Yitang Zhang

Yitang Zhang (张益唐, born February 5, 1955) is a celebrated Chinese-American number theorist who left the University of California, Santa Barbara in summer 2025 to join Sun Yat-sen University's Hong Kong Institute of Advanced Study as a professor, becoming emeritus at UCSB. Now 70, Zhang rose from years of obscurity — including stints working in a Subway sandwich shop and a Kentucky motel — to global mathematical fame in 2013.

Zhang earned his bachelor's and master's degrees in mathematics from Peking University before completing his PhD at Purdue University in 1991 under Tzuong-Tsieng Moh. After struggling for years to secure an academic position, he was working as a lecturer at the University of New Hampshire when, in 2013, he submitted a landmark paper to the Annals of Mathematics proving the first finite bound on gaps between consecutive prime numbers — a major breakthrough toward the twin prime conjecture. The achievement earned him the Ostrowski Prize, the Cole Prize, the Rolf Schock Prize, and a 2014 MacArthur "genius" Fellowship, and led to his appointment at UC Santa Barbara in 2015.

Asked why he returned to China at 70, Zhang said he hoped to pass down decades of accumulated mathematical insight and "mentor a group of young talents," adding that he views China's scientific capabilities as undergoing a qualitative transformation that makes it one of the most conducive environments for basic research in the world today. He continues to work on the Landau-Siegel zeros conjecture, a problem related to the Riemann hypothesis.