Soit $F$ un polynôme en deux variables, de degré $D$ et à coefficients entiers dans $[-M,M]$ pour $M\ge 3$. Alors le nombre de zéros rationnels de $F$ est soit infini soit plus petit que $M^{2^{3^{D^2}}}$. Nous montrons aussi une version plus générale sur les corps de nombres.

Si $p_k$ est le k${}^{ème}$ nombre premier, $\theta \left(p_k\right)={\sum }_{i=1}^{k}log{p}_i$ la fonction de Chebyshev. Nous obtenons de nouvelles estimations et des améliorations des bornes données par Rosser et Schoenfeld, Schoenfeld et Robin pour les fonctions$$p_k,\theta \left(p_k\right),S_k=\sum _{i=1}^k{p}_i,\text{et}S\left(x\right)=\sum _{p\le x}p.$$Ces estimations sont obtenues en utilisant des méthodes basées sur l’intégrale de Stieltjes et par calcul direct pour les petites valeurs.

We show that the set of numbers with bounded Lüroth expansions (or bounded Lüroth series) is winning and strong winning. From either winning property, it immediately follows that the set is dense, has full Hausdorff dimension, and satisfies a countable intersection property. Our result matches the well-known analogous result for bounded continued fraction expansions or, equivalently, badly approximable numbers. We note that Lüroth expansions have a countably infinite Markov partition,...

For a given sequence a boundedly expressible set is introduced. Three criteria concerning the Hausdorff dimension of such sets are proved.

Let $x=x_0{x}_1\cdots$ be a fixed point of a substitution on the alphabet $\left\{a,b\right\},$ and let $U_a=\left(\begin{array}{cc}\hfill -1& \hfill -1\\ \hfill 0& \hfill 1\end{array}\right)$ and $U_b=\left(\begin{array}{cc}\hfill 1& \hfill 1\\ \hfill 0& \hfill 1\end{array}\right)$. We give a complete classification of the substitutions $\sigma :{\left\{a,b\right\}}^{☆}$ according to whether the sequence of matrices ${\left(U_{x_0}{U}_{x_1}\cdots U_{x_n}\right)}_{n=0}^{\infty }$ is bounded or unbounded. This corresponds to the boundedness or unboundedness of the oriented walks generated by the substitutions.

We develop a new method to bound the hyperbolic and spherical Fourier coefficients of Maass forms defined with respect to arbitrary uniform lattices.

The aim of this paper is to present some computer data suggesting the correct size of bounds for exponential sums of Fourier coefficients of holomorphic cusp forms.