Graphs

Ramon van Handel surveys recent progress on constructing graphs, manifolds and groups with optimal spectral gaps, which control how rapidly random walks explore a structure. The talk describes a polynomial method that proves optimality in new settings and connects these developments to longstanding questions about the prevalence of optimal gaps.

This talk introduces non-negative Ollivier–Ricci curvature on graphs and examines what it implies for the large-scale geometry of bounded-degree networks. It presents recent results developed jointly with Camillo Brena and Florentin Munch without assuming prior familiarity with this curvature notion.

…and why extremal questions about graphs are mathematically productive. The interview follows recognition of his work with an EMS Prize.

…is often conveyed through figures, graphs, and diagrams (Mayer, 1993). Comparing within and across visuals is critical for gleaning insight into the underlying concepts, structures, and processes that they represent. This talk addresses how people make visual comparisons and how visual comparisons can be best supported to improve learning. In particular, the talk will present a series of s