Helmut Röhrl or Rohrl (born 22 March 1927 in

Straubing Straubing (; Central Bavarian: ''Strauwing'') is an independent city in Lower Bavaria, southern Germany. It is seat of the Districts of Germany, district of Straubing-Bogen. Annually in August the Gäubodenvolksfest, the second largest fair in Ba ...

, died 30 January 2014) was a German mathematician. Besides

complex analysis Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates functions of complex numbers. It is helpful in many branches of mathematics, including algebraic ...

(including among other subjects the Riemann–Hilbert problem), he worked on algebra and

category theory Category theory is a general theory of mathematical structures and their relations. It was introduced by Samuel Eilenberg and Saunders Mac Lane in the middle of the 20th century in their foundational work on algebraic topology. Category theory ...

and

totally convex space Totally may refer to: * ''Totally'' (album), album by German band Bad Boys Blue *Totally (company), publishing company *Totally Games, video game developer See also * ''La Totale! ''La Totale!'' (, a French expression roughly meaning " the w ...

s. In 1964 he edited the new edition of the classic textbook on complex analysis by

Adolf Hurwitz Adolf Hurwitz (; 26 March 1859 – 18 November 1919) was a German mathematician who worked on algebra, mathematical analysis, analysis, geometry and number theory. Early life He was born in Hildesheim, then part of the Kingdom of Hanover, to a ...

and

Richard Courant Richard Courant (January 8, 1888 – January 27, 1972) was a German-American mathematician. He is best known by the general public for the book '' What is Mathematics?'', co-written with Herbert Robbins. His research focused on the areas of real ...

. Röhrl received his doctorate in 1949 at the

Ludwig-Maximilians-Universität München The Ludwig Maximilian University of Munich (simply University of Munich, LMU or LMU Munich; ) is a public university, public research university in Munich, Bavaria, Germany. Originally established as the University of Ingolstadt in 1472 by Duke ...

under

Robert König Robert Johann Maria König (11 April 1885, Linz – 9 July 1979, Munich) was an Austrian mathematician. He studied from 1903 to 1907 at the University of Vienna and at the University of Göttingen, where he received his PhD under David Hilb ...

(and

Oskar Perron Oskar Perron (7 May 1880 – 22 February 1975) was a German mathematician. He was a professor at the University of Heidelberg from 1914 to 1922 and at the University of Munich from 1922 to 1951. He made numerous contributions to differentia ...

) with doctoral thesis ''Über Differentialsysteme, welche aus multiplikativen Klassen mit exponentiellen Singularitäten entspringen''published in 3 parts, ''Mathematische Annalen'', vol. 123, 1951, pp. 53–75; vol. 124, 1952, pp. 187–218; vol. 125, 1953, pp. 448–466 and his

habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excelle ...

in 1953 with habilitation thesis ''Abelsche Integrale auf Riemannschen Flächen endlichen Geschlechts''. He was a

docent The term "docent" is derived from the Latin word , which is the third-person plural present active indicative of ('to teach, to lecture'). Becoming a docent is often referred to as habilitation or doctor of science and is an academic qualifi ...

in mathematics from 1949 to 1951 in Würzburg, from 1951 to 1953 in Munich, from 1953 to 1955 in Münster under Heinrich Behnke and from 1955 to 1958 again in Munich. In the academic year 1958–1959 he was at the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

, became in 1959 an associate professor and subsequently professor at the

University of Minnesota The University of Minnesota Twin Cities (historically known as University of Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Twin Cities of Minneapolis and Saint ...

and was from 1964 a professor at the

University of California, San Diego The University of California, San Diego (UC San Diego in communications material, formerly and colloquially UCSD) is a public university, public Land-grant university, land-grant research university in San Diego, California, United States. Es ...

. In the academic 1962–1963 Röhrl was a visiting professor at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

, in 1967–1968 at

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

, in 1972–1973 at the University of Munich, and at the

University of Fribourg The University of Fribourg (; ) is a public university located in Fribourg, Switzerland. The roots of the university can be traced back to 1580, when the notable Jesuit Peter Canisius founded the Collège Saint-Michel in the City of Fribourg ...

, the

FernUniversität Hagen The University of Hagen (, informally often referred to as FU Hagen) is a public research university that is primarily focused on distance teaching. While its main campus is located in Hagen, North Rhine-Westphalia, Germany, the university ma ...

, the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, and the

Technical University Munich The Technical University of Munich (TUM or TU Munich; ) is a Public university, public research university in Munich, Bavaria, Germany. It specializes in engineering, technology, medicine, and applied science, applied and natural sciences. Est ...

, and in 1976 at the

University of Nagoya , abbreviated to or NU, is a Japanese national research university located in Chikusa-ku, Nagoya. It was established in 1939 as the last of the nine Imperial Universities in the then Empire of Japan, and is now a Designated National University ...

Works

*Das Riemann-Hilbert’sche Problem der linearen Differentialgleichungen, Mathematische Annalen, vol. 133, 1957, pp. 1–25. *as annotator and editor:

''Lehrbuch der Funktionentheorie'', Springer Verlag, 4th edn. 1964 **annotations (pp. 551–696) forming two new chapters: ''Weitere Abbildungstheoreme der Funktionentheorie'' (including quasiconformal mappings) and ''Holomorphe und meromorphe Funktionen auf Riemannschen Flächen'' (including the Riemann–Roch theorem, Runge approximation theorem, topology and vector bundles on

Riemann surface In mathematics, particularly in complex analysis, a Riemann surface is a connected one-dimensional complex manifold. These surfaces were first studied by and are named after Bernhard Riemann. Riemann surfaces can be thought of as deformed vers ...

s, and automorphe functions) * *with Dieter Pumplün: ''Banach spaces and totally convex spaces'', parts 1, 2, Comm. in Algebra, vol. 12, 1984, pp. 935–1019; vol. 13, 1985, pp. 1047–1113

References

External links

Homepage at the UCSD
{{DEFAULTSORT:Rohrl, Helmut 20th-century German mathematicians People from Straubing 1927 births 2014 deaths Academic staff of the Technical University of Munich University of California, San Diego faculty