LSU
Mathematics

Calendar

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Tomorrow, Monday, October 14, 2019

Posted October 2, 2019

3:30 pm - 4:30 pm Lockett 233

Phuc Nguyen, Department of Mathematics, Louisiana State University
Weighted and pointwise bounds in measure datum problems with applications

Muckenhoupt-Wheeden type bounds and pointwise bounds by Wolff's potentials are obtained for gradients of solutions to a class of quasilinear elliptic equations with measure data. Such results are obtained globally over sufficiently flat domains in the sense of Reifenberg. The principal operator here is modeled after the $p$-Laplacian, where for the first time a singular case is considered. As an application, sharp existence and removable singularity results are obtained for a class of quasilinear Riccati type equations having a gradient source term with linear or super-linear power growth. This talk is based on joint work with Quoc-Hung Nguyen.

Posted September 4, 2019

3:30 pm - 4:30 pm Lockett 233

Phuc Nguyen, Department of Mathematics, Louisiana State University
TBA

Posted October 11, 2019

3:30 pm Lockett Hall 237

Tara Fife, Louisiana State University
Laminar Matroids and their Generalizations

Abstract: I''ll begin by introducing matroids, nested matroids, and laminar matroids. One characterization of laminar matroids is that for all circuits $C_1cap C_2not=emptyset$, either $C_1$ is in the closure of $C_2$ or $C_2$ is in the closure of $C_1$. We use this characterization to define two infinite families of generalized laminar matroids and give structural results of these classes. This is joint work with James Oxley.

Tuesday, October 15, 2019

Posted October 8, 2019

3:30 pm - 4:30 pm 1034 Digital Media Center

Hongchao Zhang, Louisiana State University
A Nonmonotone Smoothing Newton Algorithm for Weighted Complementarity Problem

Abstract: The weighted complementarity problem, often denoted by WCP, significantly extends the general complementarity problem and can be used for modeling a larger class of problems from science and engineering. In this talk, by introducing a one-parametric class of smoothing functions, we will introduce a smoothing Newton algorithm with nonmonotone line search to solve WCP. We will discuss the global convergence as well as local superlinear or quadratic convergence of this algorithm under assumptions weaker than assuming the nonsingularity of the Jacobian. Some promising numerical results will be also reported.

Wednesday, October 16, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

Amit Kumar, Louisiana State University
TBD

Wednesday, October 23, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

Rima Chatterjee, Louisiana State University
TBD

Posted September 11, 2019

3:30 pm - 4:30 pm Lockett 233

Hung Cong Tran, University of Oklahoma
TBD

Tuesday, October 29, 2019

Posted August 19, 2019

3:10 pm - 4:00 pm 285 Lockett

Changningphaabi Namoijam, Texas A&M
Transcendence of Hyperderivatives of Logarithms and Quasi-logarithms of Drinfeld Modules

In 2012, Chang and Papanikolas proved the transcendence of certain logarithms and quasi-logarithms of Drinfeld Modules. We extend this result to transcendence of hyperderivatives of these logarithms and quasi-logarithms. To do this, we construct a suitable t-motive and then use Papanikolas' results on transcendence degree of the period matrix of a t-motive and dimension of its Galois group.

Posted September 13, 2019

3:30 pm - 4:20 pm TBD

Marta Lewicka, University of Pittsburgh
TBD

Wednesday, October 30, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

Nurdin Takenov, Louisiana State University
TBD

Posted September 9, 2019

3:30 pm - 4:30 pm Lockett 233

Viet Dung Nguyen, Vietnam Academy of Science and Technology Institute of Mathematics
TBD

Thursday, October 31, 2019

Posted September 13, 2019

3:30 pm - 4:20 pm TBD

Selim Esedoglu , University of Michigan
TBD

Tuesday, November 5, 2019

Posted September 9, 2019

3:30 pm - 4:30 pm 1034 Digital Media Center

Jose Garay, Louisiana State University
Localized Orthogonal Decomposition Method with Additive Schwarz for the Solution of Multiscale Elliptic Problems

Abstract: The solution of elliptic Partial Differential Equations (PDEs) with multiscale diffusion coefficients using regular Finite Element methods (FEM) typically requires a very fine mesh to resolve the small scales, which might be unfeasible. The use of generalized finite elements such as in the method of Localized Orthogonal Decomposition (LOD) requires a coarser mesh to obtain an approximation of the solution with similar accuracy. We present a solver for multiscale elliptic PDEs based on a variant of the LOD method. The resulting multiscale linear system is solved by using a two-level additive Schwarz preconditioner. We provide an analysis of the condition number of the preconditioned system as well as the numerical results which validate our theoretical results.

Wednesday, November 6, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

Rob Quarles, Louisiana State University
TBD

Posted August 9, 2019

3:30 pm - 4:20 pm TBA

Dejan Slepcev, Carnegie Mellon University
TBA

Posted September 16, 2019

3:30 pm - 4:30 pm Lockett 233

Jason Behrstock, CUNY Graduate Center and Lehman College
TBD

Monday, November 11, 2019

Posted October 5, 2019

3:30 pm - 4:30 pm Lockett Room 233

Matthias Maier, Department of Mathematics Texas A&M University
TBA

Wednesday, November 13, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

Abel Lopez, Louisiana State University
TBD

Thursday, November 14, 2019

Posted September 24, 2019

3:30 pm - 4:20 pm TBD

John Voight, Dartmouth College
TBD

Tuesday, November 19, 2019

Posted October 11, 2019

3:10 pm - 4:00 pm 285 Lockett

Ignacio Nahuel Zurrian, Universidad Nacional de Cordoba (National University of Cordoba)
TBA

Posted September 9, 2019

3:30 pm - 4:30 pm 1034 Digital Media Center

Yakui Huang, Hebei University of Technology
On the Asymptotic Convergence and Acceleration of Gradient Methods

Abstract: We consider the asymptotic behavior of a family of gradient methods, which include the steepest descent and minimal gradient methods as special instances. It is proved that each method in the family will asymptotically zigzag between two directions. Asymptotic convergence results of the objective value, gradient norm, and stepsize are presented as well. To accelerate the family of gradient methods, we further exploit spectral properties of stepsizes to break the zigzagging pattern. In particular, a new stepsize is derived by imposing finite termination on minimizing two dimensional strictly convex quadratic function. It is shown that, for the general quadratic function, the proposed stepsize asymptotically converges to the reciprocal of the largest eigenvalue of the Hessian. Furthermore, based on this spectral property, we propose a periodic gradient method by incorporating the Barzilai-Borwein method. Numerical comparisons with some recent successful gradient methods show that our new method is very promising.

Wednesday, November 20, 2019

Posted September 11, 2019

1:30 pm - 3:00 pm Lockett 233

John Lien, Louisiana State University
TBD

Posted August 16, 2019

3:30 pm - 4:20 pm

Tao Mei, Balyor University
TBA

Thursday, November 21, 2019

Posted September 10, 2019

3:30 pm - 4:20 pm TBD

Leonid Berlyand, Department of Mathematics, Penn State University
TBD

Monday, November 25, 2019

Posted September 6, 2019

3:30 pm - 4:30 pm Lockett 233

Isaac Michael, Louisiana State University
TBA

Tuesday, December 3, 2019

Posted October 11, 2019

3:10 pm - 4:00 pm 285 Lockett

Kent Vashaw, Louisiana State University
TBA

Thursday, December 5, 2019

Posted September 13, 2019

3:30 pm - 4:20 pm TBD

Eric Rowell, Texas A&M
TBD