Climate variability amplifies the need for vector-borne disease outbreak preparedness
Hart, W Hurrel, J Kaye, A Chand, M Keeling, M Thompson, R Proceedings of the National Academy of Sciences volume 122 issue 34 (18 Aug 2025)
A new local time-decoupled squared Wasserstein-2 method for training stochastic neural networks to reconstruct uncertain parameters in dynamical systems
Xia, M Shen, Q Maini, P Gaffney, E Mogliner, A Neural Networks (05 Aug 2025)
Mon, 13 Oct 2025
14:15
L4

Non-maximal Toledo components

Oscar Garcia-Prada
(Instituto de Ciencias Matemáticas (ICMAT))
Abstract

The well-known Milnor-Wood inequality gives a bound on the Toledo invariant of a representation of the fundamental group of a compact surface in a non-compact Lie group of Hermitian type. While a lot is known regarding the counting of maximal Toledo components, and their role in higher Teichmueller theory, the non-maximal case remains elusive. In this talk, I will present a strategy to count the number of such non-maximal Toledo connected components. This is joint work in progress with Brian Collier and Jochen Heinloth, building on previous work with Olivier Biquard, Brian Collier and Domingo Toledo.

Mon, 20 Oct 2025
14:15
L4

Einstein constants and differential topology

Claude LeBrun
(Stony Brook University)
Abstract

A Riemannian metric is said to be  Einstein if it has constant Ricci curvature. In dimensions 2 or 3, this is actually equivalent to requiring the metric to have constant sectional curvature. However,  in dimensions 4 and higher, the Einstein condition becomes significantly weaker than constant sectional curvature, and this has rather dramatic consequences. In particular, it turns out that there are  high-dimensional smooth closed manifolds that admit pairs of Einstein metrics with Ricci curvatures of opposite signs. After explaining how one constructs such examples, I will then discuss some recent results exploring the coexistence of Einstein metrics with zero and positive Ricci curvatures.

The unknotting number, hard unknot diagrams, and reinforcement learning
Lackenby, M Blackwell, S Davies, A Edlich, T Juhasz, A Tomašev, N Zhang, D Experimental Mathematics (18 Aug 2025)
From Brownian dynamics to Poisson-Nernst-Planck equations: multi-resolution simulations of ions
Zhang, J Erban, R (24 Jun 2025)
A minimax method for the spectral fractional Laplacian and related evolution problems.
Carrillo, J Fronzoni, S Nakatsukasa, Y Süli, E CoRR volume abs/2505.20560 (May 2025)
Exploring the Non-uniqueness of Node Co-occurrence Matrices of Hypergraphs.
LaRock, T Lambiotte, R (01 Jun 2025)
Mechanical stresses in pouch cells: a reduced order model
Giudici, A Please, C Chapman, J Journal of Engineering Mathematics
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