FALL 2019               Math 461 --- RINGS AND MODULES

Prerequisite: Math 367 or consent of instructor.       Credits: (3-0) 3.   

Instructor:  Semra Öztürk, M 138,     Schedule  and office hours are at the address   http:/www.metu.edu.tr/~sozkap/aa.pdf.

Catalog Contents: Rings, ideals, isomorphism theorems, group rings, localization, factor rings. Modules, submodules, direct products, factor modules. Homomorphisms, classical isomorphism theorems. The endomorphism ring of a module. Free modules, free groups. Tensor product of modules. Finitely generated modules over a principal ideal domain.  

Grading will be based on two midterms %40 each, one  final exam %50, and attendence/class participation %10.

You should take both of the midterm exams, I will omit the lower grade (even if you are happy with your first midterm grade you still have to take the second midterm exam)

 

Attendence is required, attendance and class participation will be %10 of the course grade.

 

Description  of the course: This course is to provide  the background for students who are willing to learn more about rings which are  the fundamental mathematical structures occuring everywhere !  It is good for everyone J but especially for students who are planning to study  any  algebra related topics such as algebraic topology, algebraic geometry, even analysis .  As the title suggests this course consists of two parts, rings and modules. 

This semester I will spend less than the first half of the semester on rings and spend more time on modules.   We will skip  tensor products completely.   Rings will be  a more detailed but faster version of some of the topics  you have seen in Math 367, and  Math 116.   Modules will be new to you. They are generalizations of  vector spaces also generalization of abelian groups.  Thus in  module theory  linear algebra comes up  quite often.  You should be comfortable using linear algebra to get more out of this course. We will see the primary decomposition theorem for  finitely generated modules over a Euclidean domain.

 

Modules over group algebras are examples of groups acting on vector spaces.

About 5-6 weeks we will cover Rings : rings, subrings,  ideals, quotient rings, annihilators, homorphism of rings, isomorphism theorem for rings, rings of fractions, Chineese remainder theorem, Euclidean domains, principal ideal domains,   group algebras, polynomial rings.

About 7-8 weeks we will cover  Modules: modules , submodules, simple modules, Schur’s Lemma, generation of modules, direct sums,  annilators of modules, free modules, torsion modules, torsion-free modules,  finitely generated torsin free modules, modules over a Euclidean domain or  over a principal ideal domain, primary decomposition theorem, elementary divisors, invariant factors, (the rational canonical form , if there is enough time and interest). You can print a tentative syllabus from here.

 

I  will use  two textbooks this semester :

1) Abstract Algebra by  David S. Dummit and Richard M. Foote, Third Edition,  only the   Preliminaries and  Chapter 7 .

2) A First Course in Module Theory by M. E. Keating, Imperial Clollege Press,  only the Chapters 2--9 

Another book that I  used for this course  in previous semesters (you may find it useful as well) : Introduction to Rings and Modules, Second Revised Edition, by C. Musili, Narosa Publishing House, 1994,   only  Chapters 1--5 ( the part for rings is too long and the part for modules is too short) 

 

 A nice set of lecture notes by Mike Prest which covers more topics  than our course content advanced students may like it,.(Chapters 0,1,2,6 are usefull for this course,  at first reading omit Chapters 3, 4,  5)

 Supplementary solved exercises  

 The number of homomorphisms from Zn to Zm.pdf 

 Classification_of_Finite-Finite rings.pdf