Topology of force networks in compressed granular media L. Kondic, A. Goullet, C. S. O'Hern, M. Kramar, K. Mischaikow and R. P. Behringer EPL, 97 5 (2012) 54001 Published online: 28 February 2012 DOI: 10.1209/0295-5075/97/54001