Displaying 21 – 40 of 295

Showing per page

Séries formelles et produit de Hadamard

Abdelkader Necer (1997)

Journal de théorie des nombres de Bordeaux

Nous nous intéressons ici essentiellement à l’algèbre de Hadamard des séries formelles. Si des résultats importants ont été obtenus dans le cas d’une variable, il n’en est pas de même dans le cas de plusieurs variables. En effet, beaucoup de problèmes posés restent encore sans réponse. C’est le cas par exemple du problème du quotient de Hadamard, ou celui de la caractérisation des éléments de Hadamard inversibles, ou les diviseurs de zéro, ou encore le problème des multiplicateurs de certains sous-ensembles...

Sets of k -recurrence but not ( k + 1 ) -recurrence

Nikos Frantzikinakis, Emmanuel Lesigne, Máté Wierdl (2006)

Annales de l’institut Fourier

For every k , we produce a set of integers which is k -recurrent but not ( k + 1 ) -recurrent. This extends a result of Furstenberg who produced a 1 -recurrent set which is not 2 -recurrent. We discuss a similar result for convergence of multiple ergodic averages. We also point out a combinatorial consequence related to Szemerédi’s theorem.

Short remark on Fibonacci-Wieferich primes

Jiří Klaška (2007)

Acta Mathematica Universitatis Ostraviensis

This paper has been inspired by the endeavour of a large number of mathematicians to discover a Fibonacci-Wieferich prime. An exhaustive computer search has not been successful up to the present even though there exists a conjecture that there are infinitely many such primes. This conjecture is based on the assumption that the probability that a prime p is Fibonacci-Wieferich is equal to 1 / p . According to our computational results and some theoretical consideratons, another form of probability can...

Sidon basis in polynomial rings over finite fields

Wentang Kuo, Shuntaro Yamagishi (2021)

Czechoslovak Mathematical Journal

Let 𝔽 q [ t ] denote the polynomial ring over 𝔽 q , the finite field of q elements. Suppose the characteristic of 𝔽 q is not 2 or 3 . We prove that there exist infinitely many N such that the set { f 𝔽 q [ t ] : deg f < N } contains a Sidon set which is an additive basis of order 3 .

Sign changes of certain arithmetical function at prime powers

Rishabh Agnihotri, Kalyan Chakraborty (2021)

Czechoslovak Mathematical Journal

We examine an arithmetical function defined by recursion relations on the sequence { f ( p k ) } k and obtain sufficient condition(s) for the sequence to change sign infinitely often. As an application we give criteria for infinitely many sign changes of Chebyshev polynomials and that of sequence formed by the Fourier coefficients of a cusp form.

Currently displaying 21 – 40 of 295