3 papers
astro-ph.GA2026
Cold kinetic theory is not cold fluid theory: A collective mode in self-gravitating spheres
Mikael Tacu
Cold collisionless matter is usually described by pressureless fluid equations; this fails in three-dimensional spherical geometry. For the cold spherical case, kinetic and fluid d…
physics.plasm-ph2025
Imaginary part of the conductivity using Kramers-Kronig relations
Jean-Christophe Pain, Mikael Tacu
In order to obtain the frequency-dependent photo-absorption in a plasma, both the real and imaginary parts of the AC conductivity are required. The real part can be deduced from th…
physics.plasm-ph2025
Why Cold BGK Modes Are So Cool: Dispersion Relations from Orbit-Constrained Distribution Functions
Mikael Tacu
We derive analytic dispersion relations for cold, orbitally constrained systems governed by the Vlasov equation. For magnetized plasmas, we obtain the first explicit relation for t…