On the time variability of geometrically-thin black hole accretion disks I : the search for modes in simulated disks

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We present a detailed temporal analysis of a set of hydrodynamic and magnetohydrodynamic (MHD) simulations of geometrically-thin (h/r~0.05) black hole accretion disks.

• The black hole potential is approximated by the Paczynski-Wiita pseudo-Newtonian potential.
• In particular, we use our simulations to critically assess two widely discussed models for high-frequency quasi-periodic oscillations, global oscillation modes (diskoseismology) and parametric resonance instabilities.
• We find that initially disturbed hydrodynamic disks clearly display the trapped global g-mode oscillation predicted by linear perturbation theory.