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Related papers: Isotypic blocks are functorially equivalent

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We obtain several results concerning the concept of isotypic structures. Namely we prove that any field of finite transcendence degree over a prime subfield is defined by types; then we construct isotypic but not isomorphic structures with…

Logic · Mathematics 2025-06-18 Pavel Gvozdevsky

The authors classify the finite index subgroups of R. Thompson's group $F$. All such groups that are not isomorphic to $F$ are non-split extensions of finite cyclic groups by $F$. The classification describes precisely which finite index…

Group Theory · Mathematics 2007-11-08 Collin Bleak , Bronlyn Wassink

We determine when an arithmetic subgroup of a reductive group defined over a global function field is of type FP_\infty by comparing its large-scale geometry to the large-scale geometry of lattices in real semisimple Lie groups.

Group Theory · Mathematics 2007-05-23 Kai-Uwe Bux , Kevin Wortman

In this paper we prove that there are exactly eight function fields, up to isomorphism, over finite fields with class number one.

Number Theory · Mathematics 2015-03-05 Pietro Mercuri , Claudio Stirpe

We introduce a new type of equivalence between blocks of finite group algebras called a strong isotypy. A strong isotypy is equivalent to a $p$-permutation equivalence and restricts to an isotypy in the sense of Brou\'{e}. To prove these…

Representation Theory · Mathematics 2023-10-18 John Revere McHugh

We describe the graded isomorphisms of rings of endomorphisms of graded flags over graded division algebras. As a consequence describe the isomorphism classes of upper block triangular matrix algebras (over an algebraically closed field of…

Rings and Algebras · Mathematics 2021-07-26 Alex Ramos , Claudemir Fidelis , Diogo Diniz

A characterization of multiplicative (and additive) arithmetical functions is given. Using this characterization, we show that the group of multiplicative arithmetical functions is isomorphic to the group of additive arithmetical functions.

Number Theory · Mathematics 2011-06-28 Masood Aryapoor

Let p and $\ell$ be two distinct primes, F a p-adic field and n an integer. We show that any level 0 block of the category of smooth Z $\ell$-valued representations of GL n (F) is equivalent to the unipotent block of an appropriate product…

Representation Theory · Mathematics 2016-03-24 Jean-François Dat

By results of Rognerud, a source algebra equivalence between two $p$-blocks of finite groups induces an equivalence between the categories of cohomological Mackey functors associated with these blocks, and a splendid derived equivalence…

Group Theory · Mathematics 2015-10-07 Markus Linckelmann

Let F be a non-Archimedean locally compact field of residue characteristic p, let G be an inner form of GL(n,F) with n>0, and let l be a prime number different from p. We describe the block decomposition of the category of finite length…

Representation Theory · Mathematics 2022-04-28 Bastien Drevon , Vincent Sécherre

We give a characterization of the sets of objects of the derived category of a block of a finite group algebra (or other symmetric algebra) that occur as the set of images of simple modules under an equivalence of derived categories. We…

Representation Theory · Mathematics 2007-05-23 Jeremy Rickard

In this paper we describe the blocks of the partition algebra over a field of positive characteristic.

Representation Theory · Mathematics 2015-01-22 C. Bowman , M. De Visscher , O. King

We introduce a new type of equivalence between blocks of finite group algebras called an almost isotypy. An almost isotypy restricts to a weak isotypy in Brou\'{e}'s original definition, and it is slightly weaker than Linckelmann's version.…

Representation Theory · Mathematics 2025-02-26 Xin Huang

We study algebraic and model-theoretic properties of existentially closed fields with an action of a fixed finite group. Such fields turn out to be pseudo-algebraically closed in a rather strong sense. We place this work in a more general…

Logic · Mathematics 2019-05-24 Daniel Max Hoffmann , Piotr Kowalski

In this note, we prove that the homotopy sequence of the algebraic fundamental group is exact if the base field is of characteristic 0.

Algebraic Geometry · Mathematics 2018-11-21 Lei Zhang

Let $F$ be a finitely generated regular field extension of transcendence degree $\geq 2$ over a perfect field $k$. We show that the multiplicative group $F^\times/k^\times$ endowed with the equivalence relation induced by algebraic…

Algebraic Geometry · Mathematics 2018-08-16 Anna Cadoret , Alena Pirutka

A simple criterion for a functor to be finitary is presented: we call $F$ finitely bounded if for all objects $X$ every finitely generated subobject of $FX$ factorizes through the $F$-image of a finitely generated subobject of $X$. This is…

Category Theory · Mathematics 2019-10-22 Jiří Adámek , Stefan Milius , Lurdes Sousa , Thorsten Wißmann

We prove that if open subgroups of the groups of invertible elements in two Fourier-Stieltjes algebras are isometric as metric spaces, then the underlying locally compact groups are topologically isomorphic. We describe the structure of…

Functional Analysis · Mathematics 2023-12-20 Osamu Hatori , Shiho Oi

Let $G$ be a finite group. In this paper, we first introduce a new notion, so-called the Mackey double category of $G$. Then we prove that the category of Mackey double categories and the category of Mackey functors of $G$ are equivalent.

Group Theory · Mathematics 2026-03-18 Mawei Wu

Let $X$ and $Y$ be nonsingular projective varieties over an algebraically closed field $k$ of positive characteristic. If $X$ and $Y$ are birational, we show their $S$-fundamental group schemes are isomorphic.

Algebraic Geometry · Mathematics 2010-06-29 Amit Hogadi , Vikram Mehta