Recently Added

Unsupervised Ensemble Learning

Boaz Nadler
Weizmann Institute of Science; Member, School of Mathematics
October 8, 2019

In various applications, one is given the advice or predictions of several classifiers of unknown reliability, over multiple questions or queries. This scenario is different from standard supervised learning where classifier accuracy can be assessed from available labeled training or validation data, and raises several questions: given only the predictions of several classifiers of unknown accuracies, over a large set of unlabeled test data, is it possible to

a) reliably rank them, and

Weak solutions of the Navier-Stokes equations may be smooth for a.e. time

Maria Colombo
École Polytechnique Fédérale de Lausanne; von Neumann Fellow, School of Mathematics
October 7, 2019

In a recent result, Buckmaster and Vicol proved non-uniqueness of weak solutions to the Navier-Stokes equations which have bounded kinetic energy and integrable vorticity. 

 

We discuss the existence of such solutions, which in addition are regular outside a set of times of dimension less than 1. 

Bourgeois contact structures: tightness, fillability and applications.

Agustin Moreno
University of Augsburg
October 7, 2019
Starting from a contact manifold and a supporting open book decomposition, an explicit construction by Bourgeois provides a contact structure in the product of the original manifold with the two-torus. In this talk, we will discuss recent results concerning rigidity and fillability properties of these contact manifolds. For instance, it turns out that Bourgeois contact structures are, in dimension 5, always tight, independent on the rigid/flexible classification of the original contact manifold.

Logarithmic concavity of Schur polynomials

June Huh
Visiting Professor, School of Mathematics
October 7, 2019

Schur polynomials are the characters of finite-dimensional irreducible representations of the general linear group. We will discuss both continuous and discrete concavity property of Schur polynomials. There will be one theorem and eight conjectures. No background beyond basic representation theory will be necessary to enjoy the talk. Based on joint work with Jacob Matherne, Karola Mészáros, and Avery St. Dizier.