Lars Ahlfors

Lars Ahlfors was a Finnish mathematician who lived from 1907 to 1996 and became the leading figure in complex analysis during the twentieth century. Born in Helsinki, he studied at the University of Helsinki under Ernst Lindelöf and Rolf Nevanlinna and completed his doctorate there in 1930, after publishing in 1929 the first proof of Denjoy's conjecture on the asymptotic values of entire functions. His mature work centred on Riemann surfaces, quasiconformal mappings and Teichmüller spaces, and he wrote a textbook on complex analysis that became a standard text. In 1936 he was one of the first two people awarded the Fields Medal, sharing it with the American mathematician Jesse Douglas, and in 1981 he received the Wolf Prize in Mathematics.