Differential algebraic groups

The lectures will attempt to describe the general theory of differential algebraic groups that has been developed in recent years in analogy with and as a generalization of the older theory of algebraic 0rou9s. Limitations of time "make it necessary to omit a number of topics and to give broad descriptions instead of proofs. I have qiven Professor Tuan at least one copy of each of several references, and I hope that these can be consulted by anyone interested in any of the details. The main reference is the manuscript of my forth­coming book [8]; two earlier works that may prove helpful on occasion are my 1973 book [6] and my paoer [7]. Also included are reprints of five papers by P.J. Cassidy [1­5], one paper by J. Kovacic [9], and one paper by W.Y. Sit [10], all bearing on results in the theory that I shall not have time to describe. These lectures are intended as a selective survey of the subject.