{{short description|American mathematician}} {{for|the actor and comedian|Phil Hartman}} {{Infobox scientist | name = Philip Hartman | image = | alt = | caption = | birth_date = {{Birth date|df=yes|1915|5|16}} | birth_place = Baltimore<ref>James McKeen Cattell, ''American Men of Science'', 1966</ref> | death_date = {{Death date and age|df=yes|2015|8|28|1915|5|16}} | death_place = | fields = Mathematics | workplaces = Johns Hopkins University<br/> Queens College | alma_mater = Johns Hopkins University<ref>[https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/36753/commencement1938.pdf?sequence=1 Conferring of Degrees, The Johns Hopkins University, Baltimore, June 14 1938].</ref> | doctoral_advisor = Aurel Wintner<ref name=genealogy>{{MathGenealogy|id=11479}}</ref> | doctoral_students = Charles C. Pugh | awards = Guggenheim Fellowship (Mathematics, 1950),<ref name=guggenheim>[http://www.gf.org/fellows/all-fellows/philip-hartman/ Philip Hartman, John Simon Guggenheim Memorial Foundation].</ref> <br/> Honorary Member of the AMS<ref name=ams>[https://www.ams.org/notices/200011/from.pdf Honorary Members of the AMS]</ref> | known_for = Hartman–Grobman theorem, Hartman–Watson distribution }}

'''Philip Hartman''' (May 16, 1915 &ndash; 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.<ref>{{Cite web|url=https://oakland.edu/enp/compute/|title=Compute your Erdös number - The Erdös Number Project- Oakland University|website=oakland.edu|language=en|access-date=2017-08-15}}</ref>

His book gives a necessary and sufficient condition for solutions of ordinary initial value problems to be unique and to depend on a class C<sup>1</sup> manner on the initial conditions for solutions.

He died in August 2015 at the age of 100.<ref>{{Cite arXiv |eprint = 1510.03779|last1 = Newhouse|first1 = Sheldon E.|title = On a differentiable linearization theorem of Philip Hartman|class = math.DS|year = 2015}}</ref>

The Hartman–Watson distribution is named after him and Geoffrey S. Watson. == Publications == *{{Citation | last1=Hartman | first1=Philip | title=Ordinary differential equations | orig-date=1964 | url=https://books.google.com/books?id=CENAPMUEpfoC | publisher=Society for Industrial and Applied Mathematics | location=Philadelphia | series=Classics in Applied Mathematics | isbn=978-0-89871-510-1 |mr=1929104 | year=2002 | volume=38}}

== References == {{reflist}}

== External links == *{{MathGenealogy|id=11479}}

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{{DEFAULTSORT:Hartman, Philip}} Category:1915 births Category:2015 deaths Category:Educators from Baltimore Category:20th-century American mathematicians Category:American men centenarians Category:Johns Hopkins University alumni Category:Johns Hopkins University faculty Category:Dynamical systems theorists Category:American mathematical analysts