Yitang Zhang

Yitang Zhang was born in Shanghai; the Cultural Revolution interrupted his schooling, and he worked as a labourer for a decade before entering Peking University in 1978, earning bachelor's (1982) and master's (1984) degrees there. He moved to the United States in 1985 for a PhD at Purdue University, completed in 1991 under Tzuong-Tsieng Moh, but struggled afterward to find an academic position and spent years working outside mathematics, including as an accountant, before a former classmate helped him secure a lectureship at the University of New Hampshire in 1999.

Working largely outside the mathematical mainstream, Zhang continued research on his own. In 2013, at age 58 and still a lecturer, he submitted "Bounded Gaps Between Primes" to the Annals of Mathematics, proving that there are infinitely many pairs of primes differing by less than 70 million — the first proof that prime gaps do not grow without bound infinitely often, a major advance toward the twin prime conjecture (that infinitely many primes $p$ have $p+2$ also prime). The bound was rapidly improved by a Polymath collaborative project and by James Maynard's independent, more flexible sieve method later that year.

Zhang's result brought him sudden international recognition after decades of obscurity. He was promoted to professor at New Hampshire, moved to the University of California, Santa Barbara, in 2015, and received the MacArthur Fellowship, the Cole Prize, and the Rolf Schock Prize, all in 2014.

Workplaces: University of New Hampshire, University of California, Santa Barbara

China, United States

Contributions, linked to the library