Author Description

This collection of thirteen papers takes the reader on a journey through many important mathematical developments over the past half century. Among the authors and topics are: J. Milnor on curvature and fundamental group; M.F. Atiyah on equivariant K-theory; Gheorghe Lusztig on Novikov's higher signature and families of elliptic operators; and Edward Witten on super-symmetry and Morse theory.