Events

Title: Resilience of the rank of random matrices

Abstract:

I will discuss the preprint of this title by Ferber, Luh, and McKinley (arXiv:1910.03619).

Title: Incompressibility of classical distributions

Abstract:

We prove a general, robust, single-letter lower bound on the achievable rate for ensembles of classical states, which holds even when Alice and Bob share free entanglement and allow a constant local error. 

Title: How can we optimize nonsmooth objectives globally?

Abstract:

In machine learning objective functions that are only piecewise smooth and should be globally minimized abound. The standard method of dealing with them is to apply a stochastic gradient method disregarding the rare points of nonsmoothness and hoping for the best as far as global optimality of the computed solution is concerned.

Title: Inverses of Trees

Abstract:

A tree is invertible if and only if it has a perfect matching.

Godsil considers an invertible tree T and finds that the inverse of the adjacency matrix has entries in {0, ±1} and is the signed adjacency matrix of a graph which contains T.

Title: Biometric security: Design, implementation, and challenges

Abstract:

Biometric based cybersecurity technologies offer significant advantages in authentication, identification, and access control mechanisms.

Title: Graph covers with two new eigenvalues

Abstract:

I am going to talk about graph covers. If $Y$ is a cyclic cover of $X$, it turns out that $Y$ has the same spectrum as $X$ plus (possibly) some new eigenvalues. 

Title: OutFn, M_gn and renormalized topological field theory

Abstract:

I will report on recent joint work with Karen Vogtmann on the Euler characteristic of Out(F_n) and the moduli space of graphs.

Title: Periodicity in Quantum Walks

Abstract:

Despite the title, quantum walks are, in general, not periodic. However they are, in general, periodic to any desired degree of accuracy.

Title: Beating 3/2 for Approximating TSP in the Half-Integral Case

Abstract:

In 2013, Schalekamp, Williamson, and van Zuylen conjectured that the integrality gap for the Subtour Polytope was attained on its half-integral vertices.

Title: Covers of Complete Bipartite Graphs

Abstract:

I will discuss antipodal distance-regular covers of complete bipartite graphs $K_{n,n}$. The index of such a cover is at most $n$.