Category Theory

Math 35406


Winter 2006
TTh 1:30--2:50, Eck 207

Eugenia Cheng
Office: Eckhart 333


This is a first course in Category Theory, with no prerequisites. Examples will be taken from various areas of mathematics but these will be given as examples rather than as starting points, so prior knowledge of all examples is not necessary.  Everyone is welcome.


Material I intend to cover

Categories, functors and natural transformations. Examples drawn from different areas of mathematics.
Equivalence of categories, skeletons.
Representable functors, the Yoneda lemma.
Adjunctions.
Limits and colimits. Preservation and creation. 
Density, completion, fibrations.
The Adjoint Functor Theorems.
Kan extensions.
Monads.
The Eilenberg-Moore and Kleisli categories, and their universal properties.
Monadic adjunctions, Beck's Monadicity Theorem.
Enriched categories, internal categories, monoidal categories, bicategories, n-categories.

For a schedule of what I intend to cover in each class, click here.

References

1. F. Borceux, Handbook of Categorical Algebra, Cambridge U.P., 1994. Three volumes which together provide perhaps the best modern account of everything you should know about category theory: volume 1 covers most but not all of this course.

2. S. Mac Lane, Categories for the Working Mathematician, Springer-Verlag, second edition 1998. Still the best one-volume book on the subject, written by one of its founders.

Printed notes

This course will be a variant of the one I taught in Cambridge in 2001 and 2002.  Notes for that course were typed up by Richard Garner.  Please note that these were originally just for his own personal use.  

notes in pdf