He is a Norwegian [[mathematician]] who, in 1948, provided a long-awaited elementary proof of the prime number theorem, around the same time that [[Paul Erdős]] provided an independent proof. He immigrated to the United States and works at the Institute for Advanced Study in [[Princeton University|Princeton]]. | He is a Norwegian [[mathematician]] who, in 1948, provided a long-awaited elementary proof of the prime number theorem, around the same time that [[Paul Erdős]] provided an independent proof. He immigrated to the United States and works at the Institute for Advanced Study in [[Princeton University|Princeton]]. |