This is the list of Colloquium talks that are given in the department.

| Novel Perspectives in Understanding the Geometry of Surfaces and ManifoldsHung Tran Department of Mathematics and Statistics, Texas Tech University |

The second theme is the search for a hierarchy of stationary surfaces, which are critical points of a certain geometric functional. In Calculus, we use derivative tests to classify critical points and determine whether one is a minimum, a maximum, or a saddle. An abstract generalization is to study the index of an operator associated with the second variation. In this direction, we develop a novel mechanism, via partial differential equations when studying surfaces with boundaries, with several applications. Specifically, there is a partial resolution of a conjecture proposed by R. Schoen and A. Fraser and closely related to the Willmore conjecture. Another significant contribution is to introduce a new approach based on functional analysis to investigate a setup with constraints.

Dr. Hung Tran's Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| Conservative Low-Rank Approximations to Nonlinear Vlasov DynamicsWei Guo Department of Mathematics and Statistics, Texas Tech University |

Dr. Wei Guo's Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| Studying Recurrent Diseases and Multiple Disease Outcomes via Applied Bifurcation TheoryWenjing Zhang Department of Mathematics and Statistics, Texas Tech University |

Dr. Wenjing Zhang's Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| Topics in scientific computing: applications, uncertainty, and algorithmsKatharine Long Department of Mathematics and Statistics, Texas Tech University |

Dr. Katharine Long's Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| A Time Scales Approach to ModelingRaegan Higgins Department of Mathematics and Statistics, Texas Tech University |

A few years ago, I changed the direction of my research, focusing on more applied problems instead of theoretical ones. Of particular interest are issues arising in mathematical biology. While infusing an introduction to the time scales theory, in this talk, we use dynamic equations on time scales to model intermittent androgen deprivation (IAD) therapy. Our approach is novel since time scales combine continuous and discrete time and have not been used to model IAD therapy. Traditionally, continuous ordinary differential equations are used to estimate prostate-specific antigen levels, which are used to determine the timing of a pause in IAD treatment. In this work, we use dynamic equations to estimate prostate-specific antigen levels and construct a time scale model to account for continuous and discrete time simultaneously. We discuss preliminary results on the development of specific models and present the next steps.

We conclude the talk with activities related to my service mission.

Dr. Raegan Higgins' Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| Numerical Linear Algebra in Scientific Computing and Machine Learning AlgorithmsVictoria Howle Department of Mathematics and Statistics, Texas Tech University |

In addition, I will briefly describe two other projects. One is using machine learning algorithms to improve preconditioners, and the other is in simulation and machine learning for classification of skeletal trauma.

Dr. Victoria Howle's Tenure and Promotion Colloquium has been archived in the Mediasite catalog.

| Lack of Fredholm solvability for the Dirichlet problem for general weakly elliptic systemsDorina Mitrea Department of Mathematics, Baylor University |

| Integrability and control of figure skatingVakhtang Poutkaradze Department of Mathematics and Statistics, University of Alberta |

Slideshow pdf available

| Invariant-domain preserving high-order implicit explicit time stepping for nonlinear conservation equationsJean-Luc Guermond Department of Mathematics, Texas A&M University |

This Departmental Colloquium is sponsored by the

Meeting ID: 976 3095 1027

Passcode: applied

| SIAM & AWM Research ColloquiumSix Texas Tech Assistant Professors Department of Mathematics and Statistics, Texas Tech University |

Dr. Alvaro Pampano Some Geometric Variational Open Problems

Dr. Juntao Huang Structure-Preserving Machine Learning Moment Closures for the Radiative Transfer Equation

Dr. Suddhasattwa Das Learning Theory for Dynamical Systems

Dr. Travis Thompson Mathematics makes a difference: Modeling, Analysis, Computing, and Frontier of Brain Research

Dr. Hongwei Mei Stochastic Systems, Control and Optimization, and Optimal Stopping

Dr. Ignacio Tomas Energy Stability of Diagonally Implicit Runge-Kutta Methods

This Departmental Colloquium was sponsored by the TTU chapters of

| Kinetic models of particle systemsCory Hauck Computer Science and Mathematics Division, Oak Ridge National Laboratory |