Dear all,

I am pleased to announce a seminar talk by Eviatar Procaccia at the Department of Mathematics and Applications of the University of Milano-Bicocca on Thursday, March 12 at 15:30. Below you can find the details.

Best regards,

Tal Orenshtein

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Time and place: Thursday, March 12, 2026 at 15:30, Room U9/08 (Edificio U9, viale dell'Innovazione 10)

Speaker: Eviatar Procaccia (Technion – Israel Institute of Technology)

Title: The Pool Model: a rotationally symmetric, mass-preserving MDLA variant

Abstract: Multi-particle diffusion-limited aggregation (MDLA) describes the growth of an aggregate driven by a cloud of diffusing particles. Classic works of Kesten, Rath, Sidoravicius, Stauffer, and Sly show that in the high-intensity regime the MDLA aggregate grows linearly in time, while the low-intensity regime remains largely open.

We introduce the pool model, a rotationally symmetric analogue in which particles (“droplets”) perform continuous-time random walks and are absorbed upon entering a circular pool initially centered at the origin. Each absorbed particle increases the pool’s mass, and the pool expands so that its area grows accordingly—yielding a natural mass-preserving dynamics. The imposed rotational symmetry makes the model more tractable for rigorous analysis, while retaining key features of MDLA.

In this talk we focus on the critical density separating finite growth from explosive behavior, and we present rigorous bounds on the pool’s growth rate at and near criticality.