The Gordian distance between two knots is the fewest number of crossing changes necessary to transform one knot into the other. Khovanov homology is a categorification of the Jones polynomial that comes equipped with several spectral sequences. In this talk, we show that the page at which some of these spectral sequences collapse gives a…
Gene expression is a biochemical process driven by the chance collisions of molecules, which can result in strong stochastic signatures and cell-to-cell variability in gene network dynamics (e.g. oscillation). Biological oscillators co-exist in the same cell and can interact directly or indirectly through shared resources. Our lab uses modeling and experiments to understand how these…
The still open topological surgery conjecture for 4-manifolds is equivalent to the statement that all good boundary links are freely slice. In this talk, I will show that every good boundary link with a pair of derivative links on a Seifert surface satisfying a homotopically trivial plus assumption is freely slice. This subsumes all previously…
This talk will be devoted to a fundamental question on the compactness of sets of solutions. The key concept in this study is the Kolmogorov epsilon-entropy which is the logarithm of the minimum number of elements in an epsilon-covering of a given (totally bounded) set. I will use this concept to provide a sharp estimate…
In this talk, we analyze nonlinear differential equations subject to generalized boundary conditions. More specifically, I will provide a framework from which we can provide conditions, which are straightforward to check, for the solvability of a large number of nonlinear scalar boundary value problems. I will begin by giving the general strategy which involves a reformulation of our…
This will be the first seminar in the SIAM Industry series, which is focused on presenting information about research opportunities in business, industry, and government jobs. Speakers will discuss their career paths and speak on projects they have worked on at their current industrial institution. The DOE Exascale Computing Project (ECP), a collaborative effort between…
Classical control theory deals with controlled ODEs and PDEs. An interesting setting, where both ODE and PDE control appear naturally, is that of multi-agent systems and crowd dynamics. Recently, control problems involving measure-valued solutions attracted a lot of attention as a tool to deal with such systems. The measure can serve as the probabilistic representation…
This seminar will be an informal panel of some of our fellow graduate students speaking on their experiences with applying to and participating in internships in business, industry, and government. This will be an opportunity for graduate students to hear testimonies about the benefits and types of problems that are addressed when doing an internship…
A Kirillov-Reshetikhin(KR) module is a certain finite dimensional U_q'(\mathfrak{g}) module that is determined by its Drinfeld polynomials. KR modules are an important class of modules for quantum groups with many applications to Mathematical physics. KR modules are conjectured to have many nice properties, one of which is the existence of a crystal basis. In this talk, we will give a…
We propose a Mixed Integer Partial Differential Equation Constrained Optimization (MIPDECO) formulation of the topological optimization for electromagnetic cloaking. Our formulation introduces binary variables to indicate the presence/absence of metamaterial at a given location within the cloaking device. The cloaking device is discretized on a 20x20 and 40x40 domain of squared material locations, and has two to…
The leading eigenvalue problems arise in many applications. When the dimension of the matrix is super huge, such as for applications in quantum many-body problems, conventional algorithms become impractical due to computational and memory complexity. In this talk, we will describe some recent works on new algorithms for the leading eigenvalue problems based on randomized and coordinate-wise methods (joint work with…
Machine learning has become widely popular in fields like computer vision, natural language processing, and speech recognition, often performing tasks better than humans. A fundamental building block of many of these algorithms is a neural network known as a multilayer perceptron. In this tutorial we will discuss how to construct these networks and how to…
Target Audience: Third, Fourth, and Fifth Years
Tensors are multiway arrays, and these occur naturally in many data analysis. Consider a series of experiments tracking multiple sensors over time, resulting in a three-way tensor of the form experiment-by-sensor-by-time. Tensor decompositions are powerful tools for data analysis that can be used for data interpretation, dimensionality reduction, outlier detection, and estimation of missing data.…
In this overview talk, I will first explain several mathematical approaches of mirror symmetry. Then I will focus on the mathematical theory of Witten's gauged linear sigma model based on the recent joint work with Gang Tian, which settles the mathematical foundation of the approach of Hori and Vafa.
The Valsalva maneuver (VM) is a quick, noninvasive, clinical procedure with a variety of uses. In particular, the VM can aid in the diagnosis of autonomic nervous system dysfunction. The VM induces changes in blood pressure, which reflexively induces a neural signaling cascade to adjust heart rate, heart contractility, peripheral vascular resistance, and venous compliance.…