The file cond-mat-2003.gml contains an updated version of cond-mat.gml, the
collaboration network of scientists posting preprints on the condensed
matter archive at www.arxiv.org.  This version is based on preprints posted
to the archive between January 1, 1995 and June 30, 2003.  The largest
component of this network, which contains 27519 scientists, has been used
by several authors as a test-bed for community-finding algorithms for large
networks; see for example J. Duch and A. Arenas, Phys. Rev. E 72, 027104
(2005).  The network is weighted, with weights assigned as described in
M. E. J. Newman, Phys. Rev. E 64, 016132 (2001).

These data can be cited as either of:

  M. E. J. Newman, The structure of scientific collaboration networks,
  Proc. Natl. Acad. Sci. USA 98, 404-409 (2001).  This paper describes the
  original 1999 version of the network.

  M. E. J. Newman, Fast algorithm for detecting community structure in
  networks, Phys. Rev. E 69, 066133 (2004).  This paper describes the 2003
  version.