English

Distance between natural numbers based on their prime signature

Number Theory 2021-11-02 v3 Probability

Abstract

We define a new metric between natural numbers induced by the \ell_\infty norm of their unique prime signatures. In this space, we look at the natural analog of the number line and study the arithmetic function L(N)L_\infty(N), which tabulates the cumulative sum of distances between consecutive natural numbers up to NN in this new metric. Our main result is to identify the positive and finite limit of the sequence L(N)/NL_\infty(N)/N as the expectation of a certain random variable. The main technical contribution is to show with elementary probability that for K=1,2K=1,2 or 33 and ω0,,ωK2\omega_0,\ldots,\omega_K\geq 2 the following asymptotic density holds limn{Mn:  Mj<ωj for j=0,,K}n=p:prime ⁣(1j=0K1pωj) . \lim_{n\to\infty}\frac{\big|\big\{M\leq n:\; \|M-j\|_\infty <\omega_j \text{ for } j=0,\ldots,K \big\}\big|}{n} = \prod_{p:\, \mathrm{prime}}\! \bigg( 1- \sum_{j=0}^K\frac{1}{p^{\omega_j}} \bigg)~. This is a generalization of the formula for kk-free numbers, i.e. when ω0==ωK=k\omega_0=\ldots=\omega_K=k. The random variable is derived from the joint distribution when K=1K=1. As an application, we obtain a modified version of the prime number theorem. Our computations up to N=1012N=10^{12} have also revealed that prime gaps show a considerably richer structure than on the traditional number line. Moreover, we raise additional open problems, which could be of independent interest.

Keywords

Cite

@article{arxiv.2005.02027,
  title  = {Distance between natural numbers based on their prime signature},
  author = {István B. Kolossváry and István T. Kolossváry},
  journal= {arXiv preprint arXiv:2005.02027},
  year   = {2021}
}

Comments

This article supersedes arXiv:1711.02903. v3: accepted version in J. Number Theory with additional Appendix. v2: Conjecture 1 and 2 of v1 are now proved, major revision of exposition

R2 v1 2026-06-23T15:18:58.785Z