private lemma hasDerivAt_rpow_logpow {x : ℝ} (hx : 0 < x) (ρ : ℝ) (n : ℕ) :
HasDerivAt (fun p => x ^ p * (Real.log x) ^ n)
(x ^ ρ * (Real.log x) ^ (n + 1)) ρ := by
convert (hasDerivAt_rpow hx ρ).mul_const ((Real.log x) ^ n) using 1
ringThe Cumulant Tower: Higher-Order Bridges Between CES and Escort Statistics