  We present a broad-band timing analysis of the accreting white dwarf system
MV Lyrae based on data obtained with the Kepler satellite. The observations
span 633 days at a cadence of 58.8 seconds and allow us to probe 4 orders of
magnitude in temporal frequency. The modelling of the observed broad-band noise
components is based on the superposition of multiple Lorentzian components,
similar to the empirical modelling adopted for X-ray binary systems. We also
present the detection of a frequency varying Lorentzian component in the
lightcurve of MV Lyrae, where the Lorentzian characteristic frequency is
inversely correlated with the mean source flux. Because in the literature
similar broad-band noise components have been associated to either the viscous
or dynamical timescale for different source types (accreting black holes or
neutron stars), we here systematically explore both scenarios and place
constraints on the accretion disk structure. In the viscous case we employ the
fluctuating accretion disk model to infer parameters for the viscosity and disk
scale height, and infer uncomfortably high parameters to be accommodated by the
standard thin disk, whilst in the dynamical case we infer a large accretion
disk truncation radius of ~10 white dwarf radii. More importantly however, the
phenomenological properties between the broad-band variability observed here
and in X-ray binaries and Active Galactic Nuclei are very similar, potentially
suggesting a common origin for the broad-band variability.
