grandes-ecoles 2017 QII.B.4

grandes-ecoles · France · centrale-maths2__mp Sum of Poisson processes
Let $r$ be a non-zero natural integer and let $X_{1}, \ldots, X_{r}$ be mutually independent Poisson random variables. Show that $\sum_{i=1}^{r} i X_{i}$ is an infinitely divisible random variable.
Let $r$ be a non-zero natural integer and let $X_{1}, \ldots, X_{r}$ be mutually independent Poisson random variables. Show that $\sum_{i=1}^{r} i X_{i}$ is an infinitely divisible random variable.