My Erdös Number

Apparently my Erdös number is 5. The shortest coauthorship path that I know of, between Erdös and myself, is listed below. More information about Erdös numbers can be found at My thanks to Jerry Grossman for maintaining the Erdös database and providing me with some parts of the path below.

In case you're not familiar with Erdös numbers, here is a brief introduction. Paul Erdös was one of the most brilliant and prolific mathematicians of the 20th century. He authored or coauthored (mostly the latter) about 1500 papers. In so doing, he encouraged and promoted the system of collaboration and coauthorship that has become much more commonplace in recent years; far fewer mathematical papers today are written by a single author. ... Erdös was also one of the most egotistical mathematicians of the 20th century. He described anyone who coauthored a paper with him as having "Erdös number 1"; anyone who coauthored a paper with one of those people had "Erdös number 2"; and so on. Following is my path to Erdös:

Paul Erdös and Geza Freud: On orthogonal polynomials with regularly distributed zeros. Proc. London Math. Soc. (3) 29 (1974), 521-537. MR 54 #8134. Geza Freud and Janos Bognar: Berechnung der gequantelten Energiewerte eines im elektrischen Felde rotierenden Dipols. (Hungarian. Russian, German summary) Magyar Tud. Akad. Alkalm. Mat. Int. Közl. 3 (1954), 239--251 (1955). MR 17,852e. Janos Bognar and Paul A. Binding (also with T. Ja. Azizov and B. Najman): Nondegenerate Jordan subspaces of selfadjoint operators in indefinite spaces. (English. English summary) Linear Algebra Appl. 207 (1994), 37-48. MR 96c:15003. D. C. Biles and P. A. Binding: On Carathéodory's conditions for the initial value problem. Proc. Amer. Math. Soc. 125 (1997), no. 5, 1371-1376. MR 97g:34008. Daniel C. Biles and Eric Schechter: Solvability of a finite or infinite system of discontinuous quasimonotone differential equations, Proc. Amer. Math. Soc. 128 (2000), 3349-3360.