English
Related papers

Related papers: The classification of 2-compact groups

200 papers

We describe simply connected compact exceptional simple Lie groups in very elementary way. We first construct all simply connected compact exceptional Lie groups G concretely. Next, we find all involutive automorphisms of G, and determine…

Differential Geometry · Mathematics 2009-02-04 Ichiro Yokota

A pointwise-elliptic subset of a topological group is one whose elements all generate relatively-compact subgroups. A connected locally compact group has a dense pointwise-elliptic subgroup if and only if it is an extension by a compact…

Group Theory · Mathematics 2025-06-27 Alexandru Chirvasitu

For a cyclic group $A$ and a connected Lie group $G$ with an $A$-module structure (with the additional conditions that $G$ is compact and the $A$-module structure on $G$ is 1-semisimple if $A\cong\ZZ$), we define the twisted Weyl group…

Group Theory · Mathematics 2007-05-23 Jinpeng An

We endow the diffeomorphism group of a paracompact (reduced) orbifold with the structure of an infinite dimensional Lie group modelled on the space of compactly supported sections of the tangent orbibundle. For a second countable orbifold,…

Group Theory · Mathematics 2015-03-11 Alexander Schmeding

We describe the full group of isometries of absolutely simple, compact, connected real Lie groups, of SO(4) and of U(n), endowed with suitable bi-invariant Riemannian metrics.

Differential Geometry · Mathematics 2021-06-14 Alberto Dolcetti , Donato Pertici

An \emph{affine subtorus} of the compact torus $T=(S^1)^n$ is a translated copy of a Lie subgroup. Given a finite collection $T_1,\ldots, T_k$ of such subtori, and a prime $p$, we describe an explicit chain complex that calculates the group…

Algebraic Topology · Mathematics 2026-01-14 Alexey G. Gorinov , Alexander V. Zakharov

In [11] we showed that a loop in a simply connected compact Lie group $\dot{U}$ has a unique Birkhoff (or triangular) factorization if and only if the loop has a unique root subgroup factorization (relative to a choice of a reduced sequence…

Representation Theory · Mathematics 2017-07-05 Arlo Caine , Doug Pickrell

It was believed that modular data are enough to distinguish different modular categories (and topological orders in 2+1-dimensions). Then counterexamples to this conjecture were found by Mignard and Schauenburg in 2017. In this work, we…

Strongly Correlated Electrons · Physics 2019-08-29 Xueda Wen , Xiao-Gang Wen

We provide a unified proof of all known examples of locally compact groups that enjoy the Howe-Moore property, namely, the vanishing at infinity of all matrix coefficients of the group unitary representations that are without non-zero…

Representation Theory · Mathematics 2014-07-22 Corina Ciobotaru

We provide characterizations of Lie groups as compact-like groups in which all closed zero-dimensional metric (compact) subgroups are discrete. The "compact-like" properties we consider include (local) compactness, (local)…

General Topology · Mathematics 2018-03-05 Dikran Dikranjan , Dmitri Shakhmatov

In this paper, we introduce the concept of the independence graph of a directed 2-complex. We show that the class of diagram groups is closed under graph products over independence graphs of rooted 2-trees. This allows us to show that a…

Group Theory · Mathematics 2007-05-23 Victor Guba , Mark Sapir

The discrete cocompact subgroups of the five-dimensional connected, simply connected nilpotent Lie groups are determined up to isomorphism. Moreover, we prove if $G=N\times A$ is a connected, simply connected, nilpotent Lie group with an…

Group Theory · Mathematics 2009-02-18 Amira Ghorbel , Hatem Hamrouni

The rank rk(G) of a profinite group G is the supremum of d(H), where H ranges over all closed subgroups of G and d(H) denotes the minimal cardinality of a topological generating set for H. A compact topological group G admits the structure…

Group Theory · Mathematics 2011-01-06 B. Klopsch

Here we analyze a proper 2-generated core in a minimal counter example to the Cherlin-Zilber Algebraicity Conjecture for simple groups of finite Morley rank. We ultimately show that such a group is strongly embedded and the ambiant group is…

Group Theory · Mathematics 2014-02-26 Alexandre Borovik , Jeffrey Burdges , Ali Nesin

We describe an interesting relation between Lie 2-algebras, the Kac-Moody central extensions of loop groups, and the group $\mathrm{String}(n)$. A Lie 2-algebra is a categorified version of a Lie algebra where the Jacobi identity holds up…

Quantum Algebra · Mathematics 2023-05-16 John C. Baez , Alissa S. Crans , Danny Stevenson , Urs Schreiber

We show that every dense subgroup of a connected Lie group G contains a dense subgroup generated by 2d elements, where d=dim(G). We also give a detailed proof for the quantitive characterization of a contracting projective transformation in…

Group Theory · Mathematics 2026-05-21 Emmanuel Breuillard , Tsachik Gelander

A classical theorem of Drinfel'd states that the category of simply connected Poisson Lie groups H is isomorphic to the category of Manin triples (d, g, h), where h is the Lie algebra of H. In this paper, we consider Dirac Lie groups, that…

Differential Geometry · Mathematics 2017-06-14 David Li-Bland , Eckhard Meinrenken

Dwyer, Miller and Wilkerson proved that at the prime 2, the classifying spaces of SU(2) and SO(3) can be obtained as a homotopy pushout of the classifying spaces of certain subgroups. In this paper we show explicitly how these…

Algebraic Topology · Mathematics 2020-04-17 Eva Belmont , Natàlia Castellana , Jelena Grbić , Kathryn Lesh , Michelle Strumila

We classify two classes of B_2-graded Lie algebras which have a second compatible grading by an abelian group A: (a) graded-simple Lie algebras for A torsion-free and (b) division-A-graded Lie algebras. Our results describe the centreless…

Rings and Algebras · Mathematics 2013-12-17 Erhard Neher , Maribel Tocón

Riera proved at arXiv:1412.6964 that the diffeomorphism group of particular compact manifolds are not Jordan by exhibiting subgroups isomorphic to extra-special $p$-groups of exponent $p$ for primes $p$ satisfying some conditions.…

Differential Geometry · Mathematics 2019-12-24 Dávid R. Szabó