Galois theory

Galois group

In mathematics, in the area of abstract algebra known as Galois theory, the Galois group of a certain type of field extension is a specific group associated with the field extension. The study of field extensions and their relationship to the polynomials that give rise to them via Galois groups is called Galois theory, so named in honor of Évariste Galois who first discovered them. For a more elementary discussion of Galois groups in terms of permutation groups, see the article on Galois theory. (Wikipedia).

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Visual Group Theory, Lecture 6.4: Galois groups

Visual Group Theory, Lecture 6.4: Galois groups The Galois group Gal(f(x)) of a polynomial f(x) is the automorphism group of its splitting field. The degree of a chain of field extensions satisfies a "tower law", analogous to the tower law for the index of a chain of subgroups. This hints

From playlist Visual Group Theory

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FIT4.1. Galois Group of a Polynomial

EDIT: There was an in-video annotation that was erased in 2018. My source (Herstein) assumes characteristic 0 for the initial Galois theory section, so separability is an automatic property. Let's assume that unless noted. In general, Galois = separable plus normal. Field Theory: We

From playlist Abstract Algebra

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Jean-Pierre Serre: How to prove that Galois groups are "large"

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 Number Theory

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Galois theory: Introduction

This lecture is part of an online course on Galois theory. This is an introductory lecture, giving an informal overview of Galois theory. We discuss some historical examples of problems that it was used to solve, such as the Abel-Ruffini theorem that degree 5 polynomials cannot in genera

From playlist Galois theory

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Galois theory: Infinite Galois extensions

This lecture is part of an online graduate course on Galois theory. We show how to extend Galois theory to infinite Galois extensions. The main difference is that the Galois group has a topology, and intermediate field extensions now correspond to closed subgroups of the Galois group. We

From playlist Galois theory

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Visual Group Theory, Lecture 6.1: Fields and their extensions

Visual Group Theory, Lecture 6.1: Fiends and their extensions This series of lectures is about Galois theory, which was invented by a French mathematician who tragically died in a dual at the age of 20. He invented the concept of a group to prove that there was no formula for solving degr

From playlist Visual Group Theory

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15 - Algorithmic aspects of the Galois theory in recent times

Orateur(s) : M. Singer Public : Tous Date : vendredi 28 octobre Lieu : Institut Henri Poincaré

From playlist Colloque Evariste Galois

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Counting Galois representations - Frank Calegari

Members' Seminar Topic:Counting Galois representations Speaker: Frank Calegari Affiliation: University of Chicago Date: November 4, 2016 For more video, visit http://video.ias.edu

From playlist Mathematics

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CTNT 2020 - Infinite Galois Theory (by Keith Conrad) - Lecture 3

The Connecticut Summer School in Number Theory (CTNT) is a summer school in number theory for advanced undergraduate and beginning graduate students, to be followed by a research conference. For more information and resources please visit: https://ctnt-summer.math.uconn.edu/

From playlist CTNT 2020 - Infinite Galois Theory (by Keith Conrad)

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CTNT 2020 - Infinite Galois Theory (by Keith Conrad) - Lecture 4

The Connecticut Summer School in Number Theory (CTNT) is a summer school in number theory for advanced undergraduate and beginning graduate students, to be followed by a research conference. For more information and resources please visit: https://ctnt-summer.math.uconn.edu/

From playlist CTNT 2020 - Infinite Galois Theory (by Keith Conrad)

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Jochen Koenigsmann : Galois codes for arithmetic and geometry via the power of valuation theory

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 Algebra

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Visual Group Theory, Lecture 6.5: Galois group actions and normal field extensions

Visual Group Theory, Lecture 6.5: Galois group actions and normal field extensions If f(x) has a root in an extension field F of Q, then any automorphism of F permutes the roots of f(x). This means that there is a group action of Gal(f(x)) on the roots of f(x), and this action has only on

From playlist Visual Group Theory

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Galois Groups Revisited - Chapter 25

This project was created with Explain Everything™ Interactive Whiteboard for iPad.

From playlist Modern Algebra - Chapter 25

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CTNT 2020 - Infinite Galois Theory (by Keith Conrad) - Lecture 2

Note: apologies for the (unknown) technical glitch in the image. The Connecticut Summer School in Number Theory (CTNT) is a summer school in number theory for advanced undergraduate and beginning graduate students, to be followed by a research conference. For more information and resource

From playlist CTNT 2020 - Infinite Galois Theory (by Keith Conrad)

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Visual Group Theory, Lecture 6.6: The fundamental theorem of Galois theory

Visual Group Theory, Lecture 6.6: The fundamental theorem of Galois theory The fundamental theorem of Galois theory guarantees a remarkable correspondence between the subfield lattice of a polynomial and the subgroup lattice of its Galois group. After illustrating this with a detailed exa

From playlist Visual Group Theory

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Kevin Buzzard (lecture 2/20) Automorphic Forms And The Langlands Program [2017]

Full course playlist: https://www.youtube.com/playlist?list=PLhsb6tmzSpiysoRR0bZozub-MM0k3mdFR http://wwwf.imperial.ac.uk/~buzzard/MSRI/ Summer Graduate School Automorphic Forms and the Langlands Program July 24, 2017 - August 04, 2017 Kevin Buzzard (Imperial College, London) https://w

From playlist MSRI Summer School: Automorphic Forms And The Langlands Program, by Kevin Buzzard [2017]

Related pages

Galois theory | Topological space | Klein four-group | Inverse limit | Finite field | Local field | Demushkin group | Automorphism | Topological group | Group (mathematics) | Isomorphism | Root of unity | Permutation group | Polynomial | Euler's totient function | Symmetric group | Rational number | Valuation (algebra) | Splitting field | Normal extension | Field extension | Mathematics | Set (mathematics) | Field (mathematics) | Global field | Fundamental theorem of Galois theory | Real number | Normal subgroup | Dihedral group of order 6 | Absolute Galois group | Order theory | Eisenstein's criterion | Cyclotomic polynomial | Irreducible polynomial | Abstract algebra | Complex number | Solvable group | Function composition | Galois extension | Profinite group | Kronecker–Weber theorem | Quaternion group