# Math 845 - Spring 2011

# Nigel Boston

## Contact Information

303 Van Vleck Hall.
Telephone: 263-4753.

E-mail: *boston@math.wisc.edu*

Homepage

Office Hours: T 1-2:30 in 303 VV or R 10:45-12:15 in 303 VV, or by appointment.

## Text

There is no perfect text for class field theory. The best resources for teaching it are, I think,
Milne's notes
and Neukirch's book ``Algebraic Number Theory". I was planning on combining these, but then realized
that Kedlaya's notes do this already.
I will therefore be mostly following his notes - check them out!
## Course Overview

Class field theory is the description of extensions of a number field (or local field) K in terms of the arithmetic of K.
For extensions with abelian Galois group, the theory was the focal point of algebraic number theory from about 1850 to 1930. The nonabelian
case has many conjectures and increasingly many proofs (in fact the last decade or so has seen exciting advances).
In this course abelian class field theory will be completely covered, requiring the introduction
of many of the tools in the armory of the modern number theorist, such as Galois cohomology, L-series, etc. Applications of historical
and modern importance will be presented en route together with several concrete examples. Check out the course notes to learn more.
There is a lovely recent article by Barry
Mazur on constructing abelian extensions of number fields that continues from around about where this course will end.
## Sections

- Main Lecture: TR 9:30-10:45 B129 VV.

## Homework Assignments

- 1st Homework, pdf version
- 1st Homework, ps version
- 2nd Homework, pdf version
- 2nd Homework, ps version
- 3rd Homework, pdf version
- 3rd Homework, ps version
- 4th Homework, pdf version
- 4th Homework, ps version
- 5th Homework, pdf version
- 5th Homework, ps version

## Some Lists of Unsolved Problems

## General Information (e.g. Conferences)

## Online Notes

## Books on Class Field Theory

## History of Class Field Theory