His main interests are plasma turbulence, the role of turbulence in the solar corona and other astrophysical settings, and the evolution of baryonic matter in clusters of galaxies. He has also worked on cosmic-ray propagation, particle acceleration at shocks, and the origin of astrophysical magnetic fields. His research program is supported by grants from NASA, NSF, and DOE, and offers research opportunities for undergraduates, graduate students, and postdoctoral scholars.