Research Highlights

Eccentric binary black hole surrogate models for the gravitational waveform and remnant properties: comparable mass, nonspinning case
April 2021Black holes are fascinating objects! They become more so when two of them merge. Merging black holes radiate energy in the form of gravitational waves (GWs). GWs then propagate intergalactic distances to reach Earth. Groundbased detectors operated by the Laser Interferometer GravitationalWave Observatory (LIGO) and Virgo are capable of detecting such signals. Detection of GWs […]

Gravitational hair for extreme Kerr black holes using a GPUaccelerated mixedprecision WENO method
March 2021A breakthrough discovery was made that a special kind of black hole violates black hole uniqueness, the socalled “no hair” theorem. Specifically, a computational study of extremal black holes — holes that are “saturated” with the maximum charge or spin they can possibly carry — found that there is a quantity that […]

Orbital dynamics of binary black hole systems can be learned from gravitational wave measurements
March 2021The collision of massive compact objects, such as black holes (BHs) or neutron stars, emit an immense amount of energy in the form of gravitational waves. With the advent of advanced gravitationalwave detectors, such as the NSFfunded Laser Interferometer GravitationalWave Observatory (LIGO), we are now able to directly observe gravitational waves. Encoded in these waves […]

Summer School on Data, Dynamics, and COVID19
March 2021How did the Covid pandemic affect carbon emissions in 2020? Does having a certain blood type make one more susceptible to Covid? What is the role of the uninsured population in driving the pandemic? These and many other questions were the focus of over forty graduate students and advanced undergraduates who […]

A Deeplearning Solution for the Schrödinger Equation
February 2021Solving the electronic Schrödinger equation is at the heart of computing and understanding in detail the physical and chemical properties of molecules and materials. They are of paramount importance for developing new drug molecules, biofuels or nanomaterials. Unfortunately the Schrödinger equation can only be solved exactly for the hydrogen atom, and the cost of highly […]

Better Understanding of Betti Numbers
February 2021A simplicial complex is a set formed from points, line segments, triangles, and their higherdimensional analogs. Betti numbers classify topological spaces according to the connectivity of simplicial complexes. The kth Betti number is the rank of the kth homology group and is the maximum number of cuts that can be made before separating a surface […]

Mathematicians solve one of the mysteries of twodimensional shapes
October 2020Pure mathematicians like Daniel CristofaroGardiner thrive on the creative challenge of imagining connections between things that seem unconnected and then using these connections to puzzle out old problems. Take the simplicity conjecture, which CristofaroGardiner solved earlier this year with two of his colleagues. The conjecture emerged from the work of mathematicians who, […]

New Machine Learning Approach for MeanField Games
September 2020Mean field games are critical classes of multiagent models for efficient analysis of massive populations of interacting agents with numerous applications ranging from economics to crowd motion. Their numerical solutions typically suffer from the curse of dimensionality. Numerical methods for mean field games were usually grid based. This effectively limited them to two and three […]

Quasisymmetries for Quasiparticles
August 2020For an ordinary chemical such as water, the phase diagram shows which state the chemical likes to be in at different temperatures and pressures. Water, for example, has one liquid phase and seventeen solid phases (one of which is the cubical form that you think of as “ice”). Now, mathematicians have identified […]

The Math of Irreversibility
August 2020A relatively new branch of mathematics, called higher category theory, seeks to address a common but perplexing phenomenon in math as well as other sciences. “We’re trying to build tools that allow us to capture irreversibility,” says Ezra Getzler of Northwestern University, one of 47 mathematicians who participated in the 2020 spring program on “Higher […]