Frontiers of Invariant Manifold Approximation in Multiple-Timescale Dynamics

Ian Lizarraga from the School of Mathematics and Statistics, The University of Sydney, (ian.lizarraga (at) sydney.edu.au) describes how to use the computational singular perturbation (CSP) method and the parametrization method to compute approximations to invariant manifolds. He also shows how the parametrization method can be adapted to problems with more than two time scales.

A Mathematical Approach to Defensive Positioning in Baseball

Elizabeth Bouzarth, Benjamin Grannan, John Harris, Andrew Hartley, Kevin Hutson, and Ella Morton describe a model using batter-specific refinements to optimize the locations of the fielders in baseball.

The Cauchy-Schwarz Inequality via Springs

Mark Levi describes a physical model of the Cauchy-Schwartz inequality.

Questions of Responsibility: Modelling in the Age of COVID-19

Maurice Chiodo and Dennis Müller discuss ethical questions that arise in math research with a special focus on COVID-19.

Data Assimilation in Medicine

David Albers, Cecilia Diniz Behn, and George Hripcsak write about using ODE models of physiology to make forecasts with sparse, inaccurate data.