Past Events

Let G be a split reductive group. For X a projective G-homogeneous variety, there is a description of the decomposition of the Chow motive of X (Chernousov-Gille-Merkurjev, Brosnan). It is also known that these varieties satisfy the so-called Rost...

Not all quadratic equations admit solutions over the real numbers: You need to adjoin a square root of -1. Quite remarkably, once you do this, then *every* polynomial has a solution. I will explain a sense in which the category Vec_C also does not...

In this talk I'll give an overview of the mathematical side of the last eight years of my career as a software engineer at Google. This splits into two parts: writing software to automate the planning and management of Google's data centers as part...

In this talk, I will describe three projects designed to support students’ development as mathematical thinkers, with a focus on their engagement with mathematics. First, I will discuss the co-creation of ‘Student Perspective’ course materials for...

In this talk, we present two algorithms associated with Tucker tensor format. The first is to obtain the Tucker tensor based on a new cross approximation we developed, called Cross^2-DEIM. This method samples a few fibers (proportionate to the multi...

Let A ∈ M_n be nonnegative, irreducible and E_ii = e_ie_i^T, where e_i is the ith standard basis vector. For a fixed t_0 > 0, an index p ∈ [n] := {1, 2, \ldots, n} is called a winner for the value t_0 if the spectral radius satisfies \rho( A + t_0 E...

We continue last week’s talk by introducing two more combinatorial structures: simplicial and cubical complexes, which we’ll introduce and present some examples and constructions that arise from them. These complexes let us construct a family of...

In his 2005 PhD thesis on tropical linear spaces, Speyer conjectured an upper bound on the number of interior faces in a matroid base polytope subdivision of a hypersimplex. This conjecture can be reduced to determining the sign of the Euler...

In this talk, we will: 1. Introduce the most basic concepts in quantum computing. 2. Briefly highlight examples of quantum algorithms where the skills of a numerical analyst can be of use. 3. Describe one type of quantum computing hardware (a...

Defined as the difference between its two largest eigenvalues, the spectral gap of a graph plays an important role on our understanding of its connectivity as observed by Godsil and Royle (2001). Since computing the largest eigenvalue of a graph is...