|
BRIEF MESSAGE
On the set of exceptions in the product of sets of natural numbers with asymptotic density $1$
Yu. N. Shteinikov Federal Research Center “Research Institute of System Research
of the Russian Academy of Sciences” (Moscow)
Abstract:
The article examines the following problem. Let there be two subsets of the set of natural numbers, which we denote as $A$ and $B$. Let it also be additionally known that the asymptotic density of these sets $A,B$ is $1$. We define the set of natural numbers that are representable as the product of these sets $AB$, that is, such elements $ab$, where $a\in A, b\in B$. We study the properties of this subset of products in the set of all natural numbers. The authors S. Bettin, D. Koukoulopoulos and C. Sanna in the article [1] proved, among other things, that the density of the set $AB$ is also equal to $1$. Moreover, a quantitative version of this statement was derived, namely, an estimate was obtained for the set $\mathbb{N}\setminus AB$, which we will denote by $\overline{AB}$. Namely, by these authors, in the case when quantitative upper bounds are known for $\overline{A}\cap[1,x] =\alpha(x)x, \overline{B}\cap[1,x] = \beta(x)x, \alpha(x),\beta(x) = O(1/(\log x)^a), x\rightarrow \infty$ the upper bound on the set $\overline{AB}\cap [1,x]$ is also derived. In this paper, we study the case when $\alpha, \beta$ tend to zero slower than in the above case and somewhat refine the upper bound on the set $\overline{AB}\cap[1,x]$. In this paper we consider the case of $\alpha(x), \beta(x) = O\bigl(\frac{1}{(\log\log x)^a}\bigr)$ for some fixed $a>1$. We borrow approaches, arguments and proof scheme from the mentioned work of three authors S. Bettin, D. Koukoulopoulos and C. Sanna [1].
Keywords:
integer numbers, density, smooth numbers, product.
Received: 17.10.2022 Accepted: 24.04.2023
Citation:
Yu. N. Shteinikov, “On the set of exceptions in the product of sets of natural numbers with asymptotic density $1$”, Chebyshevskii Sb., 24:1 (2023), 237–242
Linking options:
https://www.mathnet.ru/eng/cheb1295 https://www.mathnet.ru/eng/cheb/v24/i1/p237
|
Statistics & downloads: |
Abstract page: | 35 | Full-text PDF : | 6 | References: | 10 |
|