Mathematician who solved prime-number riddle claims new breakthrough

Number theorist Yitang Zhang, who went from obscurity to luminary status in 2013 for cracking a century-old question about prime numbers, now claims to have solved another. The problem is similar to — but distinct from — the Riemann hypothesis, which is considered one of the most important problems in mathematics. Zhang posted his proposed solution — a 111-page preprint — on arXiv, and it has not yet been validated by his peers. If it checks out, it will help to tame the randomness of prime numbers, but Zhang and other scientists have previously proposed solutions to this problem that turned out to be faulty. It will take a while for researchers to comb through Zhang’s argument to see whether it is correct.