About this Course
최근 조회 6,314

100% 온라인

지금 바로 시작해 나만의 일정에 따라 학습을 진행하세요.

탄력적인 마감일

일정에 따라 마감일을 재설정합니다.

고급 단계

완료하는 데 약 45시간 필요

권장: 9 weeks of study, 4-8 hours/week...

영어

자막: 영어

100% 온라인

지금 바로 시작해 나만의 일정에 따라 학습을 진행하세요.

탄력적인 마감일

일정에 따라 마감일을 재설정합니다.

고급 단계

완료하는 데 약 45시간 필요

권장: 9 weeks of study, 4-8 hours/week...

영어

자막: 영어

강의 계획 - 이 강좌에서 배울 내용

1
완료하는 데 23분 필요

Introduction

This is just a two-minutes advertisement and a short reference list....
1 video (Total 3 min), 2 readings
1개의 동영상
2개의 읽기 자료
Introduction/Manual10m
References10m
완료하는 데 2시간 필요

Week 1

We introduce the basic notions such as a field extension, algebraic element, minimal polynomial, finite extension, and study their very basic properties such as the multiplicativity of degree in towers....
6 videos (Total 84 min), 1 quiz
6개의 동영상
1.2 Algebraic elements. Minimal polynomial.12m
1.3 Algebraic elements. Algebraic extensions.14m
1.4 Finite extensions. Algebraicity and finiteness.14m
1.5 Algebraicity in towers. An example.14m
1.6. A digression: Gauss lemma, Eisenstein criterion.13m
1개 연습문제
Quiz 140m
2
완료하는 데 2시간 필요

Week 2

We introduce the notion of a stem field and a splitting field (of a polynomial). Using Zorn's lemma, we construct the algebraic closure of a field and deduce its unicity (up to an isomorphism) from the theorem on extension of homomorphisms....
5 videos (Total 67 min), 1 quiz
5개의 동영상
2.2 Splitting field.11m
2.3 An example. Algebraic closure.14m
2.4 Algebraic closure (continued).15m
2.5 Extension of homomorphisms. Uniqueness of algebraic closure.11m
1개 연습문제
QUIZ 240m
3
완료하는 데 4시간 필요

Week 3

We recall the construction and basic properties of finite fields. We prove that the multiplicative group of a finite field is cyclic, and that the automorphism group of a finite field is cyclic generated by the Frobenius map. We introduce the notions of separable (resp. purely inseparable) elements, extensions, degree. We briefly discuss perfect fields. This week, the first ungraded assignment (in order to practice the subject a little bit) is given. ...
6 videos (Total 82 min), 1 reading, 1 quiz
6개의 동영상
3.2 Properties of finite fields.14m
3.3 Multiplicative group and automorphism group of a finite field.15m
3.4 Separable elements.15m
3.5. Separable degree, separable extensions.15m
3.6 Perfect fields.9m
1개의 읽기 자료
Ungraded assignment 1
1개 연습문제
QUIZ 340m
4
완료하는 데 2시간 필요

Week 4

This is a digression on commutative algebra. We introduce and study the notion of tensor product of modules over a ring. We prove a structure theorem for finite algebras over a field (a version of the well-known "Chinese remainder theorem")....
6 videos (Total 91 min), 1 quiz
6개의 동영상
4.2 Tensor product of modules14m
4.3 Base change14m
4.4 Examples. Tensor product of algebras.15m
4.5 Relatively prime ideals. Chinese remainder theorem.14m
4.6 Structure of finite algebras over a field. Examples.16m
1개 연습문제
QUIZ 440m
5
완료하는 데 4시간 필요

Week 5

We apply the discussion from the last lecture to the case of field extensions. We show that the separable extensions remain reduced after a base change: the inseparability is responsible for eventual nilpotents. As our next subject, we introduce normal and Galois extensions and prove Artin's theorem on invariants. This week, the first graded assignment is given....
6 videos (Total 81 min), 2 quizzes
6개의 동영상
5.2 Separability and base change14m
5.3 Separability and base change (cont'd). Primitive element theorem.14m
5.4 Examples. Normal extensions.13m
5.5 Galois extensions.11m
5.6 Artin's theorem.13m
1개 연습문제
QUIZ 540m
6
완료하는 데 2시간 필요

Week 6

We state and prove the main theorem of these lectures: the Galois correspondence. Then we start doing examples (low degree, discriminant, finite fields, roots of unity)....
6 videos (Total 86 min), 1 quiz
6개의 동영상
6.2 The Galois correspondence14m
6.3 Galois correspondence (cont'd). First examples (polynomials of degree 2 and 3.14m
6.4 Discriminant. Degree 3 (cont'd). Finite fields.15m
6.5 An infinite degree example. Roots of unity: cyclotomic polynomials14m
6.6 Irreducibility of cyclotomic polynomial.The Galois group.14m
1개 연습문제
QUIZ 640m
7
완료하는 데 4시간 필요

Week 7

We continue to study the examples: cyclotomic extensions (roots of unity), cyclic extensions (Kummer and Artin-Schreier extensions). We introduce the notion of the composite extension and make remarks on its Galois group (when it is Galois), in the case when the composed extensions are in some sense independent and one or both of them is Galois. The notion of independence is also given a precise sense ("linearly disjoint extensions"). This week, an ungraded assignment is given....
7 videos (Total 87 min), 1 reading
7개의 동영상
7.2. Kummer extensions.14m
7.3. Artin-Schreier extensions.11m
7.4. Composite extensions. Properties.13m
7.5. Linearly disjoint extensions. Examples.15m
7.6. Linearly disjoint extensions in the Galois case.12m
7.7 On the Galois group of the composite.7m
1개의 읽기 자료
Ungraded assignment 25m
8
완료하는 데 2시간 필요

Week 8

We finally arrive to the source of Galois theory, the question which motivated Galois himself: which equation are solvable by radicals and which are not? We explain Galois' result: an equation is solvable by radicals if and only if its Galois group is solvable in the sense of group theory. In particular we see that the "general" equation of degree at least 5 is not solvable by radicals. We briefly discuss the relations to representation theory and to topological coverings....
6 videos (Total 81 min), 1 quiz
6개의 동영상
8.2. Properties of solvable groups. Symmetric group.13m
8.3.Galois theorem on solvability by radicals.11m
8.4.Examples of equations not solvable by radicals."General equation".13m
8.5. Galois action as a representation. Normal base theorem.14m
8.6. Normal base theorem (cont'd). Relation with coverings.12m
1개 연습문제
QUIZ 840m
9
완료하는 데 4시간 필요

Week 9.

We build a tool for finding elements in Galois groups, learning to use the reduction modulo p. For this, we have to talk a little bit about integral ring extensions and also about norms and traces.This week, the final graded assignment is given....
6 videos (Total 84 min), 2 quizzes
6개의 동영상
9.2. Integral extensions, integral closure, ring of integers of a number field.15m
9.3. Norm and trace.14m
9.4. Norm and trace (cont'd). Ring of integers is a free module.13m
9.5. Reduction modulo a prime.13m
9.6. Reduction modulo a prime and finding elements in Galois groups.14m
1개 연습문제
QUIZ 940m
4.3
27개의 리뷰Chevron Right

최상위 리뷰

대학: CLJun 16th 2016

Outstanding course so far - a great refresher for me on Galois theory. It's nice to see more advanced mathematics classes on Coursera.

강사

Avatar

Ekaterina Amerik

Professor
Department of Mathematics

국립 연구 고등 경제 대학 정보

National Research University - Higher School of Economics (HSE) is one of the top research universities in Russia. Established in 1992 to promote new research and teaching in economics and related disciplines, it now offers programs at all levels of university education across an extraordinary range of fields of study including business, sociology, cultural studies, philosophy, political science, international relations, law, Asian studies, media and communicamathematics, engineering, and more. Learn more on www.hse.ru...

자주 묻는 질문

  • 강좌에 등록하면 바로 모든 비디오, 테스트 및 프로그래밍 과제(해당하는 경우)에 접근할 수 있습니다. 상호 첨삭 과제는 이 세션이 시작된 경우에만 제출하고 검토할 수 있습니다. 강좌를 구매하지 않고 살펴보기만 하면 특정 과제에 접근하지 못할 수 있습니다.

  • 수료증을 구매하면 성적 평가 과제를 포함한 모든 강좌 자료에 접근할 수 있습니다. 강좌를 완료하면 전자 수료증이 성취도 페이지에 추가되며, 해당 페이지에서 수료증을 인쇄하거나 LinkedIn 프로필에 수료증을 추가할 수 있습니다. 강좌 콘텐츠만 읽고 살펴보려면 해당 강좌를 무료로 청강할 수 있습니다.

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