Alexander (Sasha) Philippov
I am an Assistant Professor in the Department of Physics at the University of Maryland, College Park. Before joining the faculty at Maryland in 2022, I spent a year as a NASA Einstein Fellow at University of California, Berkeley, and four years at the Flatiron Institute as an Associate Research Scientist. I am most excited about the theory and modeling of plasmas around black holes and neutron stars.
My research utilizes numerical simulations to understand extreme plasma physical processes, such as relativistic magnetic reconnection, plasma turbulence and pair production lightnings, operating in relativistic magnetospheres and jets, and their observed signatures. My research on pulsars described the locations of particle acceleration zones in the magnetosphere, established the role of large-scale reconnecting current sheet in powering observed gamma-rays and produced first-principles models of coherent radio emission. Recently my collaborators and I explored how current sheets can power high-energy flares in the surroundings of accreting black holes, in part using the first general-relativistic kinetic plasma code.
A recent focus of my research group has been on: (i) developing models of coherent radio emission produced during pair production lightnings and relativistic magnetic reconnection occurring in magnetospheres of neutron stars, in application to pulsars and Fast Radio Bursts; (ii) understanding mechanisms of producing electromagnetic flares in accretion flows around supermassive black holes and magnetospheres of merging neutron stars; (iii) exploring the role of kinetic plasma effects, such as the accelerated rate of magnetic reconnection, significant pressure anisotropy and heat flux, in shaping the dynamics and observational appearance of accreting plasmas around black holes in M87 and Milky Way; (iv) investigating particle acceleration in radiative plasma turbulence occurring in the magnetized coronae of black holes. I am looking forward to exciting new discoveries in this rapidly growing research field, made in collaboration with SCEECS members.
Five recent relevant references
Galishnikova A., Philippov A., Quataert E., Bacchini F., Parfrey K., Ripperda B., Collisionless Accretion onto Black Holes: Dynamics and Flares, PRL, Volume 130, Issue 11, article id.115201, 2023.
Philippov A., Timokhin A., Spitkovsky A., On the origin of pulsar radio emission, PRL, volume 124, Issue 24, 245101, 2020.
Parfrey K., Philippov A., Cerutti B., First-Principles Plasma Simulations of Black-Hole Jet Launching, PRL, volume 122, Issue 19, 035101, 2019.
Philippov A., Uzdensky D., Spitkovsky A., Cerutti B., Pulsar Radio Emission Mechanism: Radio Nanoshots as a Low Frequency Afterglow of Relativistic Magnetic Reconnection, ApJL, volume 876, Issue 1, article id. L6, 2019.
Philippov A., Spitkovsky A., Ab-Initio Pulsar Magnetosphere: Particle acceleration in Oblique Rotators and High-energy Emission Modeling, ApJ, Volume 855, Issue 2, article id. 94, 2018.