- Lived:
- born 20 May 1966, by most accounts in Allahabad (Prayagraj); the life has happened almost entirely on one campus — IIT Kanpur, where he studied, taught, proved his theorem, and now serves as Director
- Field:
- theoretical computer science and mathematics — computational complexity, the study of what can be computed fast
- The Big Idea:
- With two students who had just finished their bachelor's degrees, he proved in August 2002 that there is a guaranteed, always-correct, provably fast way to tell whether any number is prime — settling a question mathematicians had worried at since Gauss.
- In their words:
- "PRIMES is in P" — the four-word title of the paper, which is also its entire claim (as of September 2026)
- If you remember one thing:
- A professor and two undergraduates, working inside an Indian institution on an Indian salary, closed one of the oldest open problems in mathematics with nine pages of algebra — and the answer was checked and celebrated around the world within a week.