Cem Yıldırım

Cem Yalçın Yıldırım (born 8 July 1961) is a Turkish mathematician who specializes in number theory. He obtained his BSc from Middle East Technical University in Ankara, Turkey, and his PhD from the University of Toronto in 1990. His doctoral advisor was John Friedlander. He is a faculty member at Boğaziçi University in Istanbul, Turkey. In 2009, Dan Goldston, János Pintz, and Yıldırım proved that for any positive number ε there exist primes p and p′ such that the difference between p and p′ is smaller than ε log p. This result was originally reported in 2003 by Goldston and Yıldırım but was later retracted. Then Janos Pintz joined the team and they completed the proof in 2005 and developed the so-called GPY sieve.