ROTH, KLAUS FRIEDRICH

born Oct. 29, 1925, Breslau, Ger. [now Wroclaw, Pol.] German-born British mathematician who was awarded the Fields Medal in 1958 for his work in number theory. Roth attended Peterhouse College, Cambridge, Eng. (B.A., 1945), and the University of London (M.Sc., 1948; Ph.D., 1950). From 1948 to 1966 he held an appointment at University College, London, then became professor of pure mathematics at Imperial College of Science, Technology and Medicine, London, a position he held until 1988. Roth was awarded the Fields Medal at the International Congress of Mathematicians in Edinburgh in 1958. His major work has been in number theory, particularly the analytic theory of numbers, and the work that led to his receiving the Fields Medal had to do with rational approximations to algebraic numbers. If a is any irrational number, algebraic or not, there are infinitely many rational numbers p/q such that | p/q - a |