theorem escortCentralMoment_zero_at_symmetry [NeZero J]
{c : ℝ} (hc : 0 < c) (ρ : ℝ) {n : ℕ} (hn : 1 ≤ n) :
escortCentralMoment (fun _ : Fin J => c) ρ n = 0 := by
unfold escortCentralMoment
-- The mean is log c
have hmean : escortExpectation (fun _ : Fin J => c) ρ
(fun _ => Real.log c) = Real.log c :=
escort_expectation_const _ (fun _ => hc) ρ (Real.log c)
-- Simplify: log(c) for constant input
simp only [hmean, sub_self, zero_pow (by omega : n ≠ 0)]
exact escort_expectation_const _ (fun _ => hc) ρ 0The Cumulant Tower: Higher-Order Bridges Between CES and Escort Statistics