English
Related papers

Related papers: Quasi-connected reductive groups

200 papers

A Nash group is said to be almost linear if it has a Nash representation with finite kernel. Structures and basic properties of these groups are studied.

Representation Theory · Mathematics 2013-11-22 Binyong Sun

A connected algebraic group Q defined over a field of characteristic zero is quasi-reductive if there is an element of its dual of reductive type, that is such that the quotient of its stabiliser by the centre of Q is a reductive subgroup…

Representation Theory · Mathematics 2011-11-28 Anne Moreau , Oksana Yakimova

We give a method of constructing maps between tubular groups inductively according to a set of strategies. This map will be a quasi-isometry exactly when the set of strategies is consistent. Conversely, if there exists a quasi-isometry…

Group Theory · Mathematics 2010-07-20 Christopher H Cashen

We find surface subgroups in certain one-relator groups with torsion and use this to deduce a profinite criterion for a word in the free group to be primitive.

Group Theory · Mathematics 2025-10-03 Andrew Ng

We call a reductive complex group $G$ quasi-toral if $G^0$ is a torus. Let $G$ be quasi-toral and let $V$ be a faithful $1$-modular $G$-module. Let $N$ (the shell) be the zero fiber of the canonical moment mapping $\mu\colon V\oplus…

Symplectic Geometry · Mathematics 2025-01-24 Hans-Christian Herbig , Gerald W. Schwarz , Christopher Seaton

Given a connected linear algebraic group $G$, we descrive the subgroup of $G$ generated by all semisimple elements.

Group Theory · Mathematics 2024-12-17 Ivan Arzhantsev

We give a purely algebraic treatment of reduction theory for connections over the formal punctured disc. Our proofs apply to arbitrary connected linear algebraic groups over an algebraically closed field of characteristic 0. We also state…

Algebraic Geometry · Mathematics 2021-02-18 Andres Fernandez Herrero

We compute the Chow ring of a quasi-split geometrically almost simple algebraic group assuming the coefficients to be a field. This extends the classical computation for split groups done by Kac to the non-split quasi-split case. For the…

Algebraic Geometry · Mathematics 2024-10-08 Alexey Ananyevskiy , Nikita Geldhauser

We introduce a new algebraic concept of an algebra which is "almost" commutative (more precisely "quasi-commutative differential graded algebra" or ADGQ, in French). We associate to any simplicial set X an ADGQ - called D(X) - and show how…

Algebraic Topology · Mathematics 2007-05-23 Max Karoubi

We describe structure of quasihomomorphisms from arbitrary groups to discrete groups. We show that all quasihomomorphisms are 'constructible', i.e., are obtained via certain natural operations from homomorphisms to some groups and…

Group Theory · Mathematics 2015-07-09 Koji Fujiwara , Michael Kapovich

A topological group is (openly) almost-elliptic if it contains a(n open) dense subset of elements generating relatively-compact cyclic subgroups. We classify the (openly) almost-elliptic connected locally compact groups as precisely those…

Group Theory · Mathematics 2025-06-12 Alexandru Chirvasitu

A quasi-automatic semigroup is defined by a finite set of generators, a rational (regular) set of representatives, such that if a is a generator or neutral, then the graph of right multiplication by a on the set of representatives is a…

Group Theory · Mathematics 2019-06-12 Benjamin Blanchette , Christian Choffrut , Christophe Reutenauer

In this paper, we study some properties of homotopical closeness for paths. We define the quasi-small loop group as the subgroup of all classes of loops that are homotopically close to null-homotopic loops, denoted by $\pi_1^{qs} (X, x)$…

Algebraic Topology · Mathematics 2021-08-10 Mojtaba Moharreri , Behrooz Mashayekhy , Hanieh Mirebrahimi , Hamid Torabi , Ameneh Babaee

A relatively hyperbolic group $G$ is said to be QCERF if all finitely generated relatively quasiconvex subgroups are closed in the profinite topology on $G$. Assume that $G$ is a QCERF relatively hyperbolic group with double coset separable…

Group Theory · Mathematics 2025-04-02 Ashot Minasyan , Lawk Mineh

We give a self-contained introduction to linear algebraic and semialgebraic groups over real closed fields, and we generalize several key results about semisimple Lie groups to algebraic and semialgebraic groups over real closed fields. We…

Group Theory · Mathematics 2026-01-13 Raphael Appenzeller

In this note, we announce the first results on quasi-isometric rigidity of non-nilpotent polycyclic groups. In particular, we prove that any group quasi-isometric to the three dimenionsional solvable Lie group Sol is virtually a lattice in…

Group Theory · Mathematics 2007-05-23 Alex Eskin , David Fisher , Kevin Whyte

We use quasi-orders to describe the structure of C-groups. We do this by associating a quasi-order to each compatible C-relation of a group, and then give the structure of such quasi-ordered groups. We also reformulate in terms of…

Logic · Mathematics 2018-10-26 Gabriel Lehéricy

Let K be a discretly henselian field whose residue field is separably closed. Answering a question raised by G. Prasad, we show that a semisimple K-- group G is quasi-split if and only if it quasi--splits after a finite tamely ramified…

Group Theory · Mathematics 2017-07-12 Philippe Gille

This (quasi-)survey addresses the quasi-isometry classification of locally compact groups, with an emphasis on amenable hyperbolic locally compact groups. This encompasses the problem of quasi-isometry classification of homogeneous…

Group Theory · Mathematics 2020-05-05 Yves Cornulier

We investigate a slight weakening of the classical property of strong approximation, which we call almost strong approximation, for connected reductive algebraic groups over global fields with respect to special sets of valuations. While…

Algebraic Geometry · Mathematics 2026-01-13 Andrei S. Rapinchuk , Wojciech Tralle