That figures: Professor who had to work at Subway dazzles world of maths after solving centuries-old prime number riddle

Virtually unknown mathematician Dr Yitang "Tom" Zhang to publish 'landmark' paper on theorem

A university professor who was forced to work at Subway when he couldn't find a job as an academic has solved a prime number riddle that has puzzled the best mathematical brains for centuries.

Dr Yitang Zhang was enjoying the summer holiday in a friend's back garden in Colorado last year when it suddenly occurred to him that he could make a major breakthrough in the field of analytic number theory.

Prime numbers - which are only divisible by one and themselves - often come in pairs that differ by two. Five and seven, for instance, or 11 and 13. They're known as twin primes.

As numbers get larger, it becomes harder to find prime numbers. But for hundreds of years, mathematicians have believed there are an infinite number of these pairs - known as the twin prime conjecture.

While Dr Zhang could not prove that there are an infinite number of twin primes, he has found that there are an infinite number of prime pairs separated by less than 70 million. It may sound like a colossal gap, but he has essentially wrestled that figure down from infinity.

The discovery is all the more remarkable given that Dr Zhang - known as 'Tom' to his students at the University of New Hampshire - was a virtual unknown in the academic world until last month.

He sent his paper to the esteemed Annals of Mathematics journal where it received a glowing peer report and will soon be published following some "minor changes".

"He wasn't a big name, and I get the impression that he wasn't one of the leading analytical number theorists," said Richard Taylor, a respected mathematician and a member of the journal's editorial board. "He's published hardly anything, and it's a steady stream of papers which tends to get you jobs. Maybe he likes to think about the big problems - and you don't solve those very often." It was clear, however, that Dr Zhang had made a "big leap forward".

Dr Zhang had been working on the problem for several years before his eureka moment. but he was incredibly modest about his achievement. "The 70 million figure could be reduced, but I'm not sure by how much," he said. "I was trying to publish the paper [as quickly as possible] so this part - the 70 million - is very rough and there are certain ways to improve it. But I may not do it myself, I may turn my interest to some other problems."

Before finding a job as a professor, he worked at a sandwich chain. "It wasn't bad," he said. "But whenever I was doing it I was thinking about maths."

In the autumn, he'll be giving lectures at Princeton and Harvard, though he can rely on his wife will keep his feet firmly on the ground. She's "not in maths" and "didn't understand" the hullaballoo around what he's doing, he said.

In his spare time, Dr Zhang likes to read Shakespeare (Hamlet and Romeo and Juliet are his favourites, though "everything's good"), but you suspect he won't get time to rest in the near future. In fact, he's already started work on his next project.

Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
ebooks
ebooksA special investigation by Andy McSmith
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Tradewind Recruitment: English Teacher

Negotiable: Tradewind Recruitment: My client is an excellent, large partially ...

Tradewind Recruitment: Science Teacher

£90 - £140 per day: Tradewind Recruitment: I am currently working in partnersh...

Tradewind Recruitment: Year 3 Primary Teacher

£100 - £150 per day: Tradewind Recruitment: Year 3 Teacher Birmingham Jan 2015...

Ashdown Group: Lead Web Developer (ASP.NET, C#) - City of London

£45000 - £50000 per annum + Excellent benefits: Ashdown Group: Lead Web Develo...

Day In a Page

Isis hostage crisis: The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power

Isis hostage crisis

The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power, says Robert Fisk
Missing salvage expert who found $50m of sunken treasure before disappearing, tracked down at last

The runaway buccaneers and the ship full of gold

Salvage expert Tommy Thompson found sunken treasure worth millions. Then he vanished... until now
Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Maverick artist Grayson Perry backs our campaign
Assisted Dying Bill: I want to be able to decide about my own death - I want to have control of my life

Assisted Dying Bill: 'I want control of my life'

This week the Assisted Dying Bill is debated in the Lords. Virginia Ironside, who has already made plans for her own self-deliverance, argues that it's time we allowed people a humane, compassionate death
Move over, kale - cabbage is the new rising star

Cabbage is king again

Sophie Morris banishes thoughts of soggy school dinners and turns over a new leaf
11 best winter skin treats

Give your moisturiser a helping hand: 11 best winter skin treats

Get an extra boost of nourishment from one of these hard-working products
Paul Scholes column: The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him

Paul Scholes column

The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him
Frank Warren column: No cigar, but pots of money: here come the Cubans

Frank Warren's Ringside

No cigar, but pots of money: here come the Cubans
Isis hostage crisis: Militant group stands strong as its numerous enemies fail to find a common plan to defeat it

Isis stands strong as its numerous enemies fail to find a common plan to defeat it

The jihadis are being squeezed militarily and economically, but there is no sign of an implosion, says Patrick Cockburn
Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action

Virtual reality: Seeing is believing

Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action
Homeless Veterans appeal: MP says Coalition ‘not doing enough’

Homeless Veterans appeal

MP says Coalition ‘not doing enough’ to help
Larry David, Steve Coogan and other comedians share stories of depression in new documentary

Comedians share stories of depression

The director of the new documentary, Kevin Pollak, tells Jessica Barrett how he got them to talk
Has The Archers lost the plot with it's spicy storylines?

Has The Archers lost the plot?

A growing number of listeners are voicing their discontent over the rural soap's spicy storylines; so loudly that even the BBC's director-general seems worried, says Simon Kelner
English Heritage adds 14 post-war office buildings to its protected lists

14 office buildings added to protected lists

Christopher Beanland explores the underrated appeal of these palaces of pen-pushing
Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Scientists unearthed the cranial fragments from Manot Cave in West Galilee