A reclusive Russian mathematician who was recently awarded $1 million for solving a problem almost 100 years old said Tuesday he is not sure if he will accept the prize.
A children's charity and communist group have suggested that the money should be donated to them.
The Clay Mathematics Institute in Cambridge, Mass., announced last week that Grigori Perelman would be awarded a million-dollar Millennium Prize for solving the famous Poincaré conjecture, a problem first posed in 1904 by mathematician and physicist Henri Poincaré that has stumped mathematicians for generations.
"I have not yet made a decision," Perelman said, according to a recording of a phone call with him posted by the Russian Web site LifeNews.ru.
"If I decide, the Clay Institute, which established the prize, will be the first to know," he continued. "But so far nothing has been decided."
The Warm Home children's charity in St. Petersburg wrote Perelman an open letter Tuesday, asking him to donate the money to Russian charities.
"Unfortunately, unlike in the case of mathematical problems, no universal approach can be found toward solving human problems. Each suffering child and each mother entangled in circumstances of her life could receive help," the chairwoman of the charity wrote.
Communist activists in St. Petersburg were more aggressive in their request, responding to an earlier report that Perelman would not be accepting the money. They proposed to use it to build a research facility and support the Lenin Mausoleum in Moscow.
"We are willing to explain to him that, if he does not take the money, it will be spent on American scientists working on nuclear weapons," the leader of the St. Petersburg and Leningrad Region Communists told the Interfax news agency.
The Poincaré conjecture is one of math's most difficult and important theorems, and a key to the three-dimensional study of topology. It says, in essence, that unless an object has a hole, it is considered a sphere.
Perelman started posting sketches of a proof of the Poincaré conjecture online in late 2002. It was then studied for the next several years by teams of mathematicians who eventually determined he was correct.
Perelman gave lectures at a few top American universities in the spring of 2003 but soon returned to Russia and appeared to sever ties with the academic world, reportedly leaving St. Petersburg's Steklov Institute of Mathematics and living with his mother.
In 2006, Perelman was awarded the Fields Medal, one of math's highest honors given out every four years and often compared to the Nobel Prize. He declined it, telling the Guardian at the time, "I do not think anything that I say can be of the slightest public interest."
"I am not saying that because I value my privacy, or that I am doing anything I want to hide," he said. "I know that self-promotion happens a lot, and if people want to do that, good luck to them, but I do not regard it as a positive thing."
John Ball, head of the International Mathematical Union in 2006, went to St. Petersburg to try to understand Perelman's decision and told the BBC that Perelman "has a different psychological makeup, which makes him see life differently."
In 2000, the Clay Mathematical Institute established seven seperate $1 million prizes, known as the Millennium Prizes, "to record some of the most difficult problems with which mathematicians were grappling at the turn of the second millennium."
The president of the institute, James Carlson, said in a statement that Perelman was awarded the first of the seven prizes because his work "brings to a close the century-long quest for the solution. It is a major advance in the history of mathematics that will long be remembered."
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