Noise-enhanced Parametric Resonance in Perturbed Galaxies
نویسندگان
چکیده
This paper describes how parametric resonances associated with a galactic potential subjected to relatively low amplitude, strictly periodic time-dependent perturbations can be impacted by pseudo-random variations in the pulsation frequency, modeled as coloured noise. One aim thereby is to allow for the effects of a changing oscillation frequency as the density distribution associated with a galaxy evolves during violent relaxation. Another is to mimic the possible effects of internal substructures, satellite galaxies, and or a high density environment. The principal conclusion is that allowing for a variable frequency does not vitiate the effects of parametric resonance; and that, in at least some cases, such variations can increase the overall importance of parametric resonance associated with systematic pulsations. Subject headings: galaxies: evolution – galaxies: kinematics and dynamics – galaxies:
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