Top mathematician chooses to live a modest life away from the limelight
Five years ago one of the world's biggest unsolved mathematical mysteries was confirmed to have been cracked by a Russian mathematician.
Grigory Perelman had quietly posted his answer online in 2002.
But, instead of being feted by the world's top universities, Perelman has shunned all publicity, awards and prize money and opted instead to live very modestly with his mother in St Petersburg.
Glynn Goffin reports.