Kristen Schumacher Aloh

Gravitational Physicist

I’m an NSF ASCEND and Weinberg Institute Postdoctoral Fellow in theoretical astrophysics, jointly appointed at Caltech and UT Austin. I use gravitational waves to study modified theories of gravity, probe cosmology, and understand neutron stars.

In theories beyond general relativity, gravitational waves may contain up to six polarizations. The animation shows all six distorting a tube of test particles. See each polarization on its own.

My work spans the gravitational-wave spectrum, across ground-based detectors (LVK), future space-based detectors (LISA), and pulsar timing arrays (NANOGrav). Passionate about making astrophysics accessible, I also develop visualization tools to help both experts and non-experts understand complex concepts and to inspire curiosity about the universe.

Currently I am exploring:

potential methods to place constraints on additional polarizations of gravitational waves
gravitational waves as cosmological probes
gravitational wave constraints on the equation of state of neutron stars

Polarizations of gravitational waves

Though waves in general relativity contain only two polarizations, waves in modified theories of gravity may consist of up to six polarizations. Under my leadership the POINT collaboration developed animations which illustrate how the different polarizations of gravitational waves distort spacetime.

To use these animations in talks, please credit [Schumacher et al., ISVC 2024; POINT collaboration].

VR & visualization

Plus and cross General relativity

The two tensor polarizations present in general relativity.

All six possible Beyond general relativity

The six polarizations a generic metric theory of gravity would permit, propagating together.