13. MTH410 (Fall 2020) (Galois theory)

This is an undergraduate course on Galois theory.

There will be tutorials every Thursday (4-4.55).


No internal assessment only end-sem exam (100%).


Timing

Tuesday 2-3 pm (Recorded).

Wednesday 9-10 am (Recorded)

Thursday 4-5 pm (Live-Tutorial)


Text Book

Galois Theory (Joseph Rotman), second edition.

Dummit and Foote


Week 1

01/09/2020: Introduction to the course.

02/09/2020:Motivation for studying Galois theory. Review

from group theory.

03/09/2020:Polynomial rings: Irreducible polynomials, Euclid's algorithms, gcd and lcm of polynomials.



Week 2

08/09/2020:Fields, Prime subfields, different criteria for irreducibility

criteria like Eisenstein, prime subfields.

09/09/2020:Algebraic elements and algebraic extensions.

10/09/2020: Tutorial (Live)


Week 3

15/09/2020:Simple extensions: primitive element theorem.

16/09/2020:Finite fields, Frobenius elements.

17/09/2020: Tutorial (Live): Syllabus-upto ``Algebraic elements and algebraic extensions". Question paper will be sent by email. You may wish to return the answer sheet if you wish (not compulsary).

Week 4

22/9/20: Frobenius automorphism

23/9/20:Splitting fields

24/9/20:Tutorial


Week 5

29/09/2020:Normal extensions (definition).

30/09/2020: Algebraic closure: "Existence and uniqueness of algebraic closure.

01/10/20: Quiz 2


Week 6

October 6:Separable extensions."Normal+separable=Galois.

October 7:Automorphisms and Galois groups.

October8:Tutorial

Week7


October 13:Revision

October 14: Revision

October 15:Short test,


Week 8

October 20:Computations of the Galois groups, Dedekind's Lemma.

October 21:Solvable groups and radical extensions, Galois group of cyclotomic fields.

October 22: Tutorial

Week 9

Teaching break


Week 10

November 3: Fixed fields and subgroups of Galois groups.

November 4: Fundamental theorem of Galois theory.

Week 11

November 10: Some applications of Fundamental theorem of Galois theory:

November 11 :Galois group of composite fields and intersections.

Week 12:

November 17 :Cyclic extensions,

November 18:Fundamental theorem in the context of cyclotomic extension

Week 13

November 24:Norms and traces, Hilbert's Theorem 90.

November 25: Polynomial being solvable by radicals if and only if the Galois group of the splitting field is solvable.

Week 14.

December 1: Detecting when Galois groups are symmetric and Alternating subgroups, resolvent cubic.

December 2:Transitive subgroups of symmetric groups.

Week 15.

December 8:Ruler and compass constructions

December 9: Constructibility of regular n-gon. Assignment 9 uploaded.


Week 16

December 15:Fundamental theorem of Galois theory

in the context of Cyclotomic extensions.


December 16: Abelian extensions of rationals.

Week 17

December 22: Artin-Schreier extensions

December 23: Revision on "ruler and compass construction".