MAE and CS professor Raissa D’Souza was honored twice by the Network Science Society, being named a Fellow of the society and receiving the inaugural Euler Award for an outstanding research contribution that changed paradigms or assumptions in the field.
D’Souza, who holds a joint appointment in the CS and MAE departments, studies the mathematics of networks, developing models to understand the dynamics of networks and the dynamics of processes unfolding on networks. She is particularly interested in how local interactions between nodes lead to large-scale self-organized behaviors.
Her work is multidisciplinary, as she collaborates with physicists, mathematicians, animal scientists, engineers, political scientists and sociologists to apply her mathematical models to networks in all parts of life. Much of her recent work has been as the leader of a Multidisciplinary University Research Initiative (MURI) that looks to predict and control behaviors of systems made up of interdependent networks.
“Many of the really exciting things in the world around us are highly interdisciplinary,” she told Peter Smith of the California Aggie. “We need sociologists and engineers and mathematicians and physicists, and philosophers and artists all working together to solve problems.”
D’Souza was named the inaugural Euler Award winner for her discovery and breakthrough research on explosive percolation in networks.
One basic aspect of any network is the extent of connectivity it supports. A large collection of nodes with just a small number of edges can only have small clusters of connectivity. If more edges connecting nodes together are added to the system at random, the network eventually hits a tipping point where adding just a few more edges causes a single large cluster to spontaneously emerge that slowly encompasses the full system.
In a 2009 paper, D’Souza and her co-authors introduced a small tweak to this edge-addition process that repeatedly made a simple, local intervention that ultimately causes the significant delay of this large-scale connectivity and leads to the extremely abrupt and punctuated “explosion” of large-scale connectivity with dramatically different features.
“This was something so radically new that it opened up a new field,” said postdoctoral scholar Marton Posfai, who has worked with D’Souza for the last five years. “It completely changed the nature of the transition [to connectivity].”
At the same conference, she was also named a Fellow of the organization, one of seven members to be recognized for overall contributions to the field and to the community.
D’Souza is also a Fellow of the American Physical Society and she served as the President of the Network Science Society from 2015-2018. She received her B.S. in Physics at the University of Illinois and her Ph.D. in Statistical Physics at MIT before completing postdocs at Bell Laboratories and Microsoft Research. She has been at UC Davis since 2005.
D’Souza received the honors at the 2019 Network Science Society Conference (NetSci 2019) from May 27-31 in Burlington, VT.