University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
Phone: (519) 888-4567 ext 32215
Fax: (519) 746-8115
William L Kraushaar Professor of Astronomy & Physics,
Department of Physics
University of Wisconsin-Madison
A theoretical physicist with a specialty in plasma physics, Dr. Zweibel has a broad research program in plasma astrophysics that spans the study of the sun and stars; the formation, evolution and structure of galaxies; and the physics of galaxy clusters.
She has won the APS 2016 James Clerk Maxwell Prize for Plasma Physics, citing her “seminal research on the energetics, stability and dynamics of astrophysical plasmas, including those related to stars and galaxies, and for leadership in linking plasma and other astrophysical phenomena.”
Star formation and supermassive black hole growth in galaxies appear to be self limiting. The mechanisms for self regulation are known as feedback. Cosmic rays, the relativistic particle component in interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics (GCRH), which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed.