**Erdős** posed and solved problems in number theory and other areas and founded the field of discrete mathematics.

- This naturally had the effect making Lajos and Anna extremely protective of Paul.
- He quickly moved against those perceived as Communists and Anna Erdős fell into that category due to her failing to obey the Communist strike call when Kun was in power.
- He now set about teaching Paul to speak English, but the strange English accent which this gave Paul remained one of his characteristics throughout his life.
- Despite the restrictions on Jews entering universities in Hungary, Erdős, as the winner of a national examination, was allowed to enter in 1930.
- During his tenure of the fellowship, Erdős travelled widely in the UK.
- His friendship with Ulam was to prove important later when Erdős was in the United States.
- In March 1938 Hitler took control of Austria and Erdős had to cancel his intended spring visit to Budapest.
- Within weeks Erdős was on his way to the USA where he took up a fellowship at Princeton.
- He hoped for his fellowship to be renewed but Erdős did not conform to Princeton's standards so he was offered only a six month extension rather than the expected year.
- and Ulam invited Erdős to visit Madison to help out.
- We shall return later to give further details of the strange life which Erdős lived from this time on, devoted exclusively to seeking out and solving good mathematical problems.
- The contributions which Erdős made to mathematics were numerous and broad.
- However, basically Erdős was a solver of problems, not a builder of theories.
- To Erdős the proof had to provide insight into why the result was true, not just provide a complicated sequence of steps which would constitute a formal proof yet somehow fail to provide any understanding.
- Some results with which Erdős is most closely associated had been first proved before Erdős was born.
- Chebyshev proved Bertrand's conjecture in 1850 but when Erdős was only an eighteen year old student in Budapest he found an elegant elementary proof of this result.
- In 1949 Erdős and Atle Selberg found an elementary proof.
- Erdős was not much concerned with the competitive aspect of mathematics and was philosophical about the episode.
- This result was typical of the type of mathematics Erdős worked on.
- Erdős did receive the Cole Prize of the American Mathematical Society in 1951 for his many papers on the theory of numbers, and in particular for the paper On a new method in elementary number theory which leads to an elementary proof of the prime number theorem published in the Proceedings of the National Academy of Sciences in 1949.
- Whether a rather silly event which took place in August 1941 was to have any real effect on Erdős's life, or whether it was simply used as an excuse, is hard to tell.
- Erdős and two fellow mathematicians were picked up by the police near a military radio transmitter on Long Island.
- He asked Erdős to join the project but, although he was interested enough to be interviewed, Erdős gave answers to those interviewing him which he must have known were not what they wanted to hear.
- Erdős was simply too honest in saying that he would wish to return to Budapest at the end of the war.
- This episode does give the feeling that Erdős never wanted to work at Los Alamos, but was simply amusing himself.
- In 1943 Erdős worked at Purdue University, taking a part-time appointment.
- It is unlikely that the full extent of the horror was understood by Erdős in the United States at the time.
- It was an inspired offer which gave Erdős complete freedom to rush off to do some joint research whenever he wanted.
- Erdős could not bring himself to accept the same generous offer on a permanent basis, which both the University of Notre Dame and Erdős's friends tried hard to encourage him to accept.
- Erdős began to come under suspicion from authorities who saw imaginary problems everywhere.
- Erdős was not allowed back to the United States but no reason was given.
- By this time, however, Erdős had become a traveller moving from one university to another, and from the home of one mathematician to another.
- Erdős and Graham met at a number theory conference in 1963 and soon began a mathematical collaboration.
- It was Graham who provided a room in his house where Erdős could live when he wanted, he also stored Erdős's papers there and, in many ways, acted as a secretary to Erdős.
- Erdős won many prizes including the Wolf Prize of 50 000 dollars in 1983.
- Erdős is somewhat below medium height, an extremely nervous and agitated person.

Born 26 March 1913, Budapest, Hungary. Died 20 September 1996, Warsaw, Poland.

View full biography at MacTutor

Analysis, Origin Hungary, Prize Wolf

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive