  We explore the non-linear, high-frequency, aperiodic variability properties
in the three cataclysmic variables MV Lyr, KIC 8751494 and V1504 Cyg observed
with Kepler, as well as the X-ray binary Cyg X-1 observed with RXTE. This is
done through the use of a high-order Fourier statistic called the bispectrum
and its related biphase and bicoherence, as well as the time-skewness
statistic. We show how all objects display qualitatively similar biphase
trends. In particular all biphase amplitudes are found to be smaller than
$\pi/2$, suggesting that the flux distributions for all sources are positively
skewed on all observed timescales, consistent with the log-normal distributions
expected from the fluctuating accretion disk model. We also find that for all
objects the biphases are positive at frequencies where the corresponding power
spectral densities display their high frequency break. This suggests that the
noise-like flaring observed is rising more slowly than it is falling, and thus
not time-reversible. This observation is also consistent with the fluctuating
accretion disk model. Furthermore, we observe the same qualitative biphase
trends in all four objects, where the biphases display a distinct decrease at
frequencies below the high-frequency break in their respective power spectral
densities. This behaviour can also be observed in the time-skewness of all four
objects. As far as we are aware, there is no immediate explanation for the
observed biphase decreases. The biphase decreases may thus suggest that the
fluctuating accretion disk model begins to break down at frequencies below the
high frequency break.
