Oct 28 2019

### Sparse matrices in sparse analysis

Speaker: Anna Gilbert

2:00pm | Simonyi Hall 101
In this talk, I will give two vignettes on the theme of sparse matrices in sparse analysis. The first vignette covers work from compressive sensing in which we want to design sparse matrices (i.e., matrices with few non-zero entries) that we use to (linearly) sense or...

Oct 21 2019

### tba Length and volume in symplectic geometry

Speaker: Daniel Cristofaro-Gardiner

2:00pm | Simonyi Hall 101
Symplectic capacities are measurements of symplectic size. They are often defined as the lengths of certain periodic trajectories of dynamical systems, and so they connect symplectic embedding problems with dynamics. I will explain joint work showing how to recover the...

Oct 14 2019

### Finding structure in high dimensional data, methods and fundamental limitations

Speaker: Boaz Nadler

2:00pm | Simonyi Hall 101
A fundamental task in (unsupervised) analysis of data is to detect and estimate interesting "structure" hidden in it. In low dimensions, this task has been explored for over 100 years with dozens of developed methods. In this talk I'll focus on aspects of this problem for...

Oct 07 2019

### Logarithmic concavity of Schur polynomials

Speaker: June Huh

2:00pm | Simonyi Hall 101
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...

Apr 15 2019

### Etale and crystalline companions

Speaker: Kiran Kedlaya

2:00pm | Simonyi Hall 101
Deligne's "Weil II" paper includes a far-reaching conjecture to the effect that for a smooth variety on a finite field of characteristic p, for any prime l distinct from p, l-adic representations of the etale fundamental group do not occur in isolation: they always exist in...

Apr 01 2019

### A recent perspective on invariant theory

Speaker: Viswambhara Makam

2:00pm | Simonyi Hall 101
Invariant theory is a fundamental subject in mathematics, and is potentially applicable whenever there is symmetry at hand (group actions). In recent years, new problems and conjectures inspired by complexity have come to light. In this talk, I will describe some of these...