Math Department
Colloquium – Xiaofeng Ren, George Washington University
Topic: Non-hexagonal lattices from a two species interacting system Abstract: A two species interacting system motivated by the density functional theory for triblock copolymers contains long range interaction that affects the two species differently. In a two species periodic assembly of discs, the two species appear alternately on a lattice. A minimal two species periodic assembly
Applied Math Seminar – Steven Wise, University of Tennessee
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Convergence Analyses of some Nonlinear Multi-Level Algorithms for Non-Quadratic Convex Optimization Problems via Space Decomposition and Subspace Correction Abstract: Nonlinear multi-level methods, such as the full approximation storage (FAS) multigrid scheme, are widely used solvers for nonlinear problems. In this presentation, a new framework to analyze FAS-type methods for convex optimization problems is developed.
Analysis Seminar – Ryan Berndt, Otterbein University
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Two-weight problem for the Fourier transform. Abstract: We examine the problem of the Fourier transform mapping one weighted Lebesgue space into another, by studying necessary conditions and sufficient conditions which expose an underlying geometry. In the necessary conditions, this geometry is connected to an old result of Mahler concerning the the measure of a
Analysis Seminar – Khalid Said, University of Alabama
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesColloquium – Mark Behrens, University of Notre Dame
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: "Current themes in the study of the homotopy groups of spheres" Abstract: I will summarize the current state of affairs of the study of the stable homotopy groups of spheres, and will describe some connections to algebraic and differential geometry.
Applied Math Seminar – Rongjie Lai, Rensselaer Polytechnic Institute
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Understanding Manifold-structured Data via Geometric Modeling and Learning Abstract: Analyzing and inferring the underlying global intrinsic structures of data from its local information are critical in many fields. In practice, coherent structures of data allow us to model data as low dimensional manifolds, represented as point clouds, in a possible high dimensional space. Different
Applied Math Seminar – Trang Dinh, University of Alabama
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Understanding Tensor and Tensor Decompositions Abstract: Tensors are multidimensional arrays that can play a key role in the representation of big data. Decompositions of higher-order tensors have applications in biochemistry, signal processing, data mining, neuroscience, and elsewhere. The talk will present commonly used tensor operations and different types of tensor decomposition. Specifically, it will
Colloquium – Xiaofan Li, Illinois Institute of Technology
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Numerical simulations of macroscopic quantities for stochastic differential equations with alpha-stable processes Abstract: The mean first exit time, escape probability and transitional probability density are utilized to quantify dynamical behaviors of stochastic differential equations with non-Gaussian, $\alpha$-stable type L\'evy motions. Taking advantage of the Toeplitz matrix structure of the time-space discretization, a fast and
Applied Math Seminar – Dengfeng Sun, Purdue University
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesTitle: Improving the Convergence Rate of the Distributed Gradient Descent Method Abstract: This talk presents our recent work on the accelerated Distributed Gradient Descent (DGD) method for distributed optimization problems. We observed that the inexact convergence of the DGD algorithm can be caused by the inaccuracy in the consensus procedure in a distributed optimization setting.
Analysis Seminar – Khalid Said, University of Alabama
346 Gordon Palmer Hall 505 Hackberry Lane, Tuscaloosa, AL, United StatesAbstract In this presentation we examine some useful properties of the numerical range. We explore two dierent positions , generic and generalized generic positions. We show that two pairs of subspaces (M,N) and (M?;N?) are unitarily equivalent if M and N are subspaces of Cn in generic position by constructing a unitary operator. We establish