Networks arise pervasively in biology, physics, technology, social science, and myriad other areas. Traditionally, a network consists of a static collection of entities (called nodes) that interact via a single type of edges. However, most networks included multiple types of connections --- which could represent, for example, Facebook friendships and Twitter following --- and the nodes and/or edges can also change in time. To incorporate such structure into investigations of networks, my collaborators and I have developed a tensorial formalism to study so-called "multilayer networks". In this talk, I will give an introduction to multilayer networks and discuss some applications of our work. The main reference for this talk is our new review article, which is available at http://comnet.oxfordjournals.org/content/2/3/203.

Mason A. Porter is a Professor of Nonlinear and Complex Systems at the Oxford Centre for Industrial and Applied Mathematics in the Mathematical Institute of the University of Oxford. He previously held postdoc positions at Georgia Tech, MSRI, and Caltech after receiving his Ph.D. from Cornell University. Dr. Porter's research interests lie in statistical and nonlinear physics and in the application of such techniques to the physical, engineering, social, and biological sciences. He has research papers on topics including nonlinear waves (such as solitary waves), nonlinear oscillators, classical and quantum chaos, network science (including applications to social and biological networks), billiard systems, granular materials, and nonlinear optics. It is also important that he is a diehard fan of the Los Angeles Dodgers (a baseball team).