**Alessandro Vespignani** is an Italian physicist and Sternberg Distinguished Professor of Physics, Computer Science and Health Sciences at Northeastern University.

Vespignani is known for his work on complex networks, and particularly for work on the applications of network theory to the spread of disease and for studies of the topological properties of the Internet. He is author, together with Romualdo Pastor-Satorras, of the book *Evolution and Structure of the Internet*. Together with Alain Barrat and Marc Barthelemy he has published in 2008 the monograph *Dynamical Processes on Complex Networks*. He is currently completing a book on *Self-organized criticality and avalanche phenomena* with S. Zapperi for Oxford University Press. Vespignani is an elected fellow of the American Physical Society, an elected member of the Academia Europaea, and is serving in the board/leadership of a variety of professional associations, institutions and journals.

Alessandro Vespignani received his undergraduate degree and Ph.D., both in physics and both from the University of Rome “La Sapienza”, in 1990 and 1993 respectively. Following postdoctoral research at Yale University and Leiden University, he worked at the International Center for Theoretical Physics in Trieste for five years, and briefly at the University of Paris-Sud, before moving to Indiana University in 2004 and then to Northeastern University in 2010. Vespignani has worked in a number of areas of physics, including characterization of non-equilibrium phenomena and phase transitions, and collaborated with, among others, Luciano Pietronero and Benoit Mandelbrot. He is best known, however, for his work on complex networks. He describes his current research as being focused on "interdisciplinary application of statistical and numerical simulation methods in the analysis of epidemic and spreading phenomena and the study of biological, social and technological networks."

Of particular note is his work with Romualdo Pastor-Satorras in which the two demonstrated that for a disease propagating on a random scale-free network the transmission probability or infectivity necessary to sustain an outbreak tends to zero in the limit of large network size. In practice this means that such a disease will never die out, no matter what steps are taken to reduce the probability of its transmission between individuals.

R. Pastor-Satorras & A. Vespignani (2001). "Epidemic spreading in scale-free networks". *Physical Review Letters*. **86** (14): 3200–3203. Bibcode:2001PhRvL..86.3200P. PMID 11290142. arXiv:cond-mat/0010317 . doi:10.1103/PhysRevLett.86.3200.
R. Pastor-Satorras; A. Vazquez & A. Vespignani (2001). "Dynamical and correlation properties of the Internet". *Physical Review Letters*. **87** (25): 258701. Bibcode:2001PhRvL..87y8701P. PMID 11736611. arXiv:cond-mat/0105161 . doi:10.1103/PhysRevLett.87.258701.
A. Barrat; M. Barthélemy; R. Pastor-Satorras & A. Vespignani (2004). "The architecture of complex weighted networks". *PNAS*. **101** (11): 3747–3752. Bibcode:2004PNAS..101.3747B. PMC 374315 . PMID 15007165. arXiv:cond-mat/0311416 . doi:10.1073/pnas.0400087101.
Pastor-Satorras, R.; Vespignani, A. (2004). *Evolution and Structure of the Internet*. Cambridge University Press. ISBN 0-521-82698-5.
Barrat, A.; Barthelemy, M.; Vespignani, A. (2008). *Dynamical processes on complex networks*. Cambridge University Press. ISBN 0-521-87950-7.