Galois theory: Discriminants
Channel: Richard E Borcherds
Date: 2021-01-16

This lecture is part of an online graduate course on Galois theory.

We define the discriminant of a finite field extension, ans show that it is essentially the same as the discriminant of a minimal polynomial of a generator. We then give some applications to algebraic number fields.

Corrections: On the first sheet A^2 should be det(A)^2
On sheet 5  at 11:00 there are some sign errors on the bottom right: the polynomial should be b^3-b-1 with discriminant -23