Reflection groups | Geometry | Group theory

Complex reflection group

In mathematics, a complex reflection group is a finite group acting on a finite-dimensional complex vector space that is generated by complex reflections: non-trivial elements that fix a complex hyperplane pointwise. Complex reflection groups arise in the study of the invariant theory of polynomial rings. In the mid-20th century, they were completely classified in work of Shephard and Todd. Special cases include the symmetric group of permutations, the dihedral groups, and more generally all finite real reflection groups (the Coxeter groups or Weyl groups, including the symmetry groups of regular polyhedra). (Wikipedia).

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Symmetric groups

In this video we construct a symmetric group from the set that contains the six permutations of a 3 element group under composition of mappings as our binary operation. The specifics topics in this video include: permutations, sets, groups, injective, surjective, bijective mappings, onto

From playlist Abstract algebra

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Symmetric Groups (Abstract Algebra)

Symmetric groups are some of the most essential types of finite groups. A symmetric group is the group of permutations on a set. The group of permutations on a set of n-elements is denoted S_n. Symmetric groups capture the history of abstract algebra, provide a wide range of examples in

From playlist Abstract Algebra

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Visual Group Theory, Lecture 2.2: Dihedral groups

Cyclic groups describe the symmetry of objects that exhibit only rotational symmetry, like a pinwheel. Dihedral groups describe the symmetry of objects that exhibit rotational and reflective symmetry, like a regular n-gon. The corresponding dihedral group D_n has 2n elements: half are rota

From playlist Visual Group Theory

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Bireflections (Geometric Algebra 1.3)

In the third video of the series we need to have a chat about reflections. They are the atoms of transformations: a single reflection is a discrete transformation of space, but the product of two reflections is a continuous transformation. When the two reflections intersect they generate a

From playlist Bivector.net

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Physics 11.1.3a - Spherical and Parabolic Mirrors

Spherical and Parabolic mirrors. From the Physics course by Derek Owens. The distance learning class is available at www.derekowens.com

From playlist Physics - Reflection and Refraction

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Light and Optics 1_2 Introduction to Reflection

Reflection form plane and spherical mirrors

From playlist Physics - Light and Optics

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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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Visual Group Theory, Lecture 2.3: Symmetric and alternating groups

Visual Group Theory, Lecture 2.3: Symmetric and alternating groups In this lecture, we introduce the last two of our "5 families" of groups: (4) symmetric groups and (5) alternating groups. The symmetric group S_n is the group of all n! permutations of {1,...,n}. We see several different

From playlist Visual Group Theory

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Tathagata Basak: A monstrous(?) complex hyperbolic orbifold

I will report on progress with Daniel Allcock on the ”Monstrous Proposal”, namely the conjecture: Complex hyperbolic 13-space, modulo a particular discrete group, and with orbifold structure changed in a simple way, has fundamental group equal to (MxM)(semidirect)2, where M is the Monster

From playlist Topology

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John R. Parker: Complex hyperbolic lattices

Lattices in SU(2,1) can be viewed in several different ways: via their geometry as holomorphic complex hyperbolic isometries, as monodromy groups of hypergeometric functions, via algebraic geometry as ball quotients and (sometimes) using arithmeticity. In this talk I will describe these di

From playlist Geometry

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On Ultra-Parallel Complex Hyperbolic Triangle Groups by Anna Pratoussevitch

SURFACE GROUP REPRESENTATIONS AND GEOMETRIC STRUCTURES DATE: 27 November 2017 to 30 November 2017 VENUE:Ramanujan Lecture Hall, ICTS Bangalore The focus of this discussion meeting will be geometric aspects of the representation spaces of surface groups into semi-simple Lie groups. Classi

From playlist Surface Group Representations and Geometric Structures

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Group Definition (expanded) - Abstract Algebra

The group is the most fundamental object you will study in abstract algebra. Groups generalize a wide variety of mathematical sets: the integers, symmetries of shapes, modular arithmetic, NxM matrices, and much more. After learning about groups in detail, you will then be ready to contin

From playlist Abstract Algebra

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Geometric Categorifications of the Hecke Algebra - Laura Rider

2021 Women and Mathematics Colloquium Topic: Geometric Categorifications of the Hecke Algebra Speaker: Laura Rider Affiliation: University of Georgia Date: May 26, 2021 In the first part of this talk, I'll explain a geometric categorification of the Hecke algebra in terms of perverse sh

From playlist Mathematics

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Yuri Berest : Spaces of quasi-invariants

CONFERENCE Recording during the thematic meeting : « Chromatic Homotopy, K-Theory and Functors» the January 26, 2023 at the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Jean Petit Find this video and other talks given by worldwide mathematicians on CIR

From playlist Topology

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GT5. Index 2 Theorem and Dihedral Groups

EDIT: typo at 12:00, it should be "0 less than/equals k less than n", so as to include e and C. Abstract Algebra: We state and prove the Index Two Theorem for finding normal subgroup and list several examples. These include S3, A4, and the symmetry groups for the regular n-gon, D_2n.

From playlist Abstract Algebra

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Complex hyperbolic representations of triangle groups by John Parker

SURFACE GROUP REPRESENTATIONS AND GEOMETRIC STRUCTURES DATE: 27 November 2017 to 30 November 2017 VENUE:Ramanujan Lecture Hall, ICTS Bangalore The focus of this discussion meeting will be geometric aspects of the representation spaces of surface groups into semi-simple Lie groups. Classi

From playlist Surface Group Representations and Geometric Structures

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Vic Reiner, Lecture II - 11 February 2015

Vic Reiner (University of Minnesota) - Lecture II http://www.crm.sns.it/course/4036/ Many results in the combinatorics and invariant theory of reflection groups have q-analogues for the finite general linear groups GLn(Fq). These lectures will discuss several examples, and open questions

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

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Abstract Algebra | The dihedral group

We present the group of symmetries of a regular n-gon, that is the dihedral group D_n. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/

From playlist Abstract Algebra

Related pages

Klein four-group | Vector space | Binary icosahedral group | Hyperoctahedral group | Index of a subgroup | Group (mathematics) | Chevalley–Shephard–Todd theorem | Central product | Wreath product | Regular polyhedron | Hyperplane | Invariant theory | Symmetric group | Polynomial ring | Generalized symmetric group | Cartan matrix | Dihedral group | Klein quartic | Mathematics | Coxeter group | Valentiner group | Weyl group | Semidirect product | Hessian group | Mitchell's group | Cyclic group | Binary octahedral group | Extra special group | Binary tetrahedral group