Manchester Building (Hall 2), Hebrew University Jerusalem
I will discuss some recent advances in combinatorics, among them the disproof of Hedetniemi conjecture by Shitov, the proof of the sensitivity conjecture by Huang, the progress on the Erdos-Rado sunflower conjecture by Alweiss, Lovett, Wu, and Zhang, and the progress on the expectation threshold conjecture by Frankston, Kahn, Narayanan, and Park.
Manchester Building (Hall 2), Hebrew University Jerusalem
Title: Systems of points with Coulomb interactions Abstract: Large ensembles of points with Coulomb interactions arise in various settings of condensed matter physics, classical and quantum mechanics, statistical mechanics, random matrices and even approximation theory, and they give rise to a variety of questions pertaining to analysis, Partial Differential Equations and probability.
Manchester Building (Hall 2), Hebrew University Jerusalem
Abstract: the theory of complex multiplication is more than a century old; its origins date back to Klein, Hilbert, Kummer, Weber, Deuring and many others. It has been instrumental in the development of class field theory and algebraic number theory. Yet, more than a century later we find new theorems that are truly surprising.
Manchester Building (Hall 2), Hebrew University Jerusalem
A variety of algebra is a concept like "monoid", "group" or "ring" (but not "field"), which can be axiomatized by finitary operations (e.g. multiplication, inversion) and universally quantified axioms (e.g. associativity).
Manchester Building (Hall 2), Hebrew University Jerusalem
The development of symplectic topology was motivated by Hamiltonian mechanics. It has been particularly successful in addressing one specific aspect, namely fixed points and periodic points of discrete-time Hamiltonian systems. I will explain how such applications work, both in older and more recent examples.
Manchester Building (Hall 2), Hebrew University Jerusalem
Physical systems are regularly studied as spatial point sets, and so understanding the structure in such sets is a very natural problem. However, aside from several special cases, describing the manner in which a set of points can be arranged in space has been historically challenging. In the first part of this talk, I will show how consideration of the configuration space of local arrangements of neighbors, and a few simple results in metric geometry, can shed light on essential challenges of this problem, and in the classification of data more generally.
Manchester Building (Hall 2), Hebrew University Jerusalem
Hamiltonian Floer cohomology was invented by A. Floer to prove the Arnold conjecture: a Hamiltonian diffemorphism of a closed symplectic manifold has at least as many periodic orbits as the sum of the Betti numbers. A variant called Symplectic cohomology was later defined for certain non compact manifolds, including the cotangent bundle of an arbitrary closed smooth manifold. The latter is the setting for classical mechanics of constrained systems.
Manchester Building (Hall 2), Hebrew University Jerusalem
Title: The (B)-conjecture andfunctional inequalities
Abstract:
The log-Brunn-Minkowski inequality is an open problem in convex geometry regarding the volume of convex bodies. The (B)-conjecture is an apparently different problem, originally asked by probabilists, which turned out to be intimately related the the log-Brunn-Minkowski inequality.
