Erdős number: Difference between revisions

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Erdos numbers are named for the Hungarian-American mathematician [[Paul Erdos]] and are an application of [[graph theory]], a field in which he published extensively. They treat collaboration among researchers — measured by publication of joint papers — as a graph. A researcher's Erdos number is the length of the shortest path, via co-author relationships, connecting him or her to Paul Erdos.
Erdos numbers are named for the Hungarian-American mathematician [[Paul Erdos]] and are an application of [[graph theory]], a field in which he published extensively. They treat collaboration among researchers — measured by publication of joint papers — as a graph. A researcher's Erdos number is the length of the shortest path, via co-author relationships, connecting him or her to Paul Erdos.


Erdos himself has Erdos number zero. Anyone who is not Erdos but co-authored a paper with him has Erdos number one. In general, if researcher R has co-authors on some papers and some of those have Erdos connections to Erdos, then R's Erdos number is the lowest of the collaborator's numbers, plus one. If there is no chain connecting him or her to Erdos, R's Erdos number is considered infinite.
More explicitly, it is the ''first'' number in the following list which applies to you:
 
* '''0''': You are Paul Erdos .
* '''1''': You have co-authored a paper with Erdos.
* '''N+1''' You have co-authored a paper with some of Erdos number N.
 
If there is no chain of co-author relations connecting you to Erdos, your Erdos number is considered infinite.


There are analogous measures in other fields. Actors calculate their [[Kevin Bacon number]], based on appearing in films together, and [[Go (board game)|Go players]] have a [http://senseis.xmp.net/?ShusakuNumber Shusaku number], the minimum number of games linking them to a great 18th century master.
There are analogous measures in other fields. Actors calculate their [[Kevin Bacon number]], based on appearing in films together, and [[Go (board game)|Go players]] have a [http://senseis.xmp.net/?ShusakuNumber Shusaku number], the minimum number of games linking them to a great 18th century master.


The [http://www.oakland.edu/enp/ The Erdös Number Project] at Oakland University in Rochester, Michigan has much more information.
The [http://www.oakland.edu/enp/ The Erdös Number Project] at Oakland University in Rochester, Michigan has much more information.

Revision as of 08:24, 2 April 2011

Erdos numbers are named for the Hungarian-American mathematician Paul Erdos and are an application of graph theory, a field in which he published extensively. They treat collaboration among researchers — measured by publication of joint papers — as a graph. A researcher's Erdos number is the length of the shortest path, via co-author relationships, connecting him or her to Paul Erdos.

More explicitly, it is the first number in the following list which applies to you:

  • 0: You are Paul Erdos .
  • 1: You have co-authored a paper with Erdos.
  • N+1 You have co-authored a paper with some of Erdos number N.

If there is no chain of co-author relations connecting you to Erdos, your Erdos number is considered infinite.

There are analogous measures in other fields. Actors calculate their Kevin Bacon number, based on appearing in films together, and Go players have a Shusaku number, the minimum number of games linking them to a great 18th century master.

The The Erdös Number Project at Oakland University in Rochester, Michigan has much more information.