Yu Jianchun, a migrant worker, gave a presentation at Zhejiang Univeristy, last month.

Story highlights

Chinese migrant worker Yu Jianchun may be a maths genius

He has not received any professional training

His solution to complex math problem has amazed academics

Beijing CNN  — 

A Chinese migrant worker with no college degree has found a solution to a complex math problem – in what appears to be a real life version of the Oscar-winning movie “Good Will Hunting.”

Yu Jianchun, who works for a parcel delivery company, said he’d always had a passion for numbers and has created an alternative method to verify Carmichael numbers.

His solution amazed academics, who said his proof was much more efficient than the traditional one.

“It was a very imaginative solution,” said Cai Tianxin, a math professor at Zhejiang University.

“He has never received any systematic training in number theory nor taken advanced math classes. All he has is an instinct and an extreme sensitivity to numbers.”

Carmichael numbers are sometimes described as “pseudo primes” – they complicate the task of determining true prime numbers, which are divisable only by 1 and itself. They play an important role in computer science and information security.

Yu worked on his proof during his free time while building a new home in his village last year.

“I was overwhelmed with joy, because my solution was completely different to the classic algorithm,” said Yu.

Yu Jianchun sent a letter in May  to Professor Cai Tinxin of Zhejiang University.

Exciting discovery

William Banks, a mathematician at the University of Missouri, who works with Carmichael numbers said, if verified, an alternative proof would be an exciting discovery for his field.

He said that the only construction of an infinite family of Carmichael number was done by academics 20 years ago.

“There have been additional theoretical results in this area – including several by myself and my co-authors – but these are all variations on a theme,” he said.

Yu presented his proof – along with solutions to four other problems – to the public on June 13 at a graduate student seminar on the invitation of Cai.

However, it took Yu more than eight years of writing letters to prominent Chinese mathematicians to get any recognition for his talent.

Cai, the professor, says he will include Yu’s solution in an upcoming book.

Yu worked on his proof during his free time while building a new home in his village.

‘I’m slow-witted’

Yu, who describes himself as shy and introverted, said he would pore over numbers with a calculator while he studied animal breeding at a vocational school.

“I was extremely nervous during the presentation,” Yu told CNN. “So nervous that I wrote wrong numbers on the blackboard.”

Yu only studies numbers in his free time and says he has never considered full-time professional study. He attributed his talent to diligence and solitude. He’s also modest.

“I’m slow-witted,” he says. “I need to spend far more time studying math problems than others. Although I am sensitive to numbers, I barely have any knowledge about calculus or geometry.”

After local and national media reported on his findings, Yu has become a local celebrity. A company that manufactures silk products has offered him a less labor-intensive job to give him more time to study math.

Yu had never heard of the movie “Good Will Hunting,” but says he’s curious to see it.

The 1997 drama, which stars Matt Damon and Robin Williams, tells the fictional story of a maths genius who works as a janitor at the Massachusetts Institute of Technology.

Slightly overwhelmed by his sudden fame, Yu said he is nevertheless grateful for the new opportunities that hopefully lie ahead.

However, at age 33 and still single, he says his primary concern is to get married.

“I want to have my own family first and then comes math.”