Donald C. Spencer

Donald Spencer
Born	April 25, 1912(1912-04-25) Boulder, Colorado
Died	December 23, 2001(2001-12-23) (aged 89) Scottsdale, Arizona
Nationality	American
Institutions	Princeton University
Alma mater	University of Colorado MIT University of Cambridge
Doctoral advisor	J. E. Littlewood and G.H. Hardy
Doctoral students	Phillip Griffiths Joseph J. Kohn Patrick X. Gallagher
Notable awards	National Medal of Science

Donald Clayton Spencer (April 25, 1912 – December 23, 2001) was an American mathematician, known for major work on deformation theory of structures arising in differential geometry, and on several complex variables from the point of view of partial differential equations. He was born in Boulder, Colorado, and educated at the University of Colorado and MIT.

He wrote a Ph.D. in diophantine approximation under J. E. Littlewood at the University of Cambridge, completed in 1939. He had positions at MIT and Stanford before his appointment in 1950 at Princeton University. There he was involved in a major series of collaborative works with Kunihiko Kodaira on the deformation of complex structures, which had a profound influence on the theory of complex manifolds and algebraic geometry, and the conception of moduli spaces.

He also was led to formulate the d-bar Neumann problem, for the operator

$\bar{\partial}$

(see complex differential form) in PDE theory, to extend Hodge theory and the n-dimensional Cauchy-Riemann equations to the non-compact case. This is used to show existence theorems for holomorphic functions.

He later worked on pseudogroups and their deformation theory, based on a fresh approach to overdetermined systems of PDEs (bypassing the Cartan-Kähler ideas based on differential forms by making an intensive use of jets). Formulated at the level of various chain complexes, this gives rise to what is now called Spencer cohomology, a subtle and difficult theory both of formal and of analytical structure. This is a kind of Koszul complex theory, taken up by numerous mathematicians during the 1960s. In particular a theory for Lie equations formulated by Malgrange emerged, giving a very broad formulation of the notion of integrability.

After his death, a mountain peak outside of Silverton, Colorado was named in his honor.^[1]

See also

• Kodaira–Spencer mapping

References

1. ^ Pankratz, Howard (8/18/2008). "Spencer peak added to Colorado mountain lexicon". Denver Post. http://www.denverpost.com/headlines/ci_10237684. Retrieved 7/23/2011. 

External links

• Donald C. Spencer (1912-2001), Notices of the American Mathematical Society; vol. 51, no. 1 (January 2004).
• Donald C. Spencer at the Mathematics Genealogy Project.
• Donald C. Spencer, 89, Pioneering Mathematician, Dies, The New York Times; January 1, 2002.

Persondata
Name	Spencer, Donald C.
Alternative names
Short description
Date of birth	April 25, 1912
Place of birth	Boulder, Colorado
Date of death	December 23, 2001
Place of death	Scottsdale, Arizona