Erdős number

The Erdős number describes the distance in the graph of co-authorship in relation to the mathematician Paul Erdős. In the graph, the journalistic related authors are represented as nodes, between each of which there exists an edge if they have a publication co-authored. The definition of the Erdős number is likely to return to the analyst Casper Goffman, who wrote in 1969 a scientific article about the collaborations of Erdős. The title of the article was: And what is your Erdős number? ( to German as: " And how high is your Erdős number ?")

According to the definition of the Erdős number Paul Erdős himself has the Erdős number 0, all co-authors, with whom he has written that have Erdős number 1 authors ( but not with Erdős himself) published with co-authors Paul Erdős have, have Erdős number 2, etc. If a connection is produced to a person in this way, the number Erdős is infinite. It turns out that the Erdős number of most people is either infinite or very small - The 268,000 people, for which under the Erdőszahlprojektes a finite value could be determined, have an average Erdős number of 4.65. This is primarily due to Erdős has worked in many areas of mathematics and published together with over 500 different scientists. The basis for the calculation of the respective Erdős number used bibliographic databases that are managed by Erdős number project and updated regularly. On the basis of the Erdős number of each author can be determined.

Of importance for the individual mathematician to calculate the Erdős number is not, even if the graph of the co-authorship is often used to Erdős as an example of graphs of networks in scientific publications. Generally speaking illustrates the Erdős number one aspect of social networks, which is also treated as part of the small-world phenomenon. Other relationships can be defined analogously; The most prominent example is like the Bacon number, which is defined by collaborations among actors.