Hans-Egon Richert

Hans-Egon Richert (2 June 1924 to 25 November 1993) was a German mathematician who worked primarily in analytic number theory and is the author, with Heini Halberstam, of a definitive book on sieve theory. Born in Hamburg, he attended the University of Hamburg and received his doctorate under Max Deuring in 1950. He held a temporary chair at the University of Göttingen, then a newly created chair at the University of Marburg, and in 1972 moved to the University of Ulm, where he remained until his retirement in 1991. His contributions include work on additive number theory, Dirichlet series, Riesz summability and exponential sums, and he proved the exponent 15/46 for the Dirichlet divisor problem. For many years he chaired the Analytic Number Theory meetings at Oberwolfach.