I’m an Associate Professor at DTU Informatics, Technical University of Denmark. In the past, I’ve worked as a Postdoctoral Fellow at Institute for Quantitative Social Science at Harvard University and the College of Computer and Information Science at Northeasthern University; before that, I was at Laszlo Barabási’s Center for Complex Network Research at Northeastern University and the Center for Cancer Systems Biology at the Dana Farber Cancer Institute.
I began my career as a physicist, but my interests have shifted towards complex networks and massive datasets, working in the intersection between physics, sociology, and computer science. Recently, I’ve also become interested in data visualization; our related project on visualizing mood on Twitter received world wide press coverage.
My work focuses on understanding the structural and dynamical aspects of complex network topology, as seen from a statistical standpoint. I’m currently working to understand how the temporal dynamics of network edges influence the modular structure found in many social networks. Some of my recent work on that subject was published in Nature (Ahn, Bagrow and Lehmann. Nature doi:10.1038/nature09182, 2010).
Previous work has focused on multipartite networks (Lehmann, Schwartz, Hansen. PRE 78, 016108, 2008) and understanding the type of correlations that scientific authors and collaborations impose on the (citation) links between the publications (Lehmann, Jackson, Lautrup. Nature 444, 1003, 2006). I’m a graduate of the Niels Bohr Institute (B.Sc, Physics 2001 [pdf], M.Sc, Physics, 2003 [pdf]) and the Technical University of Denmark (Ph.D., Complex Networks, 2007 [pdf]).