English
The mgf is analytic at zero and its Taylor coefficients give the moments μ[X^n].
Русский
MGF аналитичен в нуле, а коэффициенты тейлора дают моменты μ[X^n].
LaTeX
$$$\text{AnalyticAt}(\mathrm{mgf}(X, \mu), 0) = \text{coefficients given by } \frac{\mu[X^n]}{n!}.$$$
Lean4
/-- The moment-generating function is analytic at every `t ∈ interior (integrableExpSet X μ)`. -/
theorem analyticAt_mgf (ht : t ∈ interior (integrableExpSet X μ)) : AnalyticAt ℝ (mgf X μ) t :=
by
rw [← re_complexMGF_ofReal']
exact (analyticAt_complexMGF (by simp [ht])).re_ofReal