Undecidable problems | Group theory

Group isomorphism problem

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).

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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

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GT9. Group Isomorphisms

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

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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

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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

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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

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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

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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

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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

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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

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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

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10/13/17 Yuri Berest

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

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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

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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

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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

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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

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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

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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

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Group theory 3: Homomorphisms

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

Related pages

Decidability (logic) | Word problem for groups | Isomorphism | Abstract algebra | Group (mathematics) | Decision problem | Adian–Rabin theorem | Presentation of a group | Conjugacy problem