Browsing by MSC "20"
Now showing items 21-40 of 161
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The Character Triple Conjecture for Maximal Defect Characters and the Prime 2
[OWP-2023-15] (Mathematisches Forschungsinstitut Oberwolfach, 2023-08-22)We prove that Späth’s Character Triple Conjecture holds for every finite group with respect to maximal defect characters at the prime 2. This is done by reducing the maximal defect case of the conjecture to the so-called ... -
Cocharacter-closure and spherical buildings
[OWP-2015-12] (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)Let $k$ be a field, let $G$ be a reductive $k$-group and $V$ an affine $k$-variety on which $G$ acts. In this note we continue our study of the notion of cocharacter-closed $G(k)$-orbits in $V$. In earlier work we used a ... -
Cocharacter-Closure and the Rational Hilbert-Mumford Theorem
[OWP-2014-16] (Mathematisches Forschungsinstitut Oberwolfach, 2014-12-20)For a field $k$, let $G$ be a reductive $k$-group and $V$ an affine $k$-variety on which $G$ acts. Using the notion of cocharacter-closed $G(k)$-orbits in $V$ , we prove a rational version of the celebrated Hilbert-Mumford ... -
1823b - Cohomological and Metric Properties of Groups of Homeomorphisms of R
[OWR-2018-26] (2018) - (03 Jun - 09 Jun 2018)In recent years, the family of groups sharing features or design principles with classical Thompson groups has grown considerably. The workshop highlights new developments in this field with special emphasis on algorithmic ... -
1519 - Cohomology of Finite Groups: Interactions and Applications
[OWR-2015-24] (2015) - (03 May - 09 May 2015)The cohomology of finite groups is an important tool in many subjects including representation theory and algebraic topology. This meeting was the fourth in a series that has emphasized the interactions of group cohomology ... -
0536 - Cohomology of Finite Groups: Interactions and Applications
[OWR-2005-42] (2005) - (04 Sep - 10 Sep 2005)This is a report on a meeting on interactions and applications of the cohomology of finite groups. Besides several talks on the cohomology of finite groups there were talks on related subjects, in particular on the cohomology ... -
1030 - Cohomology of Finite Groups: Interactions and Applications
[OWR-2010-32] (2010) - (25 Jul - 31 Jul 2010)The cohomology of finite groups is an important tool in many subjects including representation theory and algebraic topology. This meeting was the third in a series that has emphasized the interactions of group cohomology ... -
2033 - Cohomology of Finite Groups: Interactions and Applications (hybrid meeting)
[OWR-2020-23] (2020) - (09 Aug - 15 Aug 2020)The cohomology of finite groups is an important tool in many subjects including representation theory and algebraic topology. This meeting was the fifth in a series that has emphasized the interactions of group ... -
1012 - Combinatorial Representation Theory
[OWR-2010-15] (2010) - (21 Mar - 27 Mar 2010)The workshop brought together researchers from different fields in representation theory and algebraic combinatorics for a fruitful interaction. New results, methods and developments ranging from classical and modular ... -
1631 - Computational Group Theory
[OWR-2016-37] (2016) - (31 Jul - 06 Aug 2016)This was the seventh workshop on Computational Group Theory. It showed that Computational Group Theory has significantly expanded its range of activities. For example, symbolic computations with groups and their representations ... -
0627 - Computational Group Theory
[OWR-2006-30] (2006) - (02 Jul - 08 Jul 2006)This workshop on Computational Group Theory revealed the close connections between its main themes “finitely presented groups”, “permutation groups”, “matrix groups” and “representations of groups”. The meeting also presented ... -
1131 - Computational Group Theory
[OWR-2011-37] (2011) - (31 Jul - 06 Aug 2011)This sixth workshop on Computational Group Theory proved that its main themes “finitely presented groups”, “$p$-groups”, “matrix groups” and “representations of groups” are lively and active fields of research. The talks ... -
Computing Congruence Quotients of Zariski Dense Subgroups
[OWP-2018-22] (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-26)We obtain a computational realization of the strong approximation theorem. That is, we develop algorithms to compute all congruence quotients modulo rational primes of a finitely generated Zariski dense group $H \leq ... -
Congruences Associated with Families of Nilpotent Subgroups and a Theorem of Hirsch
[OWP-2019-16] (Mathematisches Forschungsinstitut Oberwolfach, 2019-05-27)Our main result associates a family of congruences with each suitable system of nilpotent subgroups of a finite group. Using this result, we complete and correct the proof of a theorem of Hirsch concerning the class number ... -
A construction of hyperbolic Coxeter groups
[OWP-2010-04] (Mathematisches Forschungsinstitut Oberwolfach, 2010)We give a simple construction of Gromov hyperbolic Coxeter groups of arbitrarily large virtual cohomological dimension. Our construction provides new examples of such groups. Using this one can construct e.g. new groups ... -
Deciding Non-Freeness of Rational Möbius Groups
[OWP-2022-07] (Mathematisches Forschungsinstitut Oberwolfach, 2022-03-22)We explore a new computational approach to a classical problem: certifying non-freeness of (2-generator, parabolic) Möbius subgroups of SL(2, $\mathbb{Q}$). The main tools used are algorithms for Zariski dense groups and ... -
0931 - Differentialgeometrie im Großen
[OWR-2009-35] (2009) - (26 Jul - 01 Aug 2009)The meeting continued the biannual conference series Differentialgeometrie im Großen at the MFO which was established in the 60’s by Klingenberg and Chern. Global Riemannian geometry with its connections to geometric analysis, ... -
Edifices: Building-like Spaces Associated to Linear Algebraic Groups; In memory of Jacques Tits
[OWP-2023-04] (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)Given a semisimple linear algebraic $k$-group $G$, one has a spherical building $Δ_G$, and one can interpret the geometric realisation $Δ_G(\mathbb R)$ of $Δ_G$ in terms of cocharacters of $G$. The aim of this paper is to ... -
Embedding Spaces of Split Links
[OWP-2022-13] (Mathematisches Forschungsinstitut Oberwolfach, 2022-08-01)We study the homotopy type of the space $\mathcal{E}(L)$ of unparametrised embeddings of a split link $L=L_1\sqcup \ldots \sqcup L_n$ in $\mathbb{R}^3$. Inspired by work of Brendle and Hatcher, we introduce a semi-simplicial ... -
0911 - Enveloping Algebras and Geometric Representation Theory
[OWR-2009-15] (2009) - (08 Mar - 14 Mar 2009)The meeting brought together experts investigating Lie theory from the geometric, algebraic and combinatorial points of view to discuss recent progress and bring forward the research in this area by fostering scientific ...