Undecidable problems | Group theory
In abstract algebra, the group isomorphism problem is the decision problem of determining whether two given finite group presentations refer to isomorphic groups. The isomorphism problem was formulated by Max Dehn, and together with the word problem and conjugacy problem, is one of three fundamental decision problems in group theory he identified in 1911. All three problems are undecidable: there does not exist a computer algorithm that correctly solves every instance of the isomorphism problem, or of the other two problems, regardless of how much time is allowed for the algorithm to run. In fact the problem of deciding whether a group is trivial is undecidable, a consequence of the Adian–Rabin theorem due to Sergei Adian and Michael O. Rabin. (Wikipedia).
Group Isomorphisms in Abstract Algebra
Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Group Isomorphisms in Abstract Algebra - Definition of a group isomorphism and isomorphic groups - Example of proving a function is an Isomorphism, showing the group of real numbers under addition is isomorphic to the group of posit
From playlist Abstract Algebra
Abstract Algebra: In analogy with bijections for sets, we define isomorphisms for groups. We note various properties of group isomorphisms and a method for constructing isomorphisms from onto homomorphisms. We also show that isomorphism is an equivalence relation on the class of groups.
From playlist Abstract Algebra
Lots of group isomorphism examples.
We present several examples of group homomorphisms and isomorphisms applying the first isomorphism theorem. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/
From playlist Abstract Algebra
Abstract Algebra | Group Isomorphisms
We give the definition of an isomorphism between groups and provide some examples. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/
From playlist Abstract Algebra
Homomorphisms in abstract algebra examples
Yesterday we took a look at the definition of a homomorphism. In today's lecture I want to show you a couple of example of homomorphisms. One example gives us a group, but I take the time to prove that it is a group just to remind ourselves of the properties of a group. In this video th
From playlist Abstract algebra
Chapter 6: Homomorphism and (first) isomorphism theorem | Essence of Group Theory
The isomorphism theorem is a very useful theorem when it comes to proving novel relationships in group theory, as well as proving something is a normal subgroup. But not many people can understand it intuitively and remember it just as a kind of algebraic coincidence. This video is about t
From playlist Essence of Group Theory
Homomorphisms in abstract algebra
In this video we add some more definition to our toolbox before we go any further in our study into group theory and abstract algebra. The definition at hand is the homomorphism. A homomorphism is a function that maps the elements for one group to another whilst maintaining their structu
From playlist Abstract algebra
A Natural Proof of the First Isomorphism Theorem (Group Theory)
The first isomorphism theorem is one of the most important theorems in group theory, but the standard proof may seem artificial, like every step of the proof is set up knowing that we're trying to create an isomorphism. In this video, we show an alternate proof with no such tricks using th
From playlist Group Theory
Global symmetry from local information: The Graph Isomorphism Problem – László Babai – ICM2018
Combinatorics | Mathematical Aspects of Computer Science Invited Lecture 13.4 | 14.5 Global symmetry from local information: The Graph Isomorphism Problem László Babai Abstract: Graph Isomorphism (GI) is one of a small number of natural algorithmic problems with unsettled complexity stat
From playlist Combinatorics
MathZero, The Classification Problem, and Set-Theoretic Type Theory - David McAllester
Seminar on Theoretical Machine Learning Topic: MathZero, The Classification Problem, and Set-Theoretic Type Theory Speaker: David McAllester Affiliation: Toyota Technological Institute at Chicago Date: May 14, 2020 For more video please visit http://video.ias.edu
From playlist Mathematics
Differential Isomorphism and Equivalence of Algebraic Varieties Board at 49:35 Sum_i=1^N 2/(x-phi_i(y,t))^2
From playlist Fall 2017
Rigidity for von Neumann algebras – Adrian Ioana – ICM2018
Analysis and Operator Algebras Invited Lecture 8.5 Rigidity for von Neumann algebras Adrian Ioana Abstract: We survey some of the progress made recently in the classification of von Neumann algebras arising from countable groups and their measure preserving actions on probability spaces.
From playlist Analysis & Operator Algebras
Martin Bridson - Profinite isomorphism problems.
Martin Bridson (University of Oxford, England)
From playlist T1-2014 : Random walks and asymptopic geometry of groups.
Structure of group rings and the group of units of integral group rings (Lecture 1) by Eric Jespers
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 fun
From playlist Group Algebras, Representations And Computation
Visual Group Theory, Lecture 4.1: Homomorphisms and isomorphisms
Visual Group Theory, Lecture 4.1: Homomorphisms and isomorphisms A homomoprhism is function f between groups with the key property that f(ab)=f(a)f(b) holds for all elements, and an isomorphism is a bijective homomorphism. In this lecture, we use examples, Cayley diagrams, and multiplicat
From playlist Visual Group Theory
GT10. Examples of Non-Isomorphic Groups
EDIT: Fix for 14:10: "Here's a quick way to fix. If y has order 3, then the order of yH divides 3. By assumption, yH has order 2, a contradiction. Recall that yH=H means y is in H. I'm actually overthinking the entire proof. Once we have H, pick any y not in H. Then yxy^-1=x^2.
From playlist Abstract Algebra
Bettina EICK - Computational group theory, cohomology of groups and topological methods 2
The lecture series will give an introduction to the computer algebra system GAP, focussing on calculations involving cohomology. We will describe the mathematics underlying the algorithms, and how to use them within GAP. Alexander Hulpke's lectures will being with some general computation
From playlist École d'Été 2022 - Cohomology Geometry and Explicit Number Theory
Alexander HULPKE - Computational group theory, cohomology of groups and topological methods 5
The lecture series will give an introduction to the computer algebra system GAP, focussing on calculations involving cohomology. We will describe the mathematics underlying the algorithms, and how to use them within GAP. Alexander Hulpke's lectures will being with some general computation
From playlist École d'Été 2022 - Cohomology Geometry and Explicit Number Theory
This is lecture 3 of an online mathematics course on group theory. It gives a review of homomorphisms and isomorphisms and gives some examples of these.
From playlist Group theory