Annali dell''Universita di Ferrara最新文献

In this paper, we establish a best proximity point theorem by using a newly defined condensing operator, and we applied the results to investigate the optimum solution of a system of fractional integral equations followed by an example.

In this work, we consider a coupled system of two wave equations with only one thermal effect in a one-dimensional domain. We give the well-posedness using the semigroup theory and show that the solution of the system decays polynomially by constructing an appropriate Lyapunov function.

Nada M. Al-Thani introduced pure closed submodules without adding any details about the behavior of this kind of submodule. The main goal of this paper is to study and develop pure closed submodules. We introduced several results that are analogous to those in the closed submodule. Besides that, we study pure closed submodules in multiplication modules. Also, the relationships of pure closed submodules with (St)-closed and (W)-closed submodules are investigated. Moreover, ACC on pure closed submodules is discussed.

The generalization of the monomiality principle for q-special polynomials has just been explained and demonstrated. This extension is used to study the monomiality features of the number of q-special polynomials, such as q-Appell polynomials, q-Gould–Hopper polynomials, two variables q-Hermite, q-Laguerre and q-Legendre polynomials. Additionally, several kinds of hybrid q-special polynomials and their monomiality features are studied, such as two-variable q-Laguerre-Appell polynomials, two-variable based q-Hermite-Appell polynomials and q-Gould–Hopper–Appell polynomials. This study seeks to generate the q-Legendre–Gould–Hopper polynomials and then describe their attributes by extending the idea of monomiality for q-polynomials. Furthermore, we propose operational representations, expansion formulae and new families of these polynomials with the aid of q-operational methods and extension for monomiality principle of q-polynomials.

This paper addresses the existence of weak solutions for a class of nonlinear Dirichlet boundary value problems governed by a double phase operator. The main results are established under precise assumptions on the nonlinearity of the second term. The analysis is carried out within the advanced framework of Musielak-Orlicz-Sobolev spaces, which accommodate the variable growth conditions induced by the double phase structure. To handle challenges related to weak convergence, we employ the Young measures technique. Additionally, approximate solutions are systematically constructed through the Galerkin method, ensuring a rigorous and structured approach to the problem.

This work considers the 3-D stochastic fractional Navier-Stokes equation driven by multiplicative noise in critical Fourier-Besov-Morrey spaces (mathcal {Fdot{N}}_{p,h,r}^{1-2beta +frac{3}{p^{prime }}+frac{h}{p}}(mathbb {R}^{3})). We establish the local existence and uniqueness of the solutions to the concerned equation and we prove the global existence in the probabilistic sense when the initial data are small.

In this paper, we define and study a new class of bounded linear operators which is a generalization of the class of (m-)symmetric operators. Let m be a strictly positive integer number and (Uin {mathcal {B}}({mathcal {H}})) is a unitary operator, an operator (Tin {mathcal {B}}({mathcal {H}})) is said to be a ((U,m)-)symmetry if it commutes with U such that

It is shown that if T is a ((U,m)-)symmetry, then (T^{p}) is a ((U^{p},m)-)symmetry. We study the product and the sum of such a class. Moreover, if T is a ((U,m)-)symmetry and m is even, we obtain that T is a ((U,m-1)-)symmetry. We prove that if Q is a nilpotent operator of order n which commutes with both T and U, then (T+Q) is a ((U,m+2n-2)-)symmetry. Also, we give some spectral properties of ((U,m)-)symmetric operators. Finally, we show further results concerning this class of operators on a finite dimensional Hilbert space.

In this paper, we introduce a broad class of metrics on the slit tangent bundle of Finsler manifolds, referred to as F-natural metrics. These metrics are analogous to the well-established g-natural metrics on tangent bundles of Riemannian manifolds and are defined by six real functions on the domain of positive real numbers. We present an in-depth analysis of conformal, homothetic, and Killing vector fields associated with specific lifts of vector fields and tensor sections on the slit tangent bundle, equipped with a general pseudo-Riemannian F-natural metric. Notably, we prove that the geodesic vector field cannot be conformal and that, with respect to certain families of F-natural metrics, the Liouville vector field can indeed be conformal, homothetic, or Killing on the slit tangent bundle.

Let R be prime ring with characteristic different from 2, C denotes the extended centroid, L a Lie ideal of R and (Q_r) the right Martindale quotient of the ring R. Let (Delta _1) and (Delta _2) represents two generalized skew derivations of R associated with ((psi ,l_1)) and ((psi , l_2)), respectively, such that (psi .l_1=l_1.psi ) and (psi . l_2= l_2.psi ). If, for every (r in L), (Delta _1^2(r)r=Delta _2(r^2)), then we characterize the maps (Delta _1) and (Delta _2). As an application of this generalization, we proved that if (Delta _1(tau ^2)=0) for all (tau in R), then R contains a non-zero central ideal.

It is pointed out that: (1) the positive version of the parallel postulate appearing in Pambuccian (Ann Univ Ferrara 71: 17, 2025) can be found in a 1935 manuscript by Paul Bernays and in Grundlagen der Mathematik, vol. II by Hilbert and Bernays; and (2) that axiom S appearing in the same paper is almost identical to Axiom IV in F. P. Jenks’ 1940 incidence-based axiom system for hyperbolic geometry.