Abstract: Radiative plasma processes in neutron star and white dwarf magnetospheres play a central role in shaping their radio emission and high-energy variability. Magnetospheric gaps 鈥� regions of unscreened electric field 鈥� are natural sites of extreme particle acceleration, radiation, and electron鈥損ositron pair creation. They are thought to trigger pair cascades and regulate magnetospheric activity in radio pulsars, millisecond pulsars, and possibly the white-dwarf-hosting long-period transients.Their time-dependent plasma physics, however, remains poorly understood.
In this talk I will present our recent work on the radiative plasma physics of these discharges. We develop an analytical theory for the coupled evolution of electric field, particle acceleration, radiation, and pair creation in this extreme regime, and complement it with first-principles radiative particle-in-cell simulations that include exact QED processes and realistic plasma parameters, allowing us to test and validate the theoretical predictions.