Leila Sloman in Quanta:
On Sunday, February 5, Olof Sisask and Thomas Bloom received an email containing a stunning breakthrough on the biggest unsolved problem in their field. Zander Kelley, a graduate student at the University of Illinois, Urbana-Champaign, had sent Sisask and Bloom a paper he’d written with Raghu Meka of the University of California, Los Angeles. Both Kelley and Meka were computer scientists, an intellectual world apart from the additive combinatorics that Sisask and Bloom study.
“My mind was just blown. Like, wait, have they really done this?” said Sisask, a lecturer at Stockholm University. Kelley and Meka, outsiders to the field of combinatorics, said they had found a new — and dramatically lower — limit on the size of a set of integers in which no three of them are evenly spaced (ruling out combinations like 3, 8 and 13 or 101, 201 and 301).