I am Matthieu Latapy, a CNRS senior researcher, member of the Complex Networks team at LIP6 (CNRS and Sorbonne University), Paris, France.
I am involved in FJN, SU CER, SIF, Ecopolien, Sciences Citoyennes, MSER, Labo1.5, SR, and others.
See my CV (pdf) for more information.
I work on network science and its applications, in particular:
A link stream basically is a sequence of triplets of the form (t,u,v) meaning that an interaction occurred at time t between u and v. This models a wide variety of important data, like contacts between individuals, money transfers, network traffic, message passing, etc.
(I claim that) graphs and time series may be seen as particular link streams. As a consequence, graph theory and signal processing concepts may be generalized and unified into a theory of link streams themselves. For instance, one may define the density of a link stream, or cliques in link streams, see my paper generalizing graph concepts to link streams.
Money laundary and frauds cost billions every year, estimated close to 2% of the whole world GDP. This money fuels corruption and terrorism at internaional level, with critial consequences on human activities. Therefore, detecting and fighting them is a crucial concern.
Payment records and money transfers are best modeled as link streams, that capture both the structure and dynamics of exchanges. Then, anomalous activity leaves specific traces in these link streams. I therefore develop graph-based and link-stream-based methods to detect such traces. In particular, I run the Fit LabCom on anomaly and fraud detection in financial transactions.
Humanity faces overwhelming ecological and social challenges, like climate change, biodiversity collapse, inequality growth, or autoritarism, to cite only a few. Unsatisfactory progress on these crucial issues leads to the development of ecological and social activism beyond classical protests and petitions. In particular, several movements target infrastructure perturbation like transportation or communication networks, in a way similar to people resisting illegitimate governments or foreign military occupation.
I work on estimating the relevance of such approaches, their potential impact, as well as underlying resistance strategies. See for instance my PhD or internship proposals (in french, pdf) here, here, and here.