Power means of random variables and characterizations
of distributions via fractional calculus
Kazuki Okamura
Yoshiki Otobe
Abstract:
We investigate fractional moments and expectations of power means of
complex-valued random variables by using fractional calculus. We deal
with both negative and positive orders of the fractional derivatives.
The one-dimensional distributions are characterized in terms of the
fractional moments without any moment assumptions. We explicitly compute
the expectations of the power means for both the univariate Cauchy
distribution and the Poincaré distribution on the upper half-plane. We
show that for these distributions the expectations are invariant with
respect to the sample size and the value of the power.
2010 AMS Mathematics Subject Classification: Primary 60E10; Secondary 62E10, 26A33.
Keywords and phrases: fractional moments, power mean,
characterization of distribution, Cauchy distribution, Poincaré distribution