Lars Ahlfors

Lars Valerian Ahlfors (18 April 1907 – 11 October 1996) was a Finnish mathematician and the leading figure in complex analysis during the 20th century. He is remembered for his work on Riemann surfaces, quasiconformal mappings and Teichmüller spaces, and for his textbook on complex analysis. In 1936 Ahlfors was one of the first two recipients of the Fields Medal, along with American mathematician Jesse Douglas, and in 1981 he received the Wolf Prize in Mathematics.

Biography

Early life and education Ahlfors was born in Helsinki, Finland. His mother, Sievä Helander, died at his birth. His father, Karl Axel Mauritz Ahlfors, was a professor of engineering at the Helsinki University of Technology. He completed his doctorate from the University of Helsinki in 1930.

Academic career Ahlfors began his academic career at Åbo Akademi and was appointed associate professor of mathematics at the University of Helsinki in 1933. He was awarded the Wihuri International Prize in 1968 and the Wolf Prize in Mathematics in 1981, whose citation concluded that every function theorist active at the time was in some measure a student of Ahlfors. and Conformal invariants (1973). He made decisive contributions to meromorphic curves, value distribution theory, Riemann surfaces, conformal geometry, quasiconformal mappings and other areas during his career.

In 1954 Ahlfors proved that the results and conjectures of Oswald Teichmüller — whose pioneering work on Riemann surfaces had been cut short when he disappeared on the German Eastern Front in 1943 — were correct. In doing so he defined the concept of Teichmüller space, which rapidly became an important field of research within function theory and later acquired significance in physics as well. His work made the theory of quasiconformal mappings a central area of complex analysis, and by the year 2000 this theory was assessed as perhaps the most important advance in function theory during the 20th century. Ahlfors, Lars V. Conformal invariants. Topics in geometric function theory. Reprint of the 1973 original. With a foreword by Peter Duren, F. W. Gehring and Brad Osgood. AMS Chelsea Publishing, Providence, RI, 2010. xii+162 pp. Ahlfors, Lars V. Lectures on quasiconformal mappings. Second edition. With supplemental chapters by C. J. Earle, I. Kra, M. Shishikura and J. H. Hubbard. University Lecture Series, 38. American Mathematical Society, Providence, RI, 2006. viii+162 pp. Ahlfors, Lars V. Möbius transformations in several dimensions. Ordway Professorship Lectures in Mathematics. University of Minnesota, School of Mathematics, Minneapolis, Minn., 1981. ii+150 pp. Ahlfors, Lars V.; Sario, Leo. Riemann surfaces. Princeton Mathematical Series, No. 26 Princeton University Press, Princeton, N.J. 1960 xi+382 pp.