**Erdos number and other collaboration distances**

The collaboration distance is the publication distance between two given
authors, i.e., given the graph representing the collaboration between authors,
the collaboration distance is the number of edges necessary to reach an author
from another one.

The most famous of such distances is the Erdos number, which indicates the
distance to Paul Erdos.

My Erdos number is 4, and two possible paths are

Alexandre Madureira --> Leopoldo Franca --> Claudio Baiocchi --> Vilmos Komornik

Alexandre Madureira --> Carlo Lovadina --> Claudio Baiocchi --> Vilmos Komornik

It's easy to find any collaboration distance using the ams search
tool.

Some other interesting distances from myself are (the only complete is the list
with distance 1, with my co-authors):

1: Stephan Alessandrini, Doug Arnold, Ferdinando Auricchio, Ana Carius, Richard
Falk, Leo Franca, Carlo Lovadina, Saulo Oliveira, Lutz Tobiska, Fred Valentin,
Sheng Zhang

2: Ivo Babuska, Franco Brezzi, M. Crouzeix, Jim Douglas, Jr., Michel Fortin,
J. Osborn, P. Monk, O. Pironneau

3: Tom Hou, Jaccques-Louis Lions, Pierre-Louis Lions, G.I. Marchuk, Gilber
Strang, Luc Tartar

4: V. Arnold, Philippe G. Ciarlet, Peter Lax, T. Oden, Laurent Schwartz

5: Michael Atiyah, Hugh Brunk, Courant, Kiyosi Ito, Szolem Mandelbrojt, Jacob
Palis, Grigori Perelman (fields medal 2006), Stephen Smale, Terence Tao (fields
medal 2006)

6: Albert Einstein, David hilbert, John Nash, Andrew Wiles, Wendelin Werner (fields medal 2006)

7: John Ball

8: Jane Cronin