This is Vol.2 of the Course of Theoretical Physics. It also covers General
Relativity. Like most volumes in this series, it’s an excellent book but not easy
to read.
A pdf version is available here .
This book is not required , and the course will
not follow it (or any other text) closely.
It's an excellent reference that you'll be likely
to use for as long as you stay in physics. However, if you like a different
book better, choose that.