Algebraic structures | Semigroup theory
In mathematics, a completely regular semigroup is a semigroup in which every element is in some subgroup of the semigroup. The class of completely regular semigroups forms an important subclass of the class of regular semigroups, the class of inverse semigroups being another such subclass. Alfred H. Clifford was the first to publish a major paper on completely regular semigroups though he used the terminology "semigroups admitting relative inverses" to refer to such semigroups. The name "completely regular semigroup" stems from Lyapin's book on semigroups. In the Russian literature, completely regular semigroups are often called "Clifford semigroups".In the English literature, the name "Clifford semigroup" is used synonymously to "inverse Clifford semigroup", and refers to a completely regular inverse semigroup.In a completely regular semigroup, each Green H-class is a group and the semigroup is the union of these groups. Hence completely regular semigroups are also referred to as "unions of groups". Epigroups generalize this notion and their class includes all completely regular semigroups. (Wikipedia).
Inner & Outer Semidirect Products Derivation - Group Theory
Semidirect products are a very important tool for studying groups because they allow us to break a group into smaller components using normal subgroups and complements! Here we describe a derivation for the idea of semidirect products and an explanation of how the map into the automorphism
From playlist Group Theory
Group theory 7: Semidirect products
This is lecture 7 of an online course on group theory. It covers semidirect products and uses them to classify groups of order 6.
From playlist Group theory
Normal Subgroups and Quotient Groups (aka Factor Groups) - Abstract Algebra
Normal subgroups are a powerful tool for creating factor groups (also called quotient groups). In this video we introduce the concept of a coset, talk about which subgroups are “normal” subgroups, and show when the collection of cosets can be treated as a group of their own. As a motivat
From playlist Abstract Algebra
Walter van Suijlekom: Semigroup of inner perturbations in Non Commutative Geometry
Starting with an algebra, we define a semigroup which extends the group of invertible elements in that algebra. As we will explain, this semigroup describes inner perturbations of noncommutative manifolds, and has applications to gauge theories in physics. We will present some elementary e
From playlist HIM Lectures: Trimester Program "Non-commutative Geometry and its Applications"
Before we carry on with our coset journey, we need to discover when the left- and right cosets are equal to each other. The obvious situation is when our group is Abelian. The other situation is when the subgroup is a normal subgroup. In this video I show you what a normal subgroup is a
From playlist Abstract algebra
Inner Semidirect Product Example: Dihedral Group
Semidirect products explanation: https://youtu.be/Pat5Qsmrdaw Semidirect products are very useful in group theory. To understand why, it's helpful to see an example. Here we show how to write the dihedral group D_2n as a semidirect product, and how we can describe that purely using cyclic
From playlist Group Theory
Joachim Cuntz: Semigroup C*-algebras and toric varieties
The lecture was held within the framework of the Hausdorff Trimester Program: K-Theory and Related Fields. The coordinate ring of a toric variety is the semigroup ring of a finitely generated subsemigroup of Zn. Such semigroups have the interesting feature that their family of constructib
From playlist HIM Lectures: Trimester Program "K-Theory and Related Fields"
EDIT: At 6:24, the product should be "(e sub H, e sub N)", not "(e sub H, e sub G)" Abstract Algebra: Using automorphisms, we define the semidirect product of two groups. We prove the group property and construct various examples, including the dihedral groups. As an application, we
From playlist Abstract Algebra
Zero dimensional valuations on equicharacteristic (...) - B. Teissier - Workshop 2 - CEB T1 2018
Bernard Teissier (IMJ-PRG) / 06.03.2018 Zero dimensional valuations on equicharacteristic noetherian local domains. A study of those valuations based, in the case where the domain is complete, on the relations between the elements of a minimal system of generators of the value semigroup o
From playlist 2018 - T1 - Model Theory, Combinatorics and Valued fields
Dirk Blömker: Modulation Equations for SPDEs on unbounded domains
The lecture was held within the of the Hausdorff Junior Trimester Program: Randomness, PDEs and Nonlinear Fluctuations. Abstract: We consider the approximation via modulation equations for nonlinear stochastic partial differential equations (SPDEs) like the stochastic Swift-Hohenberg (SH)
From playlist HIM Lectures: Junior Trimester Program "Randomness, PDEs and Nonlinear Fluctuations"
Courses - A. Kupiainen “Quantum Field Theory for Probabilists”
The course consists of two parts. In the first one we give an introduction to the Renormalization Group as a method to study quantum field theory and statistical mechanics models at critical temperature. In the second part we apply these ideas to proving existence and uniqueness of solutio
From playlist T1-2015 : Disordered systems, random spatial processes and some applications
Optimal Transportation and Applications - 14 November 2018
http://crm.sns.it/event/436 It is the ninth edition of this "traditional'' meeting in Pisa, after the ones in 2001, 2003, 2006, 2008, 2010, 2012, 2014 and 2016. Organizing Committee Luigi Ambrosio, Scuola Normale Superiore, Pisa Giuseppe Buttazzo, Dipartimento di Matematica, Università
From playlist Centro di Ricerca Matematica Ennio De Giorgi
CU Boulder 2020 Mathematics Virtual Graduation Ceremony
Congratulations to the Mathematics Class of 2020
From playlist My Students
Markus Haase : Operators in ergodic theory - Lecture 3 : Compact semigroups and splitting theorems
Abstract : The titles of the of the individual lectures are: 1. Operators dynamics versus base space dynamics 2. Dilations and joinings 3. Compact semigroups and splitting theorems Recording during the thematic meeting : "Probabilistic Aspects of Multiple Ergodic Averages " the December 8
From playlist Dynamical Systems and Ordinary Differential Equations
Charles Batty: Rates of decay associated with operator semigroups
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 Dynamical Systems and Ordinary Differential Equations
Emmanuel Trélat - Analyse spectrale des Laplaciens sous-Riemanniens, mesure de Weyl
Dans une série de travaux avec Yves Colin de Verdière et Luc Hillairet, nous étudions les propriétés spectrales des Laplaciens sous-Riemanniens, qui sont des opérateurs hypoelliptiques. L'objectif principal est d'obtenir des résultats d'ergodicité quantique, ce que nous avons fait en géo
From playlist Journée Sous-Riemannienne 2016
CEB T2 2017 - Fraydoun Rezakhanlou - 3/3
Fraydoun Rezakhanlou (Berkeley) - 09/06/2017 The lectures will discuss the following topics: 1. Scalar Conservation Laws and theirs Markovian solutions 2. Conservation laws with stochastic external force 3. Hamilton-Jacobi PDE, Hamiltonian ODEs and Mather Theory 4. Homogenization for
From playlist 2017 - T2 - Stochastic Dynamics out of Equilibrium - CEB Trimester
Categories 6 Monoidal categories
This lecture is part of an online course on categories. We define strict monoidal categories, and then show how to relax the definition by introducing coherence conditions to define (non-strict) monoidal categories. We finish by defining symmetric monoidal categories and showing how super
From playlist Categories for the idle mathematician
Adam Skalski: Translation invariant noncommutative Dirichlet forms
Talk by Adam Skalski in Global Noncommutative Geometry Seminar (Europe) http://www.noncommutativegeometry.nl/ncgseminar/ on April 28, 2021
From playlist Global Noncommutative Geometry Seminar (Europe)
(ML 19.5) Positive semidefinite kernels (Covariance functions)
Definition of a positive semidefinite kernel, or covariance function. A simple example. Explanation of terminology: autocovariance, positive definite kernel, stationary kernel, isotropic kernel, covariogram, positive definite function.
From playlist Machine Learning