An explicit result for short sums of positive arithmetic functions
Olivier Bordellès
TL;DR
The paper resolves the challenge of obtaining fully explicit, uniform bounds for short sums of nonnegative arithmetic functions obeying a mild growth condition, via a refined Erdős-Wolke–Shiu framework and Rankin-type methods. It proves a totally explicit Main Theorem bounding short sums in terms of $\sum_{n\le x} f(n)/n$ with explicitly defined constants, applicable to a broad class of functions satisfying $f(mn)\le \tau_k(m) f(n)$. The results yield explicit short-interval estimates for Hooley’s $Δ$-function, including a bound for $\sum_{x-y<n≤x} Δ(n)$ and a restricted-omega variant, both with computable constants. The combination of new Shiu refinements, explicit handling of non-multiplicativity via Rankin, and detailed prime-sum controls provides the first broadly explicit short-sum bounds in this setting, with direct consequences for the distribution of $Δ_k$ in short intervals. Overall, the work delivers fully explicit, practically usable bounds that enhance the quantitative understanding of short sums and Hooley’s Δ-function in analytic number theory.
Abstract
We prove a totally explicit bound for short sums of certain non-negative arithmetic functions satisfying a general growth condition, and apply this result to derive two explicit estimates for the Erdős-Hooley $Δ$-function in short intervals.
