No Arabic abstract
For a nonincreasing function $psi$, let $textrm{Exact}(psi)$ be the set of complex numbers that are approximable by complex rational numbers to order $psi$ but to no better order. In this paper, we obtain the Hausdorff dimension and packing dimension of $textrm{Exact}(psi)$ when $psi(x)=o(x^{-2})$. We also prove that the lower bound of the Hausdorff dimension is greater than $2-tau/(1-2tau)$ when $tau=limsup_{xtoinfty}psi(x)x^2$ small enough.
Let $b ge 2$ and $ell ge 1$ be integers. We establish that there is an absolute real number $K$ such that all the partial quotients of the rational number $$ prod_{h = 0}^ell , (1 - b^{-2^h}), $$ of denominator $b^{2^{ell+1} - 1}$, do not exceed $exp(K (log b)^2 sqrt{ell} 2^{ell/2})$.
In this paper we present two efficient methods for reconstructing a rational number from several residue-modulus pairs, some of which may be incorrect. One method is a natural generalization of that presented by Wang, Guy and Davenport in cite{WGD1982} (for reconstructing a rational number from textit{correct} modular images), and also of an algorithm presented in cite{Abb1991} for reconstructing an textit{integer} value from several residue-modulus pairs, some of which may be incorrect.
We develop a lower bound sieve for primes under the (unlikely) assumption of infinitely many exceptional characters. Compared with the illusory sieve due to Friedlander and Iwaniec which produces asymptotic formulas, we show that less arithmetic information is required to prove non-trivial lower bounds. As an application of our method, assuming the existence of infinitely many exceptional characters we show that there are infinitely many primes of the form $a^2+b^8$.
Natural numbers can be divided in two non-overlapping infinite sets, primes and composites, with composites factorizing into primes. Despite their apparent simplicity, the elucidation of the architecture of natural numbers with primes as building blocks remains elusive. Here, we propose a new approach to decoding the architecture of natural numbers based on complex networks and stochastic processes theory. We introduce a parameter-free non-Markovian dynamical model that naturally generates random primes and their relation with composite numbers with remarkable accuracy. Our model satisfies the prime number theorem as an emerging property and a refined version of Cramers conjecture about the statistics of gaps between consecutive primes that seems closer to reality than the original Cramers version. Regarding composites, the model helps us to derive the prime factors counting function, giving the probability of distinct prime factors for any integer. Probabilistic models like ours can help to get deeper insights about primes and the complex architecture of natural numbers.
We give an expression of polynomials for higher sums of powers of integers via the higher order Bernoulli numbers.