Fluctuations due to a super-position of uncorrelated Lorentzian pulses with a
random distribution of amplitudes and duration times are considered. These are
demonstrated to be strongly intermittent in the limit of weak pulse overlap,
resulting in large skewness and flatness moments. The characteristic function
and the lowest order moments are derived, revealing a parabolic relationship
between the skewness and flatness moments. Numerical integration reveals the
probability density functions in the case of exponential and Laplace
distributed pulse amplitudes. This stochastic model describes the intermittent
fluctuations and probability densities with exponential tails commonly observed
in turbulent fluids and magnetized plasmas.Comment: 12 pages, 3 figure