Contrary to what mathematicians had long expected, the announced proof didn’t need to introduce any new concepts — it instead unearthed hidden connections between old ones. “The proof is a surprising synthesis of well-known ideas,” said Alexander Dunn of the Georgia Institute of Technology.

The result relied in part on techniques pioneered by Dunn and New York University's Maksym Radziwiłł. Alongside other number theorists, they have been working to understand the proof and what it could mean. Now they’re starting to get answers.