## Seminars

## Computational Math Seminar - Xiangxiong Zhang

Oct. 10, 2019

Xiangxiong Zhang, Department of Mathematics, Purdue University Monotonicity in high order accurate schemes for diffusion operators with applications to compressible Navier-Stokes equations For gas dynamics equations such as compressible Euler and Navier-Stokes equations, preserving the positivity of density and pressure without losing conservation is crucial to stabilize the numerical computation...

## Math Bio Seminar - Sabina Altus

Oct. 8, 2019

Sabina Altus, Department of Applied Mathematics, University of Colorado Boulder Multi-Structured Population Dynamics in Cyanobacteria Cyanobacteria are photosynthetic microorganisms with promising applications in renewable energy and agriculture as they are able to convert light energy into more stable forms of chemical energy, such as biomass, as well as kinetic energy...

## Nonlinear Waves Seminar - Patrick Weidman

Oct. 8, 2019

Patrick Weidman Department of Mechanical Engineering, University of Colorado Boulder Steady flow of one uniformly rotating fluid layer above another immiscible uniformly rotating fluid layer. The steady laminar flow of two immiscible, uniformly rotating fluid layers is studied and exact similarity solutions of the axisymmetric Navier-Stokes equations in cylindrical polar...

## Applied Math Colloquium - Andreas Kloeckner

Oct. 4, 2019

Andreas Kloeckner Department of Computer Science, University of Illinois Fast Algorithms for the Evaluation of Layer and Volume Potentials I will present new, asymptotically fast algorithms with high-order error bounds for the evaluation of layer and volume potentials in two and three dimensions. The efficient evaluation of both types of...

## Postdoc Tutorial: LaTeX Documents and Presentations

Oct. 4, 2019

The Postdoctoral Association of Colorado, Boulder has organized this series of monthly tutorials/workshops on topics that may be useful to postdocs, students, and faculties across different disciplines. Everyone is invited to attend! If you'd like to offer to give one workshop, and/or have topic ideas, please fill out this form...

## Complex/Dynamical Systems Seminar - Bernd Kraukopf and Hinka Osinga

Oct. 3, 2019

Bernd Krauskopf and Hinka Osinga Department of Mathematics, University of Auckland Hetero-dimensional Cycles and Blenders Recent theoretical work on partially hyperbolic systems by Bonatti and Diaz (and others) has shown that chaotic dynamics may occur C1-robustly in diffeomorphisms of dimension at least three. More specifically, the existence of hetero-dimensional cycles...

## Math Bio Seminar - Erin Ellefsen

Oct. 1, 2019

Erin Ellefsen Department of Applied Mathematics University of Colorado Boulder Efficiently finding steady states of nonlocal territorial models in Ecology There are certain populations of animals that tend to move in social groups. We investigate territory development of these social groups by studying a system of non-local continuum equations. However,...

## Stats, Optimization, and Machine Learning Seminar - Yury Makarychev

Oct. 1, 2019

Yury Makarychev Toyota Technological Institute at Chicago (TTIC) Performance of Johnson-Lindenstrauss Transform for k-Means and k-Medians Clustering Consider an instance of Euclidean k-means or k-medians clustering. We show that the cost of the optimal solution is preserved up to a factor of (1+ε) under a projection onto a random O(log(k/ε)/ε^2)-dimensional...

## Applied Math Colloquium - Rebecca Morrison

Sept. 27, 2019

Rebecca Morrison Department of Computer Science, University of Colorado Boulder Representing model error in reduced models of interacting systems In many applications of interacting systems, we are only interested in the dynamic behavior of a subset of all possible active species. For example, this is true in combustion models (many...

## Joint APPM/MATH Colloquium - Catherine Sulem

Sept. 24, 2019

Catherine Sulem Department of Mathematics, University of Toronto Bloch theory and spectral gaps for linearized water waves We consider the movement of a free surface of a two-dimensional fluid over a variable bottom. We assume that the bottom has a periodic prole and we study the water wave system linearized...