Stefan E Warschawski
Born: 18 April 1904 in Lida, Russia (now Belarus)
Died: 5 May 1989 in San Diego, California, USA

Stefan Warschawski was born in Lida, a city which alternated between
being in Poland or Russia. At the time that Warschawski was born, Lida
was part of Russia but reverted to Poland in 1919. Despite the fact
that the city was controlled by either Russia or Poland, the
Warschawski household were German speaking. However, when the German
armies attacked Lida in 1915 during World War I, his family left the
city and went to live in Königsberg where mother's parents lived. It
was in Königsberg that he attended the gymnasium, graduating in 1924.

After completing his studies at the gymnasium, Warschawski entered the
University of Königsberg. There he was taught by Knopp and Rogosinski.
After two years of study he moved to Göttingen to study for his
doctorate. Although the university was staffed by leading
mathematicians like Landau, Courant, and Herglotz, whose courses he
took, it was Alexander Ostrowski, at that time a privatdozent, who
supervised Warschawski's research. Ostrowski had taken up the position
in Göttingen in 1923 but when Warschawski began his studies in 1926 he
had just returned from a year of study in Britain at the universities
of Oxford, Cambridge and Edinburgh. He had not been supervising
Warschawski for long when he was offered the chair of mathematics at
the University of Basel. Warschawski moved to Basel with his
supervisor and there completed working on his thesis on the boundary
behaviour of conformal mappings.

After the award of his doctorate Warschawski was offered a position
back at Göttingen and he returned there to start teaching courses in
session 1930-31. On 30 January 1933 Hitler came to power and on 1
April there was the so-called "boycott day" when Jewish shops were
boycotted and Jewish lecturers were not allowed to enter their
university. On 7 April 1933 the Civil Service Law provided the means
of removing Jewish teachers from the universities, and of course also
to remove those of Jewish descent from other roles. All civil servants
who were not of Aryan descent (having one grandparent of the Jewish
religion made someone non-Aryan) were to be retired. Warschawski
realised that he could not make a career in Germany and he was helped
by Julius Wolff to obtain a one year post at the University of Utrecht
in Holland. At the end of that time, again with Wolff's help, he
obtained a one year position at Columbia University in New York.
Warschawski was immensely grateful to Wolff for helping him to escape
from the Nazis, but Wolff himself suffered the fate he helped others
avoid for he died during the Nazi occupation of the Netherlands.

In the United States at this time it was not easy to obtain permanent
posts. Many top class mathematicians had fled to the united States
from the Nazi threat in Europe and there were not enough positions
available. Warschawski published a major 30 page paper On the higher
derivatives at the boundary in conformal mapping in the Transactions
of the American Mathematical Society in 1935 but had to move from one
short term post to the next until he was offered a permanent position
in 1939 at Washington University in St Louis. A colleague interested
him in the method of computing mappings by successive approximation
and he soon was able to prove the necessary convergence theorems to
put the method on a firm theoretical basis. He published The
convergence of expansions resulting from a self-adjoint boundary
problem in the Duke Mathematical Journal in 1940, jointly with A S
Galbraith, which studied a problem of the Riesz-Fischer type
concerning the expansion of a function with n derivatives in terms of
the characteristic solutions of a self-adjoint boundary value problem
of the second order.

Carl H FitzGerald, Burton Rodin, and Helmut Rohrl have written an
obituary of Warschawski in which they say how he helped with the war
effort:-

In connection with the war effort, he taught extra courses; during one
semester, he lectured 36 hours a week. (Steve objected to the mention
of that load in an earlier biography. He was concerned that it might
be thought that he had complained about the load. As he saw it, other
people had it worse; he did not complain.)

Before World War II ended he joined the Applied Mathematics Group at
Brown University. Loewner also joined the group in 1944 to study
problems with military applications. Bergman, also forced to leave
Nazi Germany, was on the faculty at Brown when Warschawski joined, as
was Bers who was also undertaking research relevant to the war effort.
After a year at Brown, Warschawski moved to the University of
Minnesota and in March 1947 he married Ilse Kayser. He continued to
undertake research on conformal mapping publishing On conformal
mapping of regions bounded by smooth curves in 1951. In 1955 he
published two papers in Experiments in the computation of conformal
maps published in the National Bureau of Standards Applied Mathematics
Series. The first was a single author paper On the solution of the
Lichtenstein-Gershgorin integral equation in conformal mapping. I.
Theory while the second, On the solution of the
Lichtenstein-Gershgorin integral equation in conformal mapping. II.
Computational experiments, was written jointly with Jack Todd. The
computational results of iterating obtained in the second paper were
in good agreement with the theoretical results given in the first.

Warschawski was appointed chairman of the Mathematics Department in
the Institute of Technology at the University of Minnesota in 1952 and
was highly successful in building the Department over the following
eleven years. In 1963 he moved to the La Jolla campus of the
University of California San Diego. He was chairman of the Department
of Mathematics from 1963 until 1967 when ill health forced him to give
up the Chairmanship. He retired in 1971 but continued to teach courses
at the University of California San Diego as well as at San Diego
State University where he was a Distinguished Visiting Professor in
1972-73.

Carl H FitzGerald, Burton Rodin, and Helmut Rohrl summed up
Warschawski's achievements as follows:-

Steve Warschawski lived among the top mathematicians of two
continents. With careful scholarship, he made lasting contributions to
the theory of complex analysis, particularly to the theory of
conformal mappings. With keen judgment, he guided two mathematics
departments to eminence. With modest gratitude, he cemented many
friendships along the way.

Article by: J J O'Connor and E F Robertson