School of Mathematics

Existence of infinitely many minimal hypersurfaces in closed manifolds

Antoine Song
Princeton University
October 23, 2018
In the early 80’s, Yau conjectured that in any closed 3-manifold there should be infinitely many minimal surfaces. I will review previous contributions to the question and present a proof of the conjecture, which builds on min-max methods developed by F. C. Marques and A. Neves. A key step is the construction by min-max theory of a sequence of closed minimal surfaces in a manifold N with non-empty stable boundary, and I will explain how to achieve this via the construction of a non-compact cylindrical manifold.

Small-Set Expansion on the Grassmann Graph.

Dor Minzer
Member, School of Mathematics
October 23, 2018
A graph G is called a small set expander if any small set of vertices contains only a small fraction of the edges adjacent to it.
This talk is mainly concerned with the investigation of small set expansion on the Grassmann Graphs, a study that was motivated by recent applications to Probabilistically Checkable Proofs and hardness of approximation.

Approximating the edit distance to within a constant factor in truly subquadratic time.

Mike Saks
Rutgers University
October 22, 2018
Edit distance is a widely used measure of similarity of two strings based on the minimum number of character insertions, deletions, and substitutions required to transform one string into the other. The edit distance can be computed exactly using a classical dynamic programming algorithm that runs in quadratic time.

New and old results in the classical theory of minimal and constant mean curvature surfaces in Euclidean 3-space R^3

Bill Meeks
University of Massachusetts Amherst
October 22, 2018
In this talk I will present a survey of some of the famous results and examples in the classical theory of minimal and constant mean curvature surfaces in R^3. The first examples of minimal surfaces were found by Euler (catenoid) around 1741, Muesner (helicoid) around 1746 and Riemann (Riemann minimal examples) around 1860. The classical examples of non-zero constant mean curvature surfaces are the Delaunay surfaces of revolution found in 1841, which include round spheres and cylinders.

Asymptotic spectra and their applications II

Jeroen Zuiddam
Member, School of Mathematics
October 16, 2018
These two talks will introduce the asymptotic rank and asymptotic subrank of tensors and graphs - notions that are key to understanding basic questions in several fields including algebraic complexity theory, information theory and combinatorics.

Matrix rank is well-known to be multiplicative under the Kronecker product, additive under the direct sum, normalized on identity matrices and non-increasing under multiplying from the left and from the right by any matrices. In fact, matrix rank is the only real matrix parameter with these four properties.