Approximation of Smooth Numbers for Harmonic Samples A Stein method Approach
Arturo Jaramillo, Xiaochuan Yang
TL;DR
This work develops a probabilistic framework for understanding the content of $m$-smooth numbers up to $n$ by introducing $ Psi_H[m,n]$, the harmonic-measure analogue of the classical count $ Psi(n,m)$. The authors model prime multiplicities via independent geometric random variables and prove a sharp Dickman-type approximation using Stein's method for the Dickman distribution, with key regularity inputs from Bhattacharjee and Schulte. The main result provides a uniform, explicit sup-norm approximation: $ Psi_H(n,m) = rac{n}{6(n,m)} I[ ho](6(n,m)) + O(1/ log n)$ for $16\le m\nle n$, where $6(n,m)=rac{ log n}{ log m}$ and $ I[ ho](x)= int_0^x ho(s)\,ds$, connecting to the Dickman function $ ho$. The analysis relies on a two-step program: (i) a stochastic representation of $H_n$ via $oldsymbol{\xi_p}$ and convergence to the Dickman law, and (ii) a sup-norm bound derived from the Dickman Stein equation and Mertens formulas; these results situate a probabilistic route alongside classical de Bruijn-type asymptotics and offer a framework potentially informative for questions related to Hildebrand’s criterion and the Riemann hypothesis.
Abstract
We present a de Bruijn type approximation for quantifying the content of m smooth numbers, derived from samples obtained through a probability measure over the set of integers less than or equal to n, with point mass function at k inversely proportional to k. Our analysis is based on a stochastic representation of the measure of interest, utilizing weighted independent geometric random variables. This representation is analyzed through the lens of Stein method for the Dickman distribution. A pivotal element of our arguments relies on precise estimations concerning the regularity properties of the solution to the Dickman Stein equation for heaviside functions, recently developed by Bhattacharjee and Schulte. Remarkably, our arguments remain mostly in the realm of probability theory, with Mertens first and third theorems standing as the only number theory estimations required.
