ThmDex – An index of mathematical definitions, results, and conjectures.
Characteristic function of standard Poisson random natural number
Formulation 0
Let $X \in \text{Poisson}(1)$ be a D5524: Standard Poisson random natural number.
Let $t \in \mathbb{R}$ be a D993: Real number.
Then \begin{equation} \mathbb{E}(e^{i t X}) = e^{(e^{i t} - 1)} \end{equation}
Formulation 1
Let $X \in \text{Poisson}(1)$ be a D5524: Standard Poisson random natural number.
Let $t \in \mathbb{R}$ be a D993: Real number.
Then \begin{equation} \mathfrak{F}_X(t) = \exp\left( e^{i t} - 1 \right) \end{equation}
Proofs
Proof 0
Let $X \in \text{Poisson}(1)$ be a D5524: Standard Poisson random natural number.
Let $t \in \mathbb{R}$ be a D993: Real number.
This result is a particular case of R3904: Characteristic function of a Poisson random natural number. $\square$