This survey deals with pluri-periodic harmonic functions on lattices with values in a field of positive characteristic. We mention, as a motivation, the game “Lights Out” following the work of Sutner [20], Goldwasser- Klostermeyer-Ware [5], Barua-Ramakrishnan-Sarkar [2, 19], Hunzikel-Machiavello-Park [12] e.a.; see also [22, 23] for a more detailed account. Our approach uses harmonic analysis and algebraic geometry over a field of positive characteristic.

Soit $E$ une courbe elliptique sur $\mathbb{Q}$ par un modèle de Weierstrass généralisé :$$y^2+A_{1}xy+A_{3}y=x^3+A_2{x}^2+A_{4}x+A_6;A_i\in \mathbb{Z}.$$Soit $M=(a/d^2,b/d_3)$ avec $(a,d)=1$, un point rationnel sur cette courbe. Pour tout entier $m$, on exprime les coordonnées de $mM$ sous la forme :$$mM=\left(\frac{{\phi }_m\left(M\right)}{{\psi }_n^2\left(m\right)},\frac{{\omega }_m\left(M\right)}{{\psi }_m^3\left(M\right)}\right)=\left(\frac{{\widehat{\phi }}_m}{d^2{\widehat{\psi }}_m^2},\frac{{\widehat{\omega }}_m}{d^3{\widehat{\psi }}_m^3}\right),$$où ${\phi }_m,\psi \_m,{\omega }_m\in \mathbb{Z}[A_1,\cdots ,A_6,x,y]$ et ${\widehat{\phi }}_m$, ${\widehat{\psi }}_m$, ${\widehat{\omega }}_m$ sont déduits par multiplication par des puissances convenables de $d$.Soit $p$ un nombre premier impair et supposons que $M\left(\mathrm{mod}p\right)$ est non singulier et que le rang d’apparition de $p$ dans la suite d’entiers $\left({\widehat{\psi }}_m\right)$ est supérieur ou égal à trois. Notons ce rang par $r=r\left(p\right)$ et soit ${\nu }_p({\widehat{\psi }}_r)=e_0\ge 1$. Nous montrons que la suite $\left({\widehat{\psi }}_m\right)$...

In this paper, we characterize the substitutions over a three-letter alphabet which generate a ultimately periodic sequence.

In this paper, we characterize the substitutions over a three-letter alphabet which generate a ultimately periodic sequence.

We are interested in permutations preserving certain distribution properties of sequences. In particular we consider $\mu$-uniformly distributed sequences on a compact metric space $X$, 0-1 sequences with densities, and Cesàro summable bounded sequences. It is shown that the maximal subgroups, respectively subsemigroups, of $Aut\left(\mathbf{N}\right)$ leaving any of the above spaces invariant coincide. A subgroup of these permutation groups, which can be determined explicitly, is the Lévy group $𝒢$. We show that $𝒢$ is big in the...

Let K be a finite Galois extension of the field ℚ of rational numbers. We prove an asymptotic formula for the number of Piatetski-Shapiro primes not exceeding a given quantity for which the associated Frobenius class of automorphisms coincides with any given conjugacy class in the Galois group of K/ℚ. In particular, this shows that there are infinitely many Piatetski-Shapiro primes of the form a² + nb² for any given natural number n.

Integer sequences of the form $\lfloor n^c\rfloor$, where 1 < c < 2, can be locally approximated by sequences of the form ⌊nα+β⌋ in a very good way. Following this approach, we are led to an estimate of the difference ${\sum }_{n\le x}\phi \left(\lfloor n^c\rfloor \right)-1/c{\sum }_{n\le x^c}\phi \left(n\right)n^{1/c-1}$, which measures the deviation of the mean value of φ on the subsequence $\lfloor n^c\rfloor$ from the expected value, by an expression involving exponential sums. As an application we prove that for 1 < c ≤ 1.42 the subsequence of the Thue-Morse sequence indexed by $\lfloor n^c\rfloor$ attains both of its values with asymptotic...