Theorems in group theory | Galois theory

Fundamental theorem of Galois theory

In mathematics, the fundamental theorem of Galois theory is a result that describes the structure of certain types of field extensions in relation to groups. It was proved by Évariste Galois in his development of Galois theory. In its most basic form, the theorem asserts that given a field extension E/F that is finite and Galois, there is a one-to-one correspondence between its intermediate fields and subgroups of its Galois group. (Intermediate fields are fields K satisfying F ⊆ K ⊆ E; they are also called subextensions of E/F.) (Wikipedia).

Fundamental theorem of Galois theory
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FIT4.3. Galois Correspondence 1 - Examples

Field Theory: We define Galois extensions and state the Fundamental Theorem of Galois Theory. Proofs are given in the next part; we give examples to illustrate the main ideas.

From playlist Abstract Algebra

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Galois theory: Fundamental theorem of algebra

This lecture is part of an online graduate course on Galois theory. We use Galois theory to give a (mostly) algebraic proof that the complex numbers form an algebraically closed field.

From playlist Galois theory

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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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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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Calculus - The Fundamental Theorem, Part 1

The Fundamental Theorem of Calculus. First video in a short series on the topic. The theorem is stated and two simple examples are worked.

From playlist Calculus - The Fundamental Theorem of Calculus

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This lecture is part of an online graduate course on Galois theory. We prove the main theorem of Galois theory, given a bijection between subgroups of a Galois group and subextensions of a Galois extension. We illustrate it with the example of the splitting field of 4th roots of 2.

From playlist Galois theory

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We continue our historical introduction to the ideas of Galois and others on the fundamental problem of how to solve polynomial equations. In this video we focus on Galois' insights into how extending our field of coefficients, typically by introducing some radicals, the symmetries of the

From playlist MathHistory: A course in the History of Mathematics

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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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Galois theory gives a beautiful insight into the classical problem of when a given polynomial equation in one variable, such as x^5-3x^2+4=0 has solutions which can be expressed using radicals. Historically the problem of solving algebraic equations is one of the great drivers of algebra,

From playlist MathHistory: A course in the History of Mathematics

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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]

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Richard Taylor "Reciprocity Laws" [2012]

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Francis Brown - 4/4 Mixed Modular Motives and Modular Forms for SL_2 (\Z)

In the `Esquisse d'un programme', Grothendieck proposed studying the action of the absolute Galois group upon the system of profinite fundamental groups of moduli spaces of curves of genus g with n marked points. Around 1990, Ihara, Drinfeld and Deligne independently initiated the study of

From playlist Francis Brown - Mixed Modular Motives and Modular Forms for SL_2 (\Z)

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Kevin Buzzard (lecture 4/20) Automorphic Forms And The Langlands Program [2017]

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

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Introduction to p-adic Hodge theory (Lecture 1) by Denis Benois

PERFECTOID SPACES ORGANIZERS : Debargha Banerjee, Denis Benois, Chitrabhanu Chaudhuri and Narasimha Kumar Cheraku DATE & TIME : 09 September 2019 to 20 September 2019 VENUE : Madhava Lecture Hall, ICTS, Bangalore Scientific committee: Jacques Tilouine (University of Paris, France) Eknat

From playlist Perfectoid Spaces 2019

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Francis Brown - 1/4 Mixed Modular Motives and Modular Forms for SL_2 (\Z)

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From playlist Francis Brown - Mixed Modular Motives and Modular Forms for SL_2 (\Z)

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Winnie Li: Unramified graph covers of finite degree

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From playlist Women at CIRM

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The Fundamental Theorem of Calculus | Algebraic Calculus One | Wild Egg

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From playlist Algebraic Calculus One

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Galois theory | Topological space | Klein four-group | Inverse limit | Class field theory | Radical extension | Platonic solid | Automorphism | Kummer theory | Topological group | Index of a subgroup | Group (mathematics) | Modular lambda function | Permutation | Trivial group | Fixed-point subring | Symmetric group | Group isomorphism | Quotient group | Finite group | Splitting field | Abel–Ruffini theorem | Field extension | Normal extension | Projective line | Mathematics | Set (mathematics) | Field (mathematics) | Normal subgroup | J-invariant | Complex conjugate | Galois group | Eisenstein's criterion | Galois connection | Subgroup | Solvable group | Galois extension | Profinite group | Cross-ratio