Linear algebraic groups

Thin group (algebraic group theory)

In algebraic group theory, a thin group is a discrete Zariski-dense subgroup of G(R) that has infinite covolume, where G is a semisimple algebraic group over the reals. This is in contrast to a lattice, which is a discrete subgroup of finite covolume. The theory of "group expansion" (expander graph properties of related Cayley graphs) for particular thin groups has been applied to arithmetic properties of Apollonian circles and in Zaremba's conjecture. (Wikipedia).

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AlgTopReview4: Free abelian groups and non-commutative groups

Free abelian groups play an important role in algebraic topology. These are groups modelled on the additive group of integers Z, and their theory is analogous to the theory of vector spaces. We state the Fundamental Theorem of Finitely Generated Commutative Groups, which says that any such

From playlist Algebraic Topology

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Thin groups as monodromy groups, Part I - Jordan Ellenberg (University of Wisconsin-Madison)

Thin groups as monodromy groups Jordan Ellenberg University of Wisconsin – Madison We discuss various algebro-geometric contexts in which thin groups appear as monodromy groups attached to families of varieties over curves. http://www.msri.org/workshops/652/schedules/14578

From playlist Number Theory

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What is a Group? | Abstract Algebra

Welcome to group theory! In today's lesson we'll be going over the definition of a group. We'll see the four group axioms in action with some examples, and some non-examples as well which violate the axioms and are thus not groups. In a fundamental way, groups are structures built from s

From playlist Abstract Algebra

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Karen Vogtmann, Lecture I - 10 February 2015

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From playlist Algebraic topology, geometric and combinatorial group theory - 2015

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Group theory 32: Subgroups of free groups

This lecture is part of an online mathematics course on group theory. We describe subgroups of free groups, show that they are free, calculate the number of generators, and give two examples.

From playlist Group theory

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Michael Wibmer: Etale difference algebraic groups

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Algebraic and Complex Geometry

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Lie groups: Lie algebras

This lecture is part of an online graduate course on Lie groups. We define the Lie algebra of a Lie group in two ways, and show that it satisfied the Jacobi identity. The we calculate the Lie algebras of a few Lie groups. For the other lectures in the course see https://www.youtube.co

From playlist Lie groups

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Simple Groups - Abstract Algebra

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From playlist Abstract Algebra

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The Generalized Ramanujan Conjectures and Applications (Lecture 2) by Peter Sarnak

Lecture 2: Thin Groups and Expansion Abstract: Infinite index subgroups of matrix groups like SL(n,Z) which are Zariski dense in SL(n), arise in many geometric and diophantine problems (eg as reflection groups,groups connected with elementary geometry such as integral apollonian packings,

From playlist Generalized Ramanujan Conjectures Applications by Peter Sarnak

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Thin Matrix Groups - a brief survey of some aspects - Peter Sarnak

Speaker: Peter Sarnak (Princeton/IAS) Title: Thin Matrix Groups - a brief survey of some aspects More videos on http://video.ias.edu

From playlist Mathematics

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Karen Vogtmann, Lecture II - 12 February 2015

Karen Vogtmann (U. of Warwick, UK and Cornell University, USA) - Lecture II http://www.crm.sns.it/course/4037/ Automorphism groups of free groups bear similarities to both lattices in Lie groups and to surface mapping class groups. In this minicourse we will explore the cohomology of thes

From playlist Algebraic topology, geometric and combinatorial group theory - 2015

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Thin monodromy and Lyapunov exponents, via Hodge theory - Simion Filip

Analysis Seminar Topic: Thin monodromy and Lyapunov exponents, via Hodge theory Speaker: Simion Filip Affiliation: Harvard University Date: November 15, 2017 For more videos, please visit http://video.ias.edu

From playlist Mathematics

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Alexandru Buium 3/21/14 Part 3

Title: Arithmetic Differential Equations on GL(n)

From playlist Spring 2014

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Geordie Williamson: Miraculous Treumann-Smith theory and geometric Satake

Abstract: This talk will be about geometric approaches to the representation theory of reductive algebraic groups in positive characteristic p. A cornerstone of the geometric theory is the geometric Satake equivalence, which gives an incarnation of the category of representations as a cate

From playlist Geordie Williamson: Representation theory and the Geometric Satake

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Commensurators of thin Subgroups by Mahan M. J.

PROGRAM SMOOTH AND HOMOGENEOUS DYNAMICS ORGANIZERS: Anish Ghosh, Stefano Luzzatto and Marcelo Viana DATE: 23 September 2019 to 04 October 2019 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Ergodic theory has its origins in the the work of L. Boltzmann on the kinetic theory of gases.

From playlist Smooth And Homogeneous Dynamics

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D. Loughran - Sieving rational points on algebraic varieties

Sieves are an important tool in analytic number theory. In a typical sieve problem, one is given a list of p-adic conditions for all primes p, and the challenge is to count the number of integers which satisfy all these p-adic conditions. In this talk we present some versions of sieves for

From playlist Ecole d'été 2017 - Géométrie d'Arakelov et applications diophantiennes

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Thin Groups and Applications - Alex Kontorovich

Analysis and Beyond - Celebrating Jean Bourgain's Work and Impact May 21, 2016 More videos on http://video.ias.edu

From playlist Analysis and Beyond

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Semisimple $\mathbb{Q}$-algebras in algebraic combinatorics by Allen Herman

PROGRAM GROUP ALGEBRAS, REPRESENTATIONS AND COMPUTATION ORGANIZERS: Gurmeet Kaur Bakshi, Manoj Kumar and Pooja Singla DATE: 14 October 2019 to 23 October 2019 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Determining explicit algebraic structures of semisimple group algebras is a fund

From playlist Group Algebras, Representations And Computation

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Chapter 5: Quotient groups | Essence of Group Theory

Quotient groups is a very important concept in group theory, because it has paramount importance in group homomorphisms (connection with the isomorphism theorem(s)). With this video series, abstract algebra needs not be abstract - one can easily develop intuitions for group theory! In fac

From playlist Essence of Group Theory

Related pages

Algebraic group | Apollonian circles | Zariski topology | Lattice (group) | Real number | Expander graph | Cayley graph