Number Theory I Autumn 2022

Lecturer
Sarah Zerbes
Coordinator
Wooyeon Kim | wooyeon.kim@math.ethz.ch
Lectures
Tuesdays 10:15-12:00, HG D 1.2
Fridays 10:15-12:00, HG D 7.1
Exercise classes will be held on every Fridays (from the second week) 10:15-11:00, before the lecture.

Content

This course will give an introduction to the theory of number fields, which are fundamental objects in algebraic number theory. We will cover the following topics:

- review of field extensions, algebraic numbers

- rings of integers, discriminants, integral bases

- examples: cyclotomic fields

- non-unique factorisation of algebraic integers, unique factorisation into prime ideals

- fractional ideals, class groups

- lattices and Minkowski's lemma, finiteness of the class group

- computations of the class number

- group of units of a number field

- Dedekind zeta functions, class number formula

Prerequisites

Gaolis theory

Lecture Notes

Dates Notes
September 20 Lecture 1
September 23 Lecture 2
September 27 Lecture 3
September 30 Lecture 4
October 4 Lecture 5
October 7 Lecture 6
October 11 Lecture 7
October 14 Lecture 8
October 18 Lecture 9
October 21 Lecture 10
October 25 Lecture 11
October 28 Lecture 12
November 1 Lecture 13
November 4 Lecture 14
November 11 Lecture 15
November 15 Lecture 16
November 18 Lecture 17
November 22 Lecture 18
November 25 Lecture 19
November 29 Lecture 20
December 2 Lecture 21
December 6 Lecture 22
December 9 Lecture 23
December 13 Lecture 24
December 17 Lecture 25

Exercises

Dates Exercise sheets Solutions
September 30 Problems 1 Solutions 1
October 14 Problems 2 Solutions 2
October 21 Problems 3 Solutions 3
October 28 Problems 4 Solutions 4
November 4 Problems 5 Solutions 5
November 11 Problems 6 Solutions 6
November 25 Problems 7 Solutions 7
December 2 Problems 8 Solutions 8
December 9 Problems 9 Solutions 9
December 16 Problems 10 Solutions 10

Literature