MATHEMATICS W4043, Fall 2017

Algebraic Number Theory



Time:  10:10-11:25, Monday and Wednesday

Instructor:  Michael Harris

Office Hours:  Monday and Wednesday, 11:30-12:30 and by appointment, room number 521


Teaching Assistant: Samuel Mundy





This is an introduction to the algebraic theory of numbers.   The fundamental

techniques of the subject will be accompanied by the study of examples

of families of Diophantine equations that motivated the development of the subject.


Each of the topics listed below will occupy roughly two weeks of course time:


1.  Algebraic integers, factorization, Dedekind rings, local rings

            (Gauss's first proof of quadratic reciprocity)

2.  Units and class groups (Pell's equation, classification of binary quadratic forms)

3.  Cyclotomic fields (Fermat's last theorem for regular primes, first case;

            Gauss's fourth proof of quadratic reciprocity)

4.  Congruences and p-adic numbers (the Chevalley-Warning theorem)

5.  Zeta and L-functions (Dirichlet's theorem on primes in an arithmetic progression)

6.  Other topics (depending on class interest:  Dirichlet's unit theorem, the prime number theorem,

            cubic equations…)


Prerequisites:  Basic algebra through Galois theory.  Some elements of complex

            analysis may be admitted in section 5.



Textbook:  Marc Hindry, Arithmetics (Springer, 2011 edition)

Other useful references include


            Dan Flath, Introduction to Number Theory

            Pierre Samuel, Algebraic Theory of Numbers

            Jean-Pierre Serre, A Course in Arithmetic


The grade will be based on homework (20%), the midterm (30%), and the take-home final (50%).   


Midterm:  October 25

Final:  FINAL EXAM (online December 11, due December 18)



            Homework assignments

1st week  (due September 13)      

2nd week (due September 20)      

3rd week (due September 27)       

4th week (due October 4)

5th week (due October 11)

6th week (due October 18)

             (Midterm:  no homework)

7th week (due November 1)

8th week (due November 8)

9th week (due November 15 )

10th week (due November 29)

11th week (due December 6)



The final from the fall of 2013 is available here.

The final from the fall of 2015 is available here.


Course notes





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