Donald C. Spencer

Donald Clayton Spencer (1912-2001) was an American mathematician known for his work on the deformation theory of structures arising in differential geometry and on several complex variables seen through partial differential equations. Born in Boulder, Colorado, he was educated at the University of Colorado and MIT and wrote a Cambridge doctorate in diophantine approximation, completed in 1939 under J. E. Littlewood and G. H. Hardy. After positions at MIT and Stanford he joined Princeton University in 1950, where he collaborated with Kunihiko Kodaira on the deformation of complex structures, work that influenced the theory of complex manifolds, algebraic geometry and moduli spaces. He formulated the d-bar Neumann problem and later worked on pseudogroups, giving rise to what is now called Spencer cohomology. A mountain peak near Silverton, Colorado was named in his honor.