Stefan E. Warschawski

{{Infobox scientist

|name = Stefan Warschawski

|birth_date = {{birth date|1904|04|18|df=y}}

|death_date = {{death date and age|1989|05|05|1904|04|18|df=y}}

|alma_mater = University of Göttingen
University of Königsberg

|workplaces = University of California, San Diego
Washington University in St. Louis
Brown University
University of Minnesota|

|doctoral_advisor = Alexander Ostrowski

|doctoral_students = Vernor Vinge

}}

Stefan Emanuel "Steve" Warschawski (April 18, 1904 – May 5, 1989) was a Russian-born American mathematician, a professor and department chair at the University of Minnesota and the founder of the mathematics department at the University of California, San Diego.

Early life and education

Warschawski was born in Lida, now in Belarus; at the time of his birth Lida was part of the Russian Empire.{{MacTutor|id=Warschawski|title=Stefan E Warschawski}}.{{citation|first=F. David|last=Lesley|title=Biography of S. E. Warschawski|journal=Complex Variables, Theory and Application|volume=5|issue=2–4|year=1986|pages=95–109|doi=10.1080/17476938608814131}}.{{citation|first1=Carl H.|last1=FitzGerald|first2=Burton|last2=Rodin|authorlink2=Burton Rodin|first3=Helmut|last3=Röhrl|authorlink3=Helmut Röhrl|contribution=Stefan E. Warschawski, Mathematics: San Diego|url=http://content.cdlib.org/view?docId=hb4p30063r&doc.view=content&chunk.id=div00071&toc.depth=1&brand=calisphere&anchor.id=0|title=University of California: In Memoriam, 1989|publisher=University of California Academic Senate|year=1989|pages=199–201}}. His father was a Russian medical doctor, and his mother was ethnically German;{{citation|title=Founded Mathematics Department at UCSD Prof. Stefan E. Warschawski Dies at 85|journal=Los Angeles Times|date=May 10, 1989|first=Maureen|last=Fan}}. the family spoke German at home. In 1915, his family moved to Königsberg, in Prussia (now Kaliningrad, Russia), the home of his mother's family.

Warschawski studied at the University of Königsberg until 1926 and then moved to the University of Göttingen for his doctoral studies under the supervision of Alexander Ostrowski. Ostrowski moved to the University of Basel and Warschawski followed him there to complete his studies.

Career

After receiving his Ph.D., Warschawski took a position at Göttingen in 1930 but, due to the rise of Hitler and his own Jewish ancestry, he soon moved to Utrecht University in Utrecht, Netherlands and then Columbia University in New York City.

After a sequence of temporary positions, he found a permanent faculty position at Washington University in St. Louis in 1939. During World War II he moved to Brown University and then the University of Minnesota, where he remained until his 1963 move to San Diego, where he was the founding chair of the mathematics department.{{citation|url=http://math.ucsd.edu/~chair/facultyhistory.html|title=UCSD Mathematics: Faculty History|publisher=UCSD Mathematics Department|accessdate=2009-09-07}}.{{citation|url=http://math.ucsd.edu/programs/undergraduate/scholarship_winners/bishop_warsch_99_00.php|title=The Stephen E. Warschawski Memorial Scholarship|publisher=UCSD Mathematics Department|accessdate=2009-09-07}}. Warschawski stepped down as chair in 1967, and retired in 1971, but remained active in research: approximately one third of his research publications were written after his retirement. Over the course of his career, he advised 19 Ph.D. students, all but one at either Minnesota or San Diego.{{MathGenealogy|id=43227|name=Stefan Warschawski}} Vernor Vinge is among Warschawski's doctoral students.

Research

Warschawski was known for his research on complex analysis and in particular on conformal maps. He also made contributions to the theory of minimal surfaces and harmonic functions.

The Noshiro–Warschawski theorem is named after Warschawski and Noshiro, who discovered it independently;{{citation|first=K.|last=Noshiro|title=On the theory of Schlicht functions|journal=J. Fac. Sci. Hokkaido Imperial Univ.|volume=2|pages=129–155|year=1934–1935|issue=3|doi=10.14492/hokmj/1531209828|doi-access=free|hdl=2115/55907|hdl-access=free}}.{{citation|first=S.|last=Warschawski|year=1935|title=On the higher derivatives at the boundary in conformal mapping|journal=Transactions of the American Mathematical Society|volume=38|pages=310–340|doi=10.2307/1989685|jstor=1989685|issue=2|publisher=American Mathematical Society|doi-access=free}}.{{citation|title=Quasidisks and the Noshiro-Warschawski criterion|first1=Martin|last1=Chuaqui|first2=Julian|last2=Gevirtz|journal=Complex Variables and Elliptic Equations|volume=48|issue=11|year=2003|pages=967–985|doi=10.1080/02781070310001617637|s2cid=124760496}}.{{citation|first=A. W.|last=Goodman|title=A note on the Noshiro-Warschawski theorem|journal=Journal d'Analyse Mathématique|volume=25|issue=1|year=1972|pages=401–408|doi=10.1007/BF02790048|doi-access=free|s2cid=120826315}}. it states that, if f is an analytic function on the open unit disk such that the real part of its first derivative is positive, then f is one-to-one.

In 1980, he solved the Visser–Ostrowski problem for derivatives of conformal mappings at the boundary.Burton Rodin and S. E. Warschawski, “On the derivative of the Riemann mapping function near a boundary point and the Visser-Ostrowski problem”, Mathematische Annalen, 248, (1980), 125–137.

Legacy

Warschawski was honored in 1978 by the creation of the Stefan E. Warschawski Assistant Professorship at San Diego. The Stephen E. Warschawski Memorial Scholarship was also given in his name in 1999–2000 to four UCSD undergraduates as a one-time award. His wife, Ilse, died in 2009 and left a US$1 million bequest to UCSD, part of which went towards endowing a professorship in the mathematics department.{{citation|title=Ilse Warschawski Trust Gives $1 Million to Help UC San Diego Recruit Outstanding Scholars|url=http://ucsdnews.ucsd.edu/newsrel/campaign/05-09Warschawski.asp|date=May 13, 2009|first=Jade|last=Griffin|publisher=UC San Diego News Center}}.