• Ricerche mat. (IF 0.97) Pub Date : 2020-11-23
R. K. Anand

We presented a geometrical shock dynamics model to predict the behavior of weak converging shock waves in solid materials. Taking into consideration Mie–Grüneisen equation of state the analytical solution is obtained for the flow behind the converging shock-front propagating in solids. The analytical formaluas are also obtained for the shock velocity, pressure, density, particle velocity, temperature

更新日期：2020-11-25
• Ricerche mat. (IF 0.97) Pub Date : 2020-11-23
José Sabina Lis, Sergio Segura de León

This work discusses the existence of the limit as p goes to 1 of the nontrivial solutions to the one-dimensional problem: \begin{aligned} {\left\{ \begin{array}{ll} -\left( |u_x|^{p-2} u_x\right) _x = \lambda |{u}|^{{p}-2}{u} -|{u}|^{{q}-2}{u}&{} \quad 0< x < 1\\ u(0)=u(1)=0, &{} \end{array}\right. } \end{aligned} where $$\lambda$$ is a positive parameter and the exponents p, q satisfy $$1< p 更新日期：2020-11-23 • Ricerche mat. (IF 0.97) Pub Date : 2020-11-20 Bruno Leonardo Macedo Ferreira, Ivan Kaygorodov Suppose \({\mathfrak R}\,$$ is a 2,3-torsion free unital alternative ring having an idempotent element $$e_1$$ $$\left( e_2 = 1-e_1\right)$$ which satisfies $$x {\mathfrak R}\, \cdot e_i = \{0\} \Rightarrow x = 0$$ $$\left( i = 1,2\right)$$. In this paper, we aim to characterize the commuting maps. Let $$\varphi$$ be a commuting map of $${\mathfrak R}\,$$ so it is shown that $$\varphi (x) = zx 更新日期：2020-11-21 • Ricerche mat. (IF 0.97) Pub Date : 2020-11-04 Angela Alberico, Patrizia Di Gironimo Let \(X = \{X_1,X_2, \ldots ,X_m\}$$ be a system of smooth vector fields in $${{\mathbb R}^n}$$ satisfying the Hörmander’s finite rank condition. We prove the following Sobolev inequality with reciprocal weights in Carnot-Carathéodory space $$\mathbb G$$ associated to system X\begin{aligned} \left( \frac{1}{\int _{B_R} K(x)\; dx} \int _{B_R} |u|^{t} K(x) \; dx \right) ^{1/t} \le C\, R \left( \frac{1}{\int 更新日期：2020-11-04 • Ricerche mat. (IF 0.97) Pub Date : 2020-10-26 Xiaosong Tang, Jieying Luo, Shan Zhou, Changyuan Yan In this paper, we investigate a mixed fractional integral boundary value problem with p(t)-Laplacian operator. Firstly, we derive the Green function through the direct computation and obtain the properties of Green function. For $$p(t)\ne$$ constant, under the appropriate conditions of the nonlinear term, we establish the existence result of at least one positive solution of the above problem by means 更新日期：2020-10-30 • Ricerche mat. (IF 0.97) Pub Date : 2020-10-22 Abdelali Sabri, Ahmed Jamea In this paper, we prove the existence and uniqueness results of entropy solutions to a class of nonlinear parabolic p(u)-Laplacian problem with Fourier-type boundary conditions and $$L^1$$-data. The main tool used here is the Rothe method combined with the theory of variable exponent Sobolev spaces. 更新日期：2020-10-30 • Ricerche mat. (IF 0.97) Pub Date : 2020-10-15 Annamaria Barbagallo, Vincenzo Esposito The Cauchy problem for a class of hyperbolic operators with triple characteristics is analyzed. Some a priori estimates in Sobolev spaces with negative indexes are proved. Subsequently, an existence result for the Cauchy problem is obtained. 更新日期：2020-10-16 • Ricerche mat. (IF 0.97) Pub Date : 2020-10-09 Fernando Farroni We establish asymptotic stability estimates for solutions to evolution problems with singular convection term. Such quantitative estimates provide a measure with respect to the time variable of the distance between the solution to a parabolic problem from the one of the its elliptic stationary counterpart. 更新日期：2020-10-11 • Ricerche mat. (IF 0.97) Pub Date : 2020-09-24 Alberto Fiorenza, Jarno Talponen We extend the algebraic construction of finite dimensional varying exponent $$L^{p(\cdot )}$$ space norms, defined in terms of Cauchy polynomials to a more general setting, including varying exponent $$L^{p(\cdot )}$$ spaces. This boils down to reformulating the Musielak–Orlicz or Nakano space norm in an algebraic fashion where the infimum appearing in the definition of the norm should become a (uniquely 更新日期：2020-09-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-09-19 Amiran Gogatishvili, Pankaj Jain, Saikat Kanjilal The main aim of this paper to provide several scales of equivalent conditions for the bilinear Hardy inequalities in the case $$1< q, p_1, p_2<\infty$$ with $$q \ge \max (p_1,p_2)$$. 更新日期：2020-09-20 • Ricerche mat. (IF 0.97) Pub Date : 2020-09-11 Wafa Selmi, Mohsen Timoumi We study the existence of fast homoclinic orbits for the following damped vibration system $$\ddot{u}(t)+q(t)\dot{u}(t)+\nabla V(t,u(t))=0$$; where $$q\in C(\mathbb {R},\mathbb {R})$$ and $$V\in C^{1}(\mathbb {R}\times \mathbb {R}^{N},\mathbb {R})$$ is of the type V(t,x)=-K(t,x)+W(t,x). A map K is not a quadratic form in x and W(t, x) is superquadratic in x. 更新日期：2020-09-12 • Ricerche mat. (IF 0.97) Pub Date : 2020-08-01 Anastasia V. Vikulova In this paper we show how the method of parallel coordinates can be extended to three dimensions. As an application, we prove the conjecture of Antunes et al. (Adv Calc Var 10:357–380, 2017) that “the ball maximises the first Robin eigenvalue with negative boundary parameter among all convex domains of equal surface area” under the weaker restriction that the boundary of the domain is diffeomorphic 更新日期：2020-08-01 • Ricerche mat. (IF 0.97) Pub Date : 2020-07-31 Antonella Nastasi We use a variational approach to study existence and regularity of solutions for a Neumann p-Laplacian problem with a reaction term on metric spaces equipped with a doubling measure and supporting a Poincaré inequality. Trace theorems for functions with bounded variation are applied in the definition of the variational functional and minimizers are shown to satisfy De Giorgi type conditions. 更新日期：2020-08-01 • Ricerche mat. (IF 0.97) Pub Date : 2020-07-15 Colin Rogers A Lagrangian version of the classical 1+1-dimensional Korteweg capillarity system is shown to encapsulate as a particular reduction an integrable Boussinesq equation. The associated integrability of the corresponding Eulerian capillarity system is set down. In turn, hidden integrability cases of the generalised Boussinesq equation are recorded associated with reduction of the Eulerian system to the 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-07-06 Giovanni Nastasi, Vittorio Romano The Boltzmann equation for charge transport in monolayer graphene is numerically solved by using a discontinuous Galerkin method. The numerical fluxes are based on a uniform non oscillatory reconstruction. The numerical scheme has been tested by simulating the electron dynamics in a graphene field effect transistor. To the best of our knowledge the presented simulations are the first ones using a full 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-07-01 T. Saanouni This notes studies the inhomogeneous non-linear Schrödinger equations with a harmonic potential\begin{aligned} i\partial _tu +\Delta u-|x|^2u+|x|^{b}|u|^{p-1}u=0. \end{aligned}$$Indeed, following the methods of Fukuizumi and Ohta (Differ Integral Equ 16(6):691–706, 2003), Ohta (Funccialaj Ekvacioj 61:135–143, 2018), the non-linear and strong instability of standing waves are obtained in the two 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-06-30 Rahul Kumar Chaturvedi, L. P. Singh The motivation of this study is to analyze the structure of the Riemann solutions for compressible hyperbolic system, so called logotropic system, with a Coulomb-type friction. The classical wave solutions of the Riemann problem (RP) for the logotropic system are structured explicitly for all cases. The system considered in this problem is hyperbolic in nature and the characteristic fields associated 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-06-30 Deepika Singh, Rajan Arora, Astha Chauhan In the present paper, we use a Lie group of transformations to obtain a class of similarity solutions to a problem of cylindrically symmetric strong shock waves propagating through one-dimensional, unsteady, and isothermal flow of a self-gravitating ideal gas under the influence of azimuthal magnetic field. The density of the ambient medium is assumed to be non-uniform ahead of the shock. The generators 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-06-27 Danhua Wang, Wenjun Liu Feng (Complexity, Art. 5139419, 2020) studied a thermoelastic laminated Timoshenko beam, where the heat conduction is given by Cattaneo’s law, as well as established the exponential and polynomial stabilities depending on the stability number $$\chi _\tau$$. In this short paper, we consider the same system and show a lack of exponential stability when the stability number $$\chi _\tau \ne 0$$, by 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-06-05 Paolo Maremonti, Francesca Crispo, Carlo Romano Grisanti The paper is concerned with the IBVP of the Navier–Stokes equations. The goal is to evaluate the possible gap between the energy equality and the energy inequality deduced for a weak solution. This kind of analysis is new and the result is a natural continuation and improvement of a result obtained by the same authors in Crispo et al. (Some new properties of a suitable weak solution to the Navier–Stokes 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-06-03 Xuanlong Ma, Huadong Su The power graph $${\mathcal {P}}_{G}$$ of a finite group G is the graph whose vertex set is G, two distinct vertices are adjacent if one is a power of the other. The order supergraph $${\mathcal {S}}_{G}$$ of $${\mathcal {P}}_G$$ is the graph with vertex set G, and two distinct vertices x, y are adjacent if o(x)|o(y) or o(y)|o(x). In this paper, we study the independence number of $${\mathcal {S}}_{G}$$ 更新日期：2020-07-24 • Ricerche mat. (IF 0.97) Pub Date : 2020-05-19 Fahad Al Basir, Santanu Ray Control interventions and farming knowledge are equally important for plant disease control. In this article, a mathematical model has been derived using saturated response functions (nonlinear infection rate) for studying the dynamics of mosaic disease with farming awareness based roguing (removal of infected plants) and insecticide spraying . It is assumed that the use of roguing and spraying depend 更新日期：2020-05-19 • Ricerche mat. (IF 0.97) Pub Date : 2020-04-27 Dimitri Breda, Davide Liessi Recently, systems of coupled renewal and retarded functional differential equations have begun to play a central role in complex and realistic models of population dynamics. In view of studying the local asymptotic stability of equilibria and (mainly) periodic solutions, we propose a pseudospectral collocation method to approximate the eigenvalues of the evolution operators of linear coupled equations 更新日期：2020-04-27 • Ricerche mat. (IF 0.97) Pub Date : 2020-04-09 Bruno Buonomo A mathematical model is proposed to assess the effects of a vaccine on the time evolution of a coronavirus outbreak. The model has the basic structure of SIRI compartments (susceptible–infectious–recovered–infectious) and is implemented by taking into account of the behavioral changes of individuals in response to the available information on the status of the disease in the community. We found that 更新日期：2020-04-09 • Ricerche mat. (IF 0.97) Pub Date : 2020-04-06 Konstantin B. Blyuss, Fahad Al Basir, Victoria A. Tsygankova, Liudmyla O. Biliavska, Galyna O. Iutynska, Serhii N. Kyrychko, Serhii V. Dziuba, Olexandr I. Tsyliuryk, Olexandr O. Izhboldin A major challenge to successful crop production comes from viral diseases of plants that cause significant crop losses, threatening global food security and the livelihoods of countries that rely on those crops for their staple foods or source of income. One example of such diseases is a mosaic disease of plants, which is caused by begomoviruses and is spread to plants by whitefly. In order to mitigate 更新日期：2020-04-06 • Ricerche mat. (IF 0.97) Pub Date : 2020-03-11 Salvatore Cuomo, Vittorio Di Somma, Federica Sica In this paper we aim to compare a popular numerical method with a new, recently proposed meshless approach for Heston PDE resolution. In finance, most famous models can be reformulated as PDEs, which are solved by finite difference and Monte Carlo methods. In particular, we focus on Heston model PDE and we solve it via radial basis functions (RBF) methods and alternating direction implicit. RBFs have 更新日期：2020-03-11 • Ricerche mat. (IF 0.97) Pub Date : 2020-03-07 A. Marasco, F. Giannino, A. Iuorio Plant–soil feedback is recognized as a causal mechanism for the emergence of vegetation patterns of the same species especially when water is not a limiting resource (e.g. humid environments) (Cartenì et al. in J Theor Biol 313:153–161, 2012. https://doi.org/10.1016/j.jtbi.2012.08.008; Marasco et al. in Bull Math Biol 76(11):2866–2883, 2014. https://doi.org/10.1007/s11538-014-0036-6). Nevertheless 更新日期：2020-03-07 • Ricerche mat. (IF 0.97) Pub Date : 2020-03-06 Musa Rabiu, Robert Willie, Nabendra Parumasur In this paper, we develop a new disease-resistant mathematical model with a fraction of the susceptible class under imperfect vaccine and treatment of both the symptomatic and quarantine classes. With standard incidence when the associated reproduction threshold is less than unity, the model exhibits the phenomenon of backward bifurcation, where a stable disease-free equilibrium co-exists with a stable 更新日期：2020-03-06 • Ricerche mat. (IF 0.97) Pub Date : 2020-03-06 Nadia Raïssi, Mustapha Serhani, Ezio Venturino In this paper we propose a non linear mathematical model describing the process of biodegradation of organic pollutants by means of fungi, and using glucose to sustain its metabolism and growth. Two aspects are investigated, firstly, we study equilibria and their stability for this model, and analyze the sensitivity of the persistence equilibrium with respect to some model parameters. Secondly, optimal 更新日期：2020-03-06 • Ricerche mat. (IF 0.97) Pub Date : 2020-02-13 Malay Banerjee, Bob W. Kooi, Ezio Venturino The objective is the study of the dynamics of a prey–predator model where the prey species can migrate between two patches. The specialist predator is confined to the first patch, where it consumes the prey following the simple law of mass action. The prey is further “endangered” in that it suffers from the strong Allee effect, assumed to occur due to the lowering of successful matings. In the second 更新日期：2020-02-13 • Ricerche mat. (IF 0.97) Pub Date : 2020-02-04 Xinchang Wang, Xiaosong Tang, Zhiwei Wang, Xiaolin Li The distributed delay was firstly proposed by Volterra in the 1930s since it is more realistic than discrete delay and has been introduced in many dynamical systems. In this paper, we establish a diffusive viral infection model with general incidence function and distributed delays subject to the homogeneous Neumann boundary conditions. Firstly, we prove the existence, uniqueness, positivity and boundedness 更新日期：2020-02-04 • Ricerche mat. (IF 0.97) Pub Date : 2020-02-04 A. M. Grundland, A. J. Hariton In this paper, it is shown how a combination of approximate symmetries of a nonlinear wave equation with small dissipations and singularity analysis provides exact analytic solutions. We perform the analysis using the Lie symmetry algebra of this equation and identify the conjugacy classes of the one-dimensional subalgebras of this Lie algebra. We show that the subalgebra classification of the integro-differential 更新日期：2020-02-04 • Ricerche mat. (IF 0.97) Pub Date : 2019-12-17 S. N. Raw, B. Tiwari, P. Mishra In this paper, we consider a three species plankton–fish system that incorporates external toxicity and nonlinear harvesting. We consider that the growth of species are affected directly or indirectly by an external toxic substance and the feeding of the predator on the affected prey is considered as Holling type II functional response. All the possible biological feasible equilibrium points are determined 更新日期：2019-12-17 • Ricerche mat. (IF 0.97) Pub Date : 2019-11-18 Lorand Gabriel Parajdi This paper provides a complete analysis of the stability of the steady-states for a three-dimensional system modeling cell dynamics after bone marrow transplantation in chronic myeloid leukemia. There are given results for both chronic and accelerated-acute phases of the disease. 更新日期：2019-11-18 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-25 Patrizia Di Gironimo We study the Dirichlet problem for a second order linear elliptic partial differential equation with discontinuous coefficients in unbounded domains. We establish an existence and uniqueness result. 更新日期：2019-10-25 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-24 Dario Esposito; Francesco de Giovanni; Marco Trombetti This paper provides an account of results and methods from the theory of infinite groups admitting only finitely many normalizers of subgroups with a given property. Some new statements on this subject are also proved. 更新日期：2019-10-24 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-22 Maria Francesca Betta; Adele Ferone; Gabriella Paderni We consider a class of Dirichlet boundary problems for nonlinear degenerate elliptic equations with lower order terms. We prove, using symmetrization techniques, pointwise estimates for the rearrangement of the gradient of a solution u and integral estimates. As consequence, we get apriori estimates which show how the summability of the gradient of a solution increases when the summability of the datum 更新日期：2019-10-22 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-19 Justin Dekeyser; Jean Van Schaftingen We prove that the range of sequence of vector measures converging widely satisfies a weak lower semicontinuity property, that the convergence of the range implies the strict convergence (convergence of the total variation) and that the strict convergence implies the range convergence for strictly convex norms. In dimension 2 and for Euclidean spaces of any dimensions, we prove that the total variation 更新日期：2019-10-19 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-18 Colin Rogers; Giuseppe Saccomandi; Luigi Vergori The propagation of localised (in space-time) waves is analysed in the context of the dynamic theory of incompressible hyperelastic solids subject to body forces corresponding to a dual power-law substrate potential. A broad class of exact solutions is obtained which, under the assumption of slow modulation, incorporates Helmholtz-type solitary waves. The linear stability of these solutions is studied 更新日期：2019-10-18 • Ricerche mat. (IF 0.97) Pub Date : 2019-10-04 Davide Franco; Luciano Amito Lomonaco We prove that some of the main results of linkage theory can be extended to a more general context in homological algebra. Our main result states that, under suitable circumstances, if one has a morphism among two objects in an abelian category, both equipped with a good resolution, then there is a canonical procedure to build up a good resolution for the cokernel of the dual morphism. 更新日期：2019-10-04 • Ricerche mat. (IF 0.97) Pub Date : 2019-09-28 Syed Mohammad Abdal; Surendra Kumar This article studies approximate controllability for a new class of semilinear control systems involving state-dependent delay in Hilbert space setting. We formulate some new sufficient conditions which ensure the existence of mild solution for the considered system via the Schauder fixed point theorem. We use the theory of fundamental solution and fractional powers of operator, to establish our major 更新日期：2019-09-28 • Ricerche mat. (IF 0.97) Pub Date : 2019-09-24 A. Taiwo; L. O. Jolaoso; O. T. Mewomo We propose a general alternative regularization algorithm for solving the split equality fixed point problem for the class of quasi-pseudocontractive mappings in Hilbert spaces. We also illustrate the performance of our algorithm with numerical example and compare the result with some other algorithms in the literature in this direction. We found out that our algorithm requires a lesser number of iterations 更新日期：2019-09-24 • Ricerche mat. (IF 0.97) Pub Date : 2019-09-07 Zbigniew Lipecki Here is a corrected version of the Abstract. 更新日期：2019-09-07 • Ricerche mat. (IF 0.97) Pub Date : 2019-08-30 M. Bahari; R. El Arabi; M. Rhoudaf We shall give the existence of a capacity solution to a nonlinear elliptic coupled system, whose unknowns are the temperature inside a semiconductor material, u, and the electric potential, $$\varphi$$, the model problem we refer to is$$\begin{aligned} \left\{ \begin{array}{l} \Delta _p u+g(x,u)= \rho (u)|\nabla \varphi |^2 \quad \mathrm{in} \quad \Omega ,\\ {{\,\mathrm{div}\,}}(\rho (u)\nabla \varphi

更新日期：2019-08-30
• Ricerche mat. (IF 0.97) Pub Date : 2019-08-10
Ali Molkhasi

Let R and S be two commutative rings with unity, let I be an ideal of S and $$\varphi : R \longrightarrow S$$ be a ring homomorphism. In this paper, we give a characterization for the the amalgamated algebra $$R \bowtie ^\varphi I$$ to be an Artinian ring.

更新日期：2019-08-10
• Ricerche mat. (IF 0.97) Pub Date : 2019-07-25
Vijay Kumar, Joydip Dhar, Harbax S. Bhatti

In this study, a three species plant-pest-natural enemy compartmental model incorporating gestation delays for both pests and natural enemies in a polluted environment is proposed. The boundedness and positivity properties of the model are established. Equilibria and their stability analysis are carried out for all possible steady states. The existence of Hopf bifurcation in the system is analyzed

更新日期：2019-07-25
• Ricerche mat. (IF 0.97) Pub Date : 2019-07-23
Faten Toumi; Om Kalthoum Wanassi

In this work, we consider the following nonlinear fractional differential equation\begin{aligned} {\left\{ \begin{array}{ll} -D^{\nu } u(t)=\lambda f(t,u(t))+e(t) \ \ \ in \ \ (0,1),\\ u^{(j)}(0)=0, \ \ 0\le j \le n-2, \ \ [D^{\alpha } u(t)]_{t=1}=0,\\ \end{array}\right. } \end{aligned}where $$\lambda >0$$ is a parameter, $$n \ge 3$$, $$n-1< \nu < n$$, $$1 \le \alpha \le n-2$$ and $$D^{\nu }$$

更新日期：2019-07-23
• Ricerche mat. (IF 0.97) Pub Date : 2019-07-16
I. I. Kinzina; O. S. Logunova; L. V. Smirnova; O. A. Torshina

In this paper we investigate the uniqueness of potential recovery in the inverse Borg–Levinson problem, and our study deals with a model of its recovery. The article applies the theory of elliptic equations. Using the resolvent method, in fact, we obtain uniqueness conditions for potential recovery in the inverse Borg–Levinson problem with Newton’s boundary condition considered on a multidimensional

更新日期：2019-07-16
• Ricerche mat. (IF 0.97) Pub Date : 2019-07-01
Cristina Bertone; Francesca Cioffi

In this paper, we investigate the behavior of almost reverse lexicographic ideals with the Hilbert function of a complete intersection. More precisely, over a field K, we give a new constructive proof of the existence of the almost revlex ideal $$J\subset K[x_1,\ldots ,x_n]$$, with the same Hilbert function as a complete intersection defined by n forms of degrees $$d_1\le \cdots \le d_n$$. Properties

更新日期：2019-07-01
• Ricerche mat. (IF 0.97) Pub Date : 2019-06-13
Abdelhafid Salmani; Youssef Akdim; Hicham Redwane

We prove the existence of an entropy solution for a class of nonlinear anisotropic elliptic unilateral problem associated to the following equation\begin{aligned} -\sum _{i=1}^{N} \partial _i a_i(x,u, \nabla u) -\sum _{i=1}^{N}\partial _{i}\phi _{i}( u)=\mu , \end{aligned}where the right hand side $$\mu$$ belongs to $$L^{1}(\Omega )+ W^{-1, \vec {p'}}(\Omega )$$. The operator $$-\sum _{i=1}^{N} 更新日期：2019-06-13 • Ricerche mat. (IF 0.97) Pub Date : 2019-06-11 David E. Dobbs; Noômen Jarboui This paper extends the concept of a normal pair from commutative ring theory to the context of a pair of (associative unital) rings. This is done by using the notion of integrality introduced by Atterton. It is shown that if \(R \subseteq S$$ are rings and $$D=(d_{ij})$$ is an $$n\times n$$ matrix with entries in S, then D is integral (in the sense of Atterton) over the full ring of $$n\times n$$ matrices

更新日期：2019-06-11
• Ricerche mat. (IF 0.97) Pub Date : 2019-06-10
Najib Mahdou; Moutu Abdou Salam Moutui

Let $$f : A \rightarrow B$$ be a ring homomorphism and J be an ideal of B. In this paper, we give a characterization of zero divisors of the amalgamation which is a generalization of Maimani’s and Yassemi’s work (see Maimani and Yassemi in J Pure Appl Algebra 212(1):168–174, 2008). Furthermore, we investigate the transfer of Prüfer domain concept to commutative rings with zero divisors in the amalgamation

更新日期：2019-06-10
• Ricerche mat. (IF 0.97) Pub Date : 2019-06-01
Ali Taghavi; Roja Hosseinzadeh; Efat Nasrollahi

Let $$\mathcal {A}$$ be a standard operator algebra on a Banach space $$\mathcal {X}$$ with $$\dim \mathcal {X}\ge 3$$. In this paper, we determine the form of the bijective maps $$\phi :\mathcal {A}\longrightarrow \mathcal {A}$$ satisfying\begin{aligned} \phi \left( \frac{1}{2}(AB^2+B^2A)\right) = \frac{1}{2}[\phi (A)\phi (B)^{2}+\phi (B)^{2}\phi (A)], \end{aligned}for every A,B \in \mathcal 更新日期：2019-06-01 • Ricerche mat. (IF 0.97) Pub Date : 2019-05-24 Saeid Tahmasebi; Maria Longobardi; Farid Foroghi; Fazlollah Lak In this paper, we consider a shift-dependent measure of generalized cumulative entropy and its dynamic (past) version in the case where the weight is a general non-negative function. Our results include linear transformations, stochastic ordering, bounds and aging classes properties and some relationships with other survival concepts. We also define the conditional weighted generalized cumulative entropy 更新日期：2019-05-24 • Ricerche mat. (IF 0.97) Pub Date : 2019-05-18 W. F. Pfeffer We prove that in a Banach space with the metric approximation property the flat chains defined by De Pauw and Hardt (Am J Math 134:1–69, 2012) coincide with those of Adams (J Geom Anal 18:1–28, 2008). 更新日期：2019-05-18 • Ricerche mat. (IF 0.97) Pub Date : 2019-05-15 K. O. Aremu; L. O. Jolaoso; C. Izuchukwu; O. T. Mewomo In this paper, we use the gate condition on two multivalued k-demicontractive mappings to approximate a common solution of a finite family of monotone inclusion problem and fixed point problem in CAT(0) space. Furthermore, we propose a Halpern-type proximal point algorithm and prove its strong convergence to a common solution of a finite family of monotone inclusion problems and fixed point problem 更新日期：2019-05-15 • Ricerche mat. (IF 0.97) Pub Date : 2019-05-15 Elhoussine Azroul; Farah Balaadich We prove the existence of solutions for a quasilinear elliptic system\begin{aligned} \left\{ \begin{array}{ll} -\text {div}\,\sigma (x,u,Du)&{}=f(x,u,Du)\quad \text {in}\;\varOmega ,\\ u&{}=0\quad \text {on}\;\partial \varOmega . \end{array} \right. \end{aligned}The results are obtained in Orlicz–Sobolev spaces by means of the Young measures. 更新日期：2019-05-15 • Ricerche mat. (IF 0.97) Pub Date : 2019-04-30 Pradeep Kumar Let G be a group. An automorphism \(\alpha of G is called a commuting automorphism if $$\alpha (x)x= x \alpha (x)$$ for all $$x \in G$$. The set of all commuting automorphisms of G is denoted by A(G). The set A(G) does not necessarily form a subgroup of the automorphism group of G. If A(G) form a subgroup, then we say G is an A-group. In this paper, we show that the direct product of two finite

更新日期：2019-04-30
• Ricerche mat. (IF 0.97) Pub Date : 2019-04-13
Andrea Sacchetti

In this talk we discuss some recent results I obtained for a class of nonlinear models in quantum mechanics. In particular we focus our attention to the nonlinear one-dimensional Schrodinger equation with a periodic potential and a Stark-type perturbation. In the limit of large periodic potential the Stark–Wannier ladders of the linear equation become a dense energy spectrum because a cascade of bifurcations

更新日期：2019-04-13
• Ricerche mat. (IF 0.97) Pub Date : 2019-04-06
M. Hayes; N. H. Scott

A combination $$\varvec{a}+{\mathrm{i}}\varvec{b}$$ where $${\mathrm{i}}^2=-1$$ and $$\varvec{a},\,\varvec{b}$$ are real vectors is called a bivector. Gibbs developed a theory of bivectors, in which he associated an ellipse with each bivector. He obtained results relating pairs of conjugate semi-diameters and in particular considered the implications of the scalar product of two bivectors being zero

更新日期：2019-04-06
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