Higher derivatives of the Gram function
The work studies the asymptotics of higher-order derivatives of the Gram function t_u and of the related functions S(t) and the Riemann-Siegel theta function. It also asks whether the powers t_u^n are uniformly distributed modulo one, in both the discrete and continuous sense.
Asymptotic formulas for S^{(n)}(t) are derived from the Riemann-von Mangoldt formula, using differentiation under the integral sign for the error term δ(t). Uniform distribution follows from a monotonicity criterion on derivatives. The results were formalized in Lean v4.29.1, with code written using Claude Opus and other LLMs. In the formalization, S is generalized to a class of functions built from arbitrary step functions with discrete jump sets.
The paper proves S^{(n)}(t) = (-1)^{n-1}(n-2)!/(2π) t^{1-n} + O(t^{-n-1}) and the uniform distribution modulo one of t_u^n. The Lean project has over 10,000 lines, builds without sorry, uses only standard axioms, and is publicly available on GitHub.
