The purpose of the present article is the study of duals of functional codes on algebraic surfaces. We give a direct geometrical description of them, using differentials. Even if this description is less trivial, it can be regarded as a natural extension to surfaces of the result asserting that the dual of a functional code $C_L(D,G)$ on a curve is the differential code $C_{\Omega }(D,G)$ . We study the parameters of such codes and state a lower bound for their minimum distance. Using this bound, one can study some examples...

Let A, D, K, k ∈ ℕ with D square free and 2 ∤ k,B = 1,2 or 4 and ${\mu }_i\in -1,1(i=1,2)$, and let $h(-2^{1-e}D)(e=0or1)$ denote the class number of the imaginary quadratic field $\mathbb{Q}\left(\surd (-2^{1-e}D)\right)$. In this paper, we give the all-positive integer solutions of the Diophantine equation Ax² + μ₁B = K((Ay² + μ₂B)/K)ⁿ, 2 ∤ n, n > 1 and we prove that if D > 1, then $h(-2^{1-e}D)\equiv 0\left(modn\right)$, where D, and n satisfy $kⁿ-2^{e+1}=Dx²$, x ∈ ℕ, 2 ∤ n, n > 1. The results are valuable for the realization of quadratic field cryptosystem.

Nous donnons ici deux résultats sur le déterminant $\zeta$-régularisé ${det}_{\zeta }A$ d’un opérateur de Schrödinger $A={\Delta }_g+V$ sur une variété compacte $ℳ$. Nous construisons, pour $ℳ=S^1\times S^1$, une suite $(G_n,{\rho }_n,{\Delta }_n)$ où $G_n$ est un graphe fini qui se plonge dans $ℳ$ via ${\rho }_n$ de telle manière que ${\rho }_n\left(G_n\right)$ soit une triangulation de $ℳ$ et où ${\Delta }_n$ est un laplacien discret sur $G_n$ tel que pour tout potentiel $V$ sur $ℳ$, la suite de réels $det({\Delta }_n+V)$ converge après renormalisation vers ${det}_{\zeta }({\Delta }_g+V)$. Enfin, nous donnons sur toute variété riemannienne compacte $(ℳ,g)$ de dimension inférieure ou égale à $3$...

This paper deals with implications defined from disjunctive uninorms $U$ by the expression $I(x,y)=U\left(N\right(x),y)$ where $N$ is a strong negation. The main goal is to solve the functional equation derived from the distributivity condition of these implications over conjunctive and disjunctive uninorms. Special cases are considered when the conjunctive and disjunctive uninorm are a $t$-norm or a $t$-conorm respectively. The obtained results show a lot of new solutions generalyzing those obtained in previous works when the implications...