The Hep-Th dataset.

A collaboration network of scientists posting preprints on the high-energy theory archive at www.arxiv.org, 1995-1999, as compiled by M. Newman.

M. E. J. Newman, The structure of scientific collaboration networks, Proc. Natl. Acad. Sci. USA 98, 404-409 (2001).
M. E. J. Newman, Scientific collaboration networks: I. Network construction and fundamental results, Phys. Rev. E 64, 016131 (2001).
M. E. J. Newman, Scientific collaboration networks: II. Shortest paths, weighted networks, and centrality, Phys. Rev. E 64, 016132 (2001).