Absolute Galois group

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

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

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

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

Galois theory: Algebraic closure

This lecture is part of an online graduate course on Galois theory. We define the algebraic closure of a field as a sort of splitting field of all polynomials, and check that it is algebraically closed. We hen give a topological proof that the field C of complex numbers is algebraically

From playlist Galois theory

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

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

FIT4.2. Automorphisms and Degree

EDIT: As noted before, my source (Herstein) assumes characteristic 0 for the initial Galois theory section. We'll assume separability unless noted. Note that Galois = separable plus normal. Field Theory: Having established an estimate on the size of a Galois group of a polynomial, w

From playlist Abstract Algebra

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

FIT4.3.1. Galois Group of Order 8

Field Theory: Let K be Q[sqrt(2), sqrt(3), sqrt(5)], the splitting field of f(x) = (x^2-2)(x^2-3)(x^2-5) over Q. Find the Galois group of K over Q, find all subgroups of the Galois group, and find all subfields of K over Q.

From playlist Abstract Algebra

Barry Mazur - Logic, Elliptic curves, and Diophantine stability

This is the third lecture of the 2014 Minerva Lecture series at the Princeton University Mathematics Department. October 17, 2014 An introduction to aspects of mathematical logic and the arithmetic of elliptic curves that make these branches of mathematics inspiring to each other. Speci

From playlist Minerva Lectures - Barry Mazur

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)

Perfectoid spaces (Lecture 1) by Kiran Kedlaya

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) Eknath

From playlist Perfectoid Spaces 2019

Peter Scholze - Locally symmetric spaces, and Galois representations (1)

Lecture: Locally symmetric spaces, and Galois representations Speaker: Peter Scholze (The University of Bonn, Germany) Date: 25 Mar 2014, 11:30 AM Venue: AG 66, TIFR, Mumbai One of the most studied objects in mathematics is the modular curve, given as the locally symmetric space whic

From playlist Locally symmetric spaces, and Galois representations

Filip Najman, Q-curves over odd degree fields and sporadic points

VaNTAGe seminar June 29, 2021 License: CC-BY-NC-SA

From playlist Modular curves and Galois representations

Francesc Fité, Sato-Tate groups of abelian varieties of dimension up to 3

VaNTAGe seminar on April 7, 2020 License: CC-BY-NC-SA Closed captions provided by Jun Bo Lau.

From playlist The Sato-Tate conjecture for abelian varieties

Kevin Buzzard (lecture 3/20) 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]

CTNT 2020 - Computations in Number Theory (by Alvaro Lozano-Robledo) - Lecture 1

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 - Computations in Number Theory Research

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