Libby Tolman is a plasma astrophysicist and an incoming Assistant Professor in the Department of Physics and Astronomy at the University of Iowa. She is working to apply laboratory plasma physics theory to the study of astrophysical compact object emission, with the goal of enabling the use of these objects as laboratories for fundamental physics.

Astrophysical compact objects, such as neutron stars and black holes, are characterized by much stronger gravitational fields, much stronger magnetic fields, and much longer length scales than terrestrial systems, making them ideal laboratories for studying issues at the forefront of fundamental physics, including the nature of dark matter and the behavior of matter in strong gravity.  However, in many cases, the electromagnetic emission from these systems–a main tool for probing them–is not sufficiently well understood to allow this investigation to occur. This emission is produced in plasmas, which are ionized gases. Scientists who study plasmas in terrestrial labs are experts in how this state of matter behaves; Tolman is applying their knowledge to the study of these astrophysical systems.

For example, Tolman's paper, “Electric field screening in pair discharges and generation of pulsar radio emission,” studies highly relativistic pulsar polar cap discharges using methods developed to study waves and energetic particles in laboratory tokamak plasmas, yielding a potential explanation for the previously unexplained pulsar radio luminosity and spectrum.  This work has been useful for studies by other scientists that look for signs of axions, a candidate dark matter particle, in pulsar emission. 

Tolman received her undergraduate degree in 2015 from Princeton University, working with Professor Herman Verlinde, senior thesis advisor. She completed her PhD in 2020 in the MIT Department of Physics, advised by Professor Nuno Loureiro. At MIT, she was a member of the Plasma Science and Fusion Center and worked primarily on laboratory plasma physics. After completing her PhD, Tolman moved to the Institute for Advanced Study in Princeton, NJ, to begin work in theoretical plasma astrophysics. She later became a Flatiron Research Fellow at the Center for Computational Astrophysics. At the IAS and the CCA, she worked with several scientists, including Professors Stone, Kunz, and Philippov.