Algebraic structures | Semigroup theory
In mathematics, a semigroup is a nonempty set together with an associative binary operation. A special class of semigroups is a class of semigroups satisfying additional properties or conditions. Thus the class of commutative semigroups consists of all those semigroups in which the binary operation satisfies the commutativity property that ab = ba for all elements a and b in the semigroup.The class of finite semigroups consists of those semigroups for which the underlying set has finite cardinality. Members of the class of Brandt semigroups are required to satisfy not just one condition but a set of additional properties. A large collection of special classes of semigroups have been defined though not all of them have been studied equally intensively. In the algebraic theory of semigroups, in constructing special classes, attention is focused only on those properties, restrictions and conditions which can be expressed in terms of the binary operations in the semigroups and occasionally on the cardinality and similar properties of subsets of the underlying set. The underlying sets are not assumed to carry any other mathematical structures like order or topology. As in any algebraic theory, one of the main problems of the theory of semigroups is the classification of all semigroups and a complete description of their structure. In the case of semigroups, since the binary operation is required to satisfy only the associativity property the problem of classification is considered extremely difficult. Descriptions of structures have been obtained for certain special classes of semigroups. For example, the structure of the sets of idempotents of regular semigroups is completely known. Structure descriptions are presented in terms of better known types of semigroups. The best known type of semigroup is the group. A (necessarily incomplete) list of various special classes of semigroups is presented below. To the extent possible the defining properties are formulated in terms of the binary operations in the semigroups. The references point to the locations from where the defining properties are sourced. (Wikipedia).
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"
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
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
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"
GT23. Composition and Classification
Abstract Algebra: We use composition series as another technique for studying finite groups, which leads to the notion of solvable groups and puts the focus on simple groups. From there, we survey the classification of finite simple groups and the Monster group.
From playlist Abstract Algebra
On the structure of quantum Markov semigroups - F. Fagnola - PRACQSYS 2018 - CEB T2 2018
Franco Fagnola (Department of Mathematics, Politecnico di Milano, Italy) / 06.07.2018 On the structure of quantum Markov semigroups We discuss the relationships between the decoherence-free subalgebra and the structure of the fixed point subalgebra of a quantum Markov semigroup on B(h) w
From playlist 2018 - T2 - Measurement and Control of Quantum Systems: Theory and Experiments
Concentration of quantum states from quantum functional (...) - N. Datta - Workshop 2 - CEB T3 2017
Nilanjana Datta / 24.10.17 Concentration of quantum states from quantum functional and transportation cost inequalities Quantum functional inequalities (e.g. the logarithmic Sobolev- and Poincaré inequalities) have found widespread application in the study of the behavior of primitive q
From playlist 2017 - T3 - Analysis in Quantum Information Theory - CEB Trimester
Group theory 24: Extra special groups
This lecture is part of an online mathematics course on group theory. It covers groups of order p^3. The non-abelian ones are examples of extra special groups, a sort of analog of the Heisenberg groups of quantum mechanics.
From playlist Group theory
Type Classes for Mathematical Formalizations in Coq - Matthieu Sozeau
Matthieu Sozeau INRIA Paris; Member, School of Mathematics October 3, 2012 For more videos, visit http://video.ias.edu
From playlist Mathematics
Group theory 20: Frobenius groups
This lecture is part of an online mathematics course on group theory. It gives several examples of Frobenius groups (permutation groups where any element fixing two points is the identity).
From playlist Group theory
"New Paradigms in Invariant Theory" - Roger Howe, Yale University [2011]
HKUST Institute for Advanced Study Distinguished Lecture New Paradigms in Invariant Theory Speaker: Prof Roger Howe, Yale University Date: 13/6/2011 Video taken from: http://video.ust.hk/Watch.aspx?Video=6A41D5F6B1A790DC
From playlist Mathematics
CU Boulder 2020 Mathematics Virtual Graduation Ceremony
Congratulations to the Mathematics Class of 2020
From playlist My Students
The General Linear Group, The Special Linear Group, The Group C^n with Componentwise Multiplication
Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys The General Linear Group, The Special Linear Group, The Group C^n with Componentwise Multiplication
From playlist Abstract Algebra
Workshop 1 "Operator Algebras and Quantum Information Theory" - CEB T3 2017 - A.Gheondea
Aurelian Gheondea (Bilkent University, Ankara) / 11.09.17 Title: Symmetry versus Conservation Laws in Dynamical Quantum Systems: A Unifying Approach through Propagation of Fixed Points Abstract: We unify recent Noether type theorems on the equivalence of symmetries with conservation laws
From playlist 2017 - T3 - Analysis in Quantum Information Theory - CEB Trimester
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
Volodymyr Nekrashevych: Contracting self-similar groups and conformal dimension
HYBRID EVENT Recorded during the meeting "Advancing Bridges in Complex Dynamics" the September 20, 2021 by the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Guillaume Hennenfent Find this video and other talks given by worldwide mathematicians on CIRM'
From playlist Dynamical Systems and Ordinary Differential Equations
Risk-sensitive control for diffusions with jumps by Anup Biswas
PROGRAM: ADVANCES IN APPLIED PROBABILITY ORGANIZERS: Vivek Borkar, Sandeep Juneja, Kavita Ramanan, Devavrat Shah, and Piyush Srivastava DATE & TIME: 05 August 2019 to 17 August 2019 VENUE: Ramanujan Lecture Hall, ICTS Bangalore Applied probability has seen a revolutionary growth in resear
From playlist Advances in Applied Probability 2019
Abstract Algebra: We define the notion of a subgroup and provide various examples. We also consider cyclic subgroups and subgroups generated by subsets in a given group G. Example include A4 and D8. U.Reddit course materials available at http://ureddit.com/class/23794/intro-to-group-
From playlist Abstract Algebra
Bernard Helffer: Spectral theory and semi-classical analysis for the complex Schrödinger operator
Abstract: We consider the operator Ah=−h2Δ+iV in the semi-classical limit h→0, where V is a smooth real potential with no critical points. We obtain both the left margin of the spectrum, as well as resolvent estimates on the left side of this margin. We extend here previous results obtaine
From playlist Mathematical Physics