding blocks , Journal of Agebra 296
(2006) 96--109
Shigeo Koshitani and Markus Linckemann: The Indecomposability of a certain
bimodule given by the Brauer construction , Journal of Agebra 285 (2005)
726-729
Shigeo Koshitani and Naoko Kunugi: Blocks of central p-group extensions ,
Proceedings of the American Mathematical Society 133 (2005) 21-26
Shigeo Koshitani, Naoko Kunugi and Katsushi Waki: Broue's abelian defect group
conjecture for the Held group and the sporadic Suzuki group , Journal of Agebra
279 (2004) 638-666