English
Related papers

Related papers: Blocks with defect group D_{2^n} x C_{2^m}

200 papers

Let $G$ be a simple algebraic group over an algebraically closed field $K$ with Lie algebra $\mathfrak{g}$. For unipotent elements $u \in G$ and nilpotent elements $e \in \mathfrak{g}$, the Jordan block sizes of $\operatorname{Ad}(u)$ and…

Group Theory · Mathematics 2024-01-30 Mikko Korhonen

This article is the final one of a series of articles on certain blocks of modular representations of finite groups of Lie type and the associated geometry. We prove the conjecture of Brou\'e on derived equivalences induced by the complex…

Representation Theory · Mathematics 2012-04-10 Olivier Dudas , Raphaël Rouquier

We have previously shown that the isomorphism classes of orientable locally trivial fields of $C^*$-algebras over a compact metrizable space $X$ with fiber $D\otimes \mathbb{K}$, where $D$ is a strongly self-absorbing $C^*$-algebra, form an…

Operator Algebras · Mathematics 2019-10-03 Marius Dadarlat , Ulrich Pennig

In this paper, we prove that a \(p\)-block with abelian defect group is inertial if it covers a \(p\)-block of a normal subgroup of \(p\)-power index having only one irreducible Brauer character orbit.

Group Theory · Mathematics 2026-04-13 Fuming Jiang , Kun Zhang , Yuanyang Zhou

Relying on the classification of the indecomposable liftable modules in arbitrary blocks with non-trivial cyclic defect groups we give a complete classification of the trivial source modules lying in such blocks, describing in particular…

Representation Theory · Mathematics 2020-04-08 Gerhard Hiss , Caroline Lassueur

Let K be a complete discretely valued field with residue field k. If char(K) = 0, char(k) = 2 and the 2-rank of k is d, we prove that there exists an integer N depending on d such that the u-invariant of any function field in one variable…

Rings and Algebras · Mathematics 2014-04-15 R. Parimala , V. Suresh

We prove Turner's conjecture, which describes the blocks of the Hecke algebras of the symmetric groups up to derived equivalence as certain explicit Turner double algebras. Turner doubles are Schur-algebra-like `local' objects, which…

Representation Theory · Mathematics 2016-03-15 Anton Evseev , Alexander Kleshchev

Recently, there has been substantial progress on the Alperin weight conjecture. As a step to establish the Alperin weight conjecture for all finite groups, we prove the inductive blockwise Alperin weight condition for simple groups of…

Representation Theory · Mathematics 2019-08-12 Zhicheng Feng , Zhenye Li , Jiping Zhang

We classify the Morita equivalence classes of blocks with elementary abelian defect groups of order $16$ with respect to a complete discrete valuation ring with algebraically closed residue field of characteristic two. As a consequence,…

Group Theory · Mathematics 2019-05-16 Charles W. Eaton

We investigate the source algebra class of a p-block with cyclic defect groups of the group algebra of a finite group. By the work of Linckelmann this class is parametrized by the Brauer tree of the block together with a sign function on…

Group Theory · Mathematics 2022-08-01 Gerhard Hiss , Caroline Lassueur

For a quasi-projective smooth geometrically integral variety over a number field $k$, we prove that the iterated descent obstruction is equivalent to the descent obstruction. This generalizes a result of Skorobogatov, and this answers an…

Algebraic Geometry · Mathematics 2020-09-23 Yang Cao

The objective of this research paper is to study the relationship between a block of a finite group and a defect group of such block. We define a new notion which is called a strongly $k(D)$-block and give a necessary and sufficient…

Representation Theory · Mathematics 2014-09-25 Ahmad Alghamdi

We give a new proof for the description of the blocks in the category of representations of a reductive algebraic group $\mathbf{G}$ over a field of positive characteristic $\ell$ (originally due to Donkin), by working in the Satake…

Representation Theory · Mathematics 2026-04-02 Emilien Zabeth

In this paper, for n a positve integer, we compute the number of n degree representations for a dihedral group G of order 2m, m \geq 3 and the dimensions of the corresponding spaces of G invariant bilinear forms over a complex field C. We…

Group Theory · Mathematics 2021-03-03 Dilchand Mahto , Jagmohan Tanti

We prove that the number of irreducible ordinary characters in the principal $p$-block of a finite group $G$ of order divisible by $p$ is always at least $2\sqrt{p-1}$. This confirms a conjecture of H\'{e}thelyi and K\"{u}lshammer for…

Representation Theory · Mathematics 2023-05-31 Nguyen Ngoc Hung , A. A. Schaeffer Fry

In this paper, we prove Dahmen and Beukers' conjecture that the number of integral Lam\'{e} equations with index $n$ modulo scalar equivalence with the monodromy group dihedral $D_{N}$ of order $2N$ is given by \[L_{n}(N)=\frac{1}{2}\left(…

Number Theory · Mathematics 2021-05-12 Zhijie Chen , Ting-Jung Kuo , Chang-Shou Lin

The paper deals with the cohomological invariants of smooth and connected linear algebraic groups over an arbitrary field. More precisely, we study degree $2$ invariants with coefficients $\mathbb{Q}/\mathbb{Z}(1)$, that is invariants…

Algebraic Geometry · Mathematics 2025-09-30 Alexandre Lourdeaux

Let $p$ be a prime, $k$ an algebraic closure of $\mathbb{F}_p$ and $\Gamma$ the Galois group ${\rm Gal}(k/\mathbb{F}_p)$. Let $\mathcal{C}$ be a finite category and $\mathcal{O}_{\mathcal{C}}$ the $p$-orbit category of $\mathcal{C}$ defined…

Representation Theory · Mathematics 2026-05-08 Xin Huang

The inductive blockwise Alperin weight condition is a system of conditions whose verification for all non-abelian finite simple groups would imply the blockwise Alperin weight conjecture. We establish this condition for the groups $G_2(q)$,…

Representation Theory · Mathematics 2016-03-17 Elisabeth Schulte

Let k be an algebraically closed field of characteristic 2, and let W be the ring of infinite Witt vectors over k. Suppose G is a finite group and B is a block of kG with a dihedral defect group D such that there are precisely two…

Group Theory · Mathematics 2011-09-13 Frauke M. Bleher , Giovanna Llosent , Jennifer B. Schaefer