Applied Maths Seminar: Zehmakan -- Information and opinion diffusion on networks: fundamentals, optimisation, and links to GNNs

Ahad Zehmakan (ANU) will give a talk on Wednesday 22 October at 1pm in Carslaw 275.  We
will go to lunch leaving Carslaw at 12.05 sharp beforehand (free for students).  

Title: Information and opinion diffusion on networks: fundamentals, optimisation, and
links to GNNs 

Abstract: In this talk, I explore models of information propagation and opinion
diffusion over networks, such as the Independent Cascade and Friedkin–Johnsen models,
where nodes iteratively update their states through interactions with their neighbours.
I first discuss the fundamental behaviour of these dynamics, for example, how properties
of the underlying graph influence the patterns, speed, and eventual equilibrium of
spreading.  Next, I discuss optimisation problems built on these dynamics, particularly
influence maximisation, which asks: given a budget for “seeding” nodes, how can we
choose them to maximise eventual spread? I highlight key algorithmic approaches and
hardness results.  Finally, I present an emerging and nuanced connection between opinion
dynamics and graph neural networks (GNNs), showing how insights from the former can
inform the design, interpretability, and robustness of the latter.