Philip Hartman

For the actor and comedian, see Phil Hartman.

Philip Hartman (May 16, 1915 – August 28, 2015) was an American mathematician at Johns Hopkins University working on differential equations who introduced the Hartman–Grobman theorem. He served as Chairman of the Mathematics Department at Johns Hopkins for several years. He has an Erdös number of 2.^[6]

Philip Hartman
Born	(1915-05-16)16 May 1915 Baltimore[1]
Died	28 August 2015(2015-08-28) (aged 100)
Nationality	American
Alma mater	Johns Hopkins University[2]
Known for	Hartman–Grobman theorem, Hartman–Watson distribution
Awards	Guggenheim Fellowship (Mathematics, 1950),[3] Honorary Member of the AMS[4]
Scientific career
Fields	Mathematics
Institutions	Johns Hopkins University Queens College
Doctoral advisor	Aurel Wintner[5]
Doctoral students	Charles C. Pugh

His book gives a necessary and sufficient condition for solutions of ordinary initial value problems to be unique and to depend on a class C¹ manner on the initial conditions for solutions.

He died in August 2015 at the age of 100.^[7]

The Hartman–Watson distribution is named after him and Geoffrey S. Watson.

Publications

• Hartman, Philip (2002) [1964], Ordinary differential equations, Classics in Applied Mathematics, vol. 38, Philadelphia: Society for Industrial and Applied Mathematics, ISBN 978-0-89871-510-1, MR 1929104