Below follows a collection of random notes that I have written in the course of learning various topics, or as preparation for some research project. They are made available here in case they are useful for students or others interested in similar stuff. These notes have not been proofread and are bound to contain numerous mistakes and inaccuracies. Use at your own risk.

Daniel Persson

Associate Professor

Division of Algebra and Geometry

Department of Mathematical Sciences

Chalmers University of Technology