Special Colloquium
Speaker: Prof. Remco van der Hofstad, Department of Mathematics and Computer Science, Eindhoven University of Technology
Host: Ayan Bhattacharya
Title: Surprises in percolation on random graphs
Time, day and date: 2:30:00 PM - 3:30:00 PM, Wednesday, November 26
Venue: Ramanujan Hall (
Abstract: Percolation is a model for random damage to a network. It is one of the simplest models that displays a phase transition: when the network is severely damaged, it falls apart in many small connected components, while if the damage is light, connectivity is hardly affected. We study the location and nature of the phase transition on random graphs. In particular, we focus on the connectivity structure close to, or below, criticality, where components display intricate scaling behaviour such that a typical connected component has a bounded size, while the maximal connected component sizes grow like powers of the network size.
We review the recent progress that has been made on percolation on random graphs whose expected adjacency matrix is close to being rank-1, the most prominent examples being the configuration model and rank-1 inhomogeneous random graphs. Time permitting, I will also discuss the surprising phase transition on dynamic random graphs, i.e., random graphs that grow with time, such as uniform attachment models. Remarkably, these two settings behave rather differently. In all cases, the inhomogeneity of the underlying random graph on which we perform percolation is of crucial importance.
In my presentation, I focus on the surprising behaviour of percolation on random graphs with infinite-variance degrees, and on growing random graphs.
[This is joint work with Sayan Banerjee, Shankar Bhamidi, Souvik Dhara, Rajat Hazra, Johan van Leeuwaarden, and Rounak Ray.]