Math 513C: Noncommutative and Noetherian Rings

Paul Smith

Spring 1999, MWF 3:30-4:20

Course Organization

One of the fundamental questions motivating the study of noncommutative algebras is the problem of classifying/understanding the solutions to equations in matrices. For example, finding matrices x,y,z satisfying xy-yx=z, yz-zy=x, zx-xz=y is equivalent to the problem of understanding the finite dimensional representations of the Lie algebra so(3). Associated to such a system of equations is a noncommutative ring (for this example the ring is the enveloping algebra of so(3)). The structure of this ring yields information about the solutions to the system. If one only wants solutions in 1x1 matrices, or equivalently, if one only wants solutions in the base field over which one is working, then one can take the ring to be commutative, and then the solutions are in bijection with the points on the algebraic variety corresponding to the ring. This is the starting point of algebraic geometry.

In the past decade there has been an effort to obtain a similar geometric point of view when one seeks solutions in n x n matrices (for all n). This two-quarter course (beginning Spring 1999, continuing in Fall 1999) will examine some of these developments which go under the general heading of ``noncommutative algebraic geometry.'' I will focus particularly on noncommutative (projective) surfaces. The classification of commutative algebraic surfaces is one of the high points of classical algebraic geometry (the work of Castelnuovo, Enriques, Severi, et alia, between 1895 and 1910). We will review the relevant parts of that and examine noncommutative surfaces from a similar viewpoint.

A large part of the course will be devoted to the theory of noncommutative Noetherian rings; these algebraic preliminaries provide the infrastructure needed for the geometric part of the course. Among the basic examples we will study are the enveloping algebras of finite dimensional Lie algebras, and rings of differential operators on curves.

Course Organization

I will construct a Web site for the course, and a chat room. All the course materials, lectures, reading assignments, homework etc., will be posted on the Web. I will advertise the course at other universities where there are people studying noncommutative rings and noncommutative algebraic geometry. I hope that the course will be followed by a variety of people from various places. I hope that the chat room will provide a forum for students here and elsewhere to discuss the course, ask questions, get their questions answered et cetera. The URL is
http://www.math.washington.edu/~smith/Teaching/513nag/nag99.html.