Article
Keywords:
characterizations; Gamma distribution
Summary:
In this paper we derive conditions upon the nonnegative random variable \xi under which the inequality $Dg(\xi)\leq cE\left[g'\left(\xi\right)\right]^2\xi$ holds for a fixed nonnegative constant $c$ and for any absolutely continuous function $g$. Taking into account the characterization of a Gamma distribution we consider the functional $U_\xi = \sup_g \frac{Dg\left(\xi\right)}{E\left[g'\left(\xi\right)\right]^2\xi}$ and establishing some of its properties we show that $U_\xi \geq 1$ and that $U_\xi =1$ iff the random variable $\xi$ has a Gamma distribution.
References:
[2] A. A. Borovkov S. A. Utev:
On an inequality and a related characterization of the normal distribution. Theory of Probab. and its Appl. 28 (2) (1983), 219-228.
MR 0700206