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Non-invariant submanifolds of locally decomposable golden Riemannian manifolds Arab. J. Math. Pub Date : 2021-01-12 Mustafa Gök, Erol Kılıç
In this paper, we investigate any non-invariant submanifold of a locally decomposable golden Riemannian manifold in the case that the rank of the set of tangent vector fields of the induced structure on the submanifold by the golden structure of the ambient manifold is less than or equal to the codimension of the submanifold.
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Computing the nonabelian tensor squares of groups of order $$\pmb {p^3q}$$ p 3 q Arab. J. Math. Pub Date : 2021-01-12 O. Kalteh, S. Hadi Jafari
In this paper, we describe the explicit structures of nonabelian tensor squares of nonabelian groups of order \(p^3q\), where p and q are distinct prime numbers and \(p>2\). Our method is based on determining the structures of their Schur multipliers by applying some well-known results and the presentations of groups, which leads us to obtain the orders of their nonabelian tensor squares.
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Constructions and bounds on quaternary linear codes with Hermitian hull dimension one Arab. J. Math. Pub Date : 2021-01-09 Todsapol Mankean, Somphong Jitman
Due to their practical applications, hulls of linear codes have been of interest and extensively studied. In this paper, we focus on constructions and bounds on quaternary linear codes with Hermitian hull dimension one. Optimal \([n,2]_4\) codes with Hermitian hull dimension one are constructed for all lengths \(n\ge 3\), such that \(n \equiv 1,2,4 \ (\mathrm{mod}\ 5)\). For positive integers \(n \equiv
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On semilocal convergence of three-step Kurchatov method under weak condition Arab. J. Math. Pub Date : 2021-01-07 Himanshu Kumar
The purpose of this paper to establish the semilocal convergence analysis of three-step Kurchatov method under weaker conditions in Banach spaces. We construct the recurrence relations under the assumption that involved first-order divided difference operators satisfy the \(\omega \) condition. Theorems are given for the existence-uniqueness balls enclosing the unique solution. The application of the
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Asymptotic stability of porous-elastic system with thermoelasticity of type III Arab. J. Math. Pub Date : 2021-01-06 Ilyes Lacheheb, Salim A. Messaoudi, Mostafa Zahri
In this work, we investigate a one-dimensional porous-elastic system with thermoelasticity of type III. We establish the well-posedness and the stability of the system for the cases of equal and nonequal speeds of wave propagation. At the end, we use some numerical approximations based on finite difference techniques to validate the theoretical results.
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Estimating the moments of a random forcing field of 2D fluid from image sequences using energy minimisation method Arab. J. Math. Pub Date : 2021-01-05 Vishal Kumar Pandey, Jyotsna Singh, Harish Parthasarathy
In this paper, we consider a version of energy minimisation technique applied to images of a 2D fluid flow. The two Navier–Stokes equations describe the static flow of a 2D fluid in terms of velocity field, (u, v), pressure field, p and forcing field, f. Apart from these two Navier–Stokes equations, we have the incompressibility condition to evaluate the three parameters. While implementing this system
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Halpern–Ishikawa type iterative schemes for approximating fixed points of multi-valued non-self mappings Arab. J. Math. Pub Date : 2020-10-01 Abebe R. Tufa, M. Thuto, M. Moetele
Let C be a nonempty closed convex subset of a real Hilbert space H and \(T: C\rightarrow CB(H)\) be a multi-valued Lipschitz pseudocontractive nonself mapping. A Halpern–Ishikawa type iterative scheme is constructed and a strong convergence result of this scheme to a fixed point of T is proved under appropriate conditions. Moreover, an iterative method for approximating a fixed point of a k-strictly
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Decay rate of a weakly dissipative viscoelastic plate equation with infinite memory Arab. J. Math. Pub Date : 2020-09-24 Khaleel Anaya, Salim A. Messaoudi, Kassem Mustapha
In this paper, a weakly dissipative viscoelastic plate equation with an infinite memory is considered. We show a general energy decay rate for a wide class of relaxation functions. To support our theoretical findings, some numerical illustrations are presented at the end. The numerical solution is computed using the popular finite element method in space, combined with time-stepping finite differences
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Surjectivity of certain adjoint operators and applications Arab. J. Math. Pub Date : 2020-09-15 Amina Cherifi Hadjiat, Azzeddine Lansari
This paper is an extension and generalization of some previous works, such as the study of M. Benalili and A. Lansari. Indeed, these authors, in their work about the finite co-dimension ideals of Lie algebras of vector fields, restricted their study to fields \(X_0\) of the form \(X_0=\sum _{i=1}^{n}( \alpha _i \cdot x_i+\beta _i\cdot x_i^{1+m_i}) \frac{\partial }{\partial x_i}\), where \(\alpha _i
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Fractional flow equation in fractured aquifer using dual permeability model with non-singular kernel Arab. J. Math. Pub Date : 2020-09-07 Ritu Agarwal, Mahaveer Prasad Yadav, Ravi P. Agarwal
In this paper, a finite fractured aquifer, bounded by a stream and impervious layers on the other sides, has been considered. Variation in the level of groundwater is analyzed in confined aquifer for the unsteady flow. The governing differential equation for piezometric head involves the Caputo–Fabrizio fractional derivative operator with respect to time and is based on dual-porosity model with the
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Common fixed point iterations for a class of multi-valued mappings in $$\mathbf {CAT}(0)$$ CAT ( 0 ) spaces Arab. J. Math. Pub Date : 2020-09-05 Khairul Saleh, Hafiz Fukhar-ud-din
In this work, we propose an iterative scheme to approach common fixed point(s) of a finite family of generalized multi-valued nonexpansive mappings in a CAT(0) space. We establish and prove convergence theorems for the algorithm. The results are new and interesting in the theory of \(CAT\left( 0\right) \) spaces and are the analogues of corresponding ones in uniformly convex Banach spaces and Hilbert
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Some algebraic structures on the generalization general products of monoids and semigroups Arab. J. Math. Pub Date : 2020-08-31 Suha Ahmad Wazzan, Ahmet Sinan Cevik, Firat Ates
For arbitrary monoids A and B, in Cevik et al. (Hacet J Math Stat 2019:1–11, 2019), it has been recently defined an extended version of the general product under the name of a higher version of Zappa products for monoids (or generalized general product) \(A^{\oplus B}\)\(_{\delta }\bowtie _{\psi }B^{\oplus A}\) and has been introduced an implicit presentation as well as some theories in terms of finite
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On a DGL-map between derivations of Sullivan minimal models Arab. J. Math. Pub Date : 2020-08-18 Toshihiro Yamaguchi
For a map \(f:X\rightarrow Y\), there is the relative model \(M(Y)=(\Lambda V,d)\rightarrow (\Lambda V\otimes \Lambda W,D)\simeq M(X)\) by Sullivan model theory (Félix et al., Rational homotopy theory, graduate texts in mathematics, Springer, Berlin, 2007). Let \(\mathrm{Baut}_1X\) be the Dold–Lashof classifying space of orientable fibrations with fiber X (Dold and Lashof, Ill J Math 3:285–305, 1959])
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Boundary value problems for Caputo fractional differential equations with nonlocal and fractional integral boundary conditions Arab. J. Math. Pub Date : 2020-07-22 Choukri Derbazi, Hadda Hammouche
In this paper, we study the existence and uniqueness of solutions for fractional differential equations with nonlocal and fractional integral boundary conditions. New existence and uniqueness results are established using the Banach contraction principle. Other existence results are obtained using O’Regan fixed point theorem and Burton and Kirk fixed point. In addition, an example is given to demonstrate
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Efficient exponential timestepping algorithm using control variate technique for simulating a functional of exit time of one-dimensional Brownian diffusion with applications in finance Arab. J. Math. Pub Date : 2020-07-13 Hasan Alzubaidi
The exponential timestepping Euler algorithm with a boundary test is adapted to simulate an expected of a function of exit time, such as the expected payoff of barrier options under the constant elasticity of variance (CEV) model. However, this method suffers from a high Monte Carlo (MC) statistical error due to its exponentially large exit times with unbounded samples. To reduce this kind of error
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Bicomplex Bergman and Bloch spaces Arab. J. Math. Pub Date : 2020-07-01 L. F. Reséndis O., L. M. Tovar S.
In this article, we define the bicomplex weighted Bergman spaces on the bidisk and their associated weighted Bergman projections, where the respective Bergman kernels are determined. We study also the bicomplex Bergman projection onto the bicomplex Bloch space.
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Spectrally accurate approximate solutions and convergence analysis of fractional Burgers’ equation Arab. J. Math. Pub Date : 2020-06-24 A. K. Mittal
In this paper, a new numerical technique implements on the time-space pseudospectral method to approximate the numerical solutions of nonlinear time- and space-fractional coupled Burgers’ equation. This technique is based on orthogonal Chebyshev polynomial function and discretizes using Chebyshev–Gauss–Lobbato (CGL) points. Caputo–Riemann–Liouville fractional derivative formula is used to illustrate
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Statistical Tauberian theorems for Cesàro integrability mean based on post-quantum calculus Arab. J. Math. Pub Date : 2020-05-20 P. Parida, S. K. Paikray, B. B. Jena
The notion of statistical convergence is more general than the classical convergence. Tauberian theorems via different ordinary summability means have been established by many researchers. In the present work, we have established some new Tauberian theorems based on post-quantum calculus via statistical Cesàro summability mean of real-valued continuous function of one variable under oscillating behavior
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Strong consistency of local linear estimation of a conditional density function under random censorship Arab. J. Math. Pub Date : 2020-05-16 Abdelkader Benkhaled, Fethi Madani, Salah Khardani
In this paper, we study nonparametric local linear estimation of the conditional density of a randomly censored scalar response variable given a functional random covariate. We establish under general conditions the pointwise almost sure convergence with rates of this estimator under \(\alpha \)-mixing dependence. Finally, to show interests of our results, on the practical point of view, we have conducted
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A note on Eneström–Kakeya theorem for a polynomial with quaternionic variable Arab. J. Math. Pub Date : 2020-05-12 Dinesh Tripathi
In this paper, we present certain results concerning the location of the zeros of polynomials with quaternionic variable which generalize and refine some known Eneström–Kakeya type bounds for the zeros of polynomials.
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Dynkin game under g -expectation in continuous time Arab. J. Math. Pub Date : 2020-03-09 Helin Wu; Yong Ren; Feng Hu
In this paper, we investigate some kind of Dynkin game under g-expectation induced by backward stochastic differential equation (short for BSDE). The lower and upper value functions \(\underline{V}_t=ess\sup \nolimits _{\tau \in {\mathcal {T}_t}} ess\inf \nolimits _{\sigma \in {\mathcal {T}_t}}\mathcal {E}^g_t[R(\tau ,\sigma )]\) and \(\overline{V}_t=ess\inf \nolimits _{\sigma \in {\mathcal {T}_t}}
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Hybrid projective combination–combination synchronization in non-identical hyperchaotic systems using adaptive control Arab. J. Math. Pub Date : 2020-03-05 Ayub Khan, Harindri Chaudhary
In this paper, we investigate a hybrid projective combination–combination synchronization scheme among four non-identical hyperchaotic systems via adaptive control method. Based on Lyapunov stability theory, the considered approach identifies the unknown parameters and determines the asymptotic stability globally. It is observed that various synchronization techniques, for instance, chaos control problem
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Exponential finite difference methods for solving Newell–Whitehead–Segel equation Arab. J. Math. Pub Date : 2020-03-02 Nayrouz Hilal; Sami Injrou; Ramez Karroum
This work presents two different finite difference methods to compute the numerical solutions for Newell–Whitehead–Segel partial differential equation, which are implicit exponential finite difference method and fully implicit exponential finite difference method. Implicit exponential methods lead to nonlinear systems. Newton method is used to solve the resulting systems. Stability and consistency
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Regularity results for solutions of linear elliptic degenerate boundary-value problems Arab. J. Math. Pub Date : 2020-02-25 A. El Baraka, M. Masrour
We give an a-priori estimate near the boundary for solutions of a class of higher order degenerate elliptic problems in the general Besov-type spaces \(B^{s,\tau }_{p,q}\). This paper extends the results found in Hölder spaces \(C^s\), Sobolev spaces \(H^s\) and Besov spaces \(B^s_{p,q}\), to the more general framework of Besov-type spaces.
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On the fold thickness of graphs Arab. J. Math. Pub Date : 2020-02-19 Francis Joseph H. Campeña; Severino V. Gervacio
The graph \(G'\) obtained from a graph G by identifying two nonadjacent vertices in G having at least one common neighbor is called a 1-fold of G. A sequence \(G_0, G_1, G_2, \ldots , G_k\) of graphs such that \(G_0=G\) and \(G_i\) is a 1-fold of \(G_{i-1}\) for each \(i=1, 2, \ldots , k\) is called a uniform k-folding of G if the graphs in the sequence are all singular or all nonsingular. The fold
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Estimation of different entropies via Lidstone polynomial using Jensen-type functionals Arab. J. Math. Pub Date : 2020-02-18 Khuram Ali Khan, Tasadduq Niaz, Đilda Pečarić, Josip Pečarić
In this work, some new functional of Jensen-type inequalities are constructed using Shannon entropy, f-divergence, and Rényi divergence, and some estimates are obtained for these new functionals. Also using the Zipf–Mandelbrot law and hybrid Zipf–Mandelbrot law, we investigate some bounds for these new functionals. Furthermore, we generalize these new functionals for m-convex function using Lidstone
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Fractional integral inequalities for generalized- $$\mathbf{m }$$ m - $$((h_{1}^{p},h_{2}^{q});(\eta _{1},\eta _{2}))$$ ( ( h 1 p , h 2 q ) ; ( η 1 , η 2 ) ) -convex mappings via an extended generalized Mittag–Leffler function Arab. J. Math. Pub Date : 2019-12-09 George Anastassiou; Artion Kashuri; Rozana Liko
The authors discover a new identity concerning differentiable mappings defined on \(\mathbf{m }\)-invex set via general fractional integrals. Using the obtained identity as an auxiliary result, some fractional integral inequalities for generalized-\(\mathbf{m }\)-\(((h_{1}^{p},h_{2}^{q});(\eta _{1},\eta _{2}))\)-convex mappings by involving an extended generalized Mittag–Leffler function are presented
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Aluthge transform of operators on the Bergman space Arab. J. Math. Pub Date : 2019-11-26 Chinmayee Padhy, Pabitra Kumar Jena, S. K. Paikray
The aim of this paper is to explore some sufficient conditions for Aluthge transform of Toeplitz operators on the Bergman space to be unitary, average of unitaries and normal.
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Two-valenced association schemes and the Desargues theorem Arab. J. Math. Pub Date : 2019-11-22 Mitsugu Hirasaka, Kijung Kim, Ilia Ponomarenko
The main goal of the paper is to establish a sufficient condition for a two-valenced association scheme to be schurian and separable. To this end, an analog of the Desargues theorem is introduced for a noncommutative geometry defined by the scheme in question. It turns out that if the geometry has enough many Desarguesian configurations, then under a technical condition, the scheme is schurian and
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Almost $$*$$ ∗ -Ricci soliton on paraKenmotsu manifolds Arab. J. Math. Pub Date : 2019-09-14 V. Venkatesha, H. Aruna Kumara, Devaraja Mallesha Naik
We consider almost \(*\)-Ricci solitons in the context of paracontact geometry, precisely, on a paraKenmotsu manifold. First, we prove that if the metric g of \(\eta \)-Einstein paraKenmotsu manifold is \(*\)Ricci soliton, then M is Einstein. Next, we show that if \(\eta \)-Einstein paraKenmotsu manifold admits a gradient almost \(*\)-Ricci soliton, then either M is Einstein or the potential vector
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On compact and bounded embedding in variable exponent Sobolev spaces and its applications Arab. J. Math. Pub Date : 2019-09-12 Farman Mamedov; Sayali Mammadli; Yashar Shukurov
For a weighted variable exponent Sobolev space, the compact and bounded embedding results are proved. For that, new boundedness and compact action properties are established for Hardy’s operator and its conjugate in weighted variable exponent Lebesgue spaces. Furthermore, the obtained results are applied to the existence of positive eigenfunctions for a concrete class of nonlinear ode with nonstandard
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An approach to stability analyses in general relativity via symplectic geometry Arab. J. Math. Pub Date : 2019-08-14 Prashant Kocherlakota; Pankaj S. Joshi
We begin with a review of the statements of non-linear, linear and mode stability of autonomous dynamical systems in classical mechanics, using symplectic geometry. We then discuss what the Arnowitt–Deser–Misner (ADM) phase space and the ADM Hamiltonian of general relativity are, what constitutes a dynamical system, and subsequently present a nascent attempt to draw a formal analogy between the notions
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Free-floating planets in the Milky Way Arab. J. Math. Pub Date : 2019-07-24 L. Hamolli; M. Hafizi; F. De Paolis; A. A. Nucita
Gravitational microlensing is a powerful method to search for and characterize exoplanets, and it was first proposed by Paczyński in 1986. We provide a brief historical excursus of microlensing, especially focused on the discoveries of free-floating planets (FFPs) in the Milky Way. We also emphasize that, thanks to the technological developments, it will allow to estimate the physical parameters (in
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Neutron stars in general relativity and scalar-tensor theory of gravity Arab. J. Math. Pub Date : 2019-07-11 Farrukh J. Fattoyev
The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic mean-field framework. It is shown that astrophysical and gravitational wave observations of radii of neutron stars with masses \(M \lesssim 1.4 M_{\odot }\) constrain
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Generalized second law and universal relations of cosmological black hole Arab. J. Math. Pub Date : 2019-07-09 Ashfaque H. Bokhari; M. Akbar; Tayeb Brahimi
The objective of this paper is to investigate the validity conditions for the generalized second law of thermodynamics, and the universal relations for multi-horizon dynamical spacetime. It is found that there are three horizons of McVittie universe termed as event horizon, cosmological apparent horizon, and virtual horizon. The mass-dependent and mass-independent area product relations are formulated
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Solving Yosida inclusion problem in Hadamard manifold Arab. J. Math. Pub Date : 2019-07-09 Mohammad Dilshad
We consider a Yosida inclusion problem in the setting of Hadamard manifolds. We study Korpelevich-type algorithm for computing the approximate solution of Yosida inclusion problem. The resolvent and Yosida approximation operator of a monotone vector field and their properties are used to prove that the sequence generated by the proposed algorithm converges to the solution of Yosida inclusion problem
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A Dai–Liao conjugate gradient method via modified secant equation for system of nonlinear equations Arab. J. Math. Pub Date : 2019-07-08 M. Y. Waziri; K. Ahmed; J. Sabi’u
In this paper, we propose a Dai–Liao (DL) conjugate gradient method for solving large-scale system of nonlinear equations. The method incorporates an extended secant equation developed from modified secant equations proposed by Zhang et al. (J Optim Theory Appl 102(1):147–157, 1999) and Wei et al. (Appl Math Comput 175(2):1156–1188, 2006) in the DL approach. It is shown that the proposed scheme satisfies
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Study of a boundary value problem for fractional order $$\psi $$ ψ -Hilfer fractional derivative Arab. J. Math. Pub Date : 2019-07-06 S. Harikrishnan, Kamal Shah, K. Kanagarajan
This manuscript is devoted to the existence theory of a class of random fractional differential equations (RFDEs) involving boundary condition (BCs). Here we take the corresponding derivative of arbitrary order in \(\psi \)-Hilfer sense. By utilizing classical fixed point theory and nonlinear analysis we establish some basic results of the qualitative theory such as existence, uniqueness and stability
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The $$M^{X}/M/c$$MX/M/c Bernoulli feedback queue with variant multiple working vacations and impatient customers: performance and economic analysis Arab. J. Math. Pub Date : 2019-06-18 Amina Angelika Bouchentouf; Abdelhak Guendouzi
The present paper deals with an \(M^{X}/M/c\) Bernoulli feedback queueing system with variant multiple working vacations and impatience timers which depend on the states of the servers. Whenever a customer arrives at the system, he activates an random impatience timer. If his service has not been completed before his impatience timer expires, the customer may abandon the system. Using certain customer
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Some properties on $$\mathrm{IA_Z}$$ IA Z -automorphisms of groups Arab. J. Math. Pub Date : 2019-06-01 Hamid Taheri, Mohammd Reza R. Moghaddam, Mohammad Amin Rostamyari
Let G be a group and \(\mathrm{IA}(G)\) denote the group of all automorphisms of G, which induce identity map on the abelianized group \(G_{ab}=G/G'\). Also the group of those \(\mathrm{IA}\)-automorphisms which fix the centre element-wise is denoted by \(\mathrm{IA_Z}(G)\). In the present article, among other results and under some condition we prove that the derived subgroups of finite p-groups,
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Menon-type identities concerning additive characters Arab. J. Math. Pub Date : 2019-05-29 László Tóth
By considering even functions (\(\hbox {mod}\ n\)), we generalize a recent Menon-type identity by Li and Kim, involving additive characters of the group \({\mathbb {Z}}_n\). We use a different approach, based on certain convolutional identities. Some other applications, including related formulas for Ramanujan sums, are discussed as well.
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New modified shift-splitting preconditioners for non-symmetric saddle point problems Arab. J. Math. Pub Date : 2019-05-18 Mahin Ardeshiry; Hossein Sadeghi Goughery; Hossein Noormohammadi Pour
Zhou et al. and Huang et al. have proposed the modified shift-splitting (MSS) preconditioner and the generalized modified shift-splitting (GMSS) for non-symmetric saddle point problems, respectively. They have used symmetric positive definite and skew-symmetric splitting of the (1, 1)-block in a saddle point problem. In this paper, we use positive definite and skew-symmetric splitting instead and present
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New Riemann–Liouville fractional Hermite–Hadamard type inequalities for harmonically convex functions Arab. J. Math. Pub Date : 2019-05-18 Zeynep Şanlı; Mehmet Kunt; Tuncay Köroğlu
In this paper, we proved two new Riemann–Liouville fractional Hermite–Hadamard type inequalities for harmonically convex functions using the left and right fractional integrals independently. Also, we have two new Riemann–Liouville fractional trapezoidal type identities for differentiable functions. Using these identities, we obtained some new trapezoidal type inequalities for harmonically convex functions
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Effects of geometric optics in conformal Weyl gravity Arab. J. Math. Pub Date : 2019-05-17 A. Abdujabbarov; A. Hakimov; B. Turimov; A. Tursunov
We have investigated effect of geometric optics as the rotation of polarization vector of light in spacetime of gravitational compact object in the fourth-order theory of conformal Weyl gravity. The Pineault–Roeder method is applied to the rotating Weyl metric, and analytical results are obtained in the limit of weak field and or slow rotation. For the photon traveling parallel to the symmetry axes
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On classical n -absorbing submodules Arab. J. Math. Pub Date : 2019-04-15 Osama A. Naji
Let R a commutative ring with identity and M be a unitary R-module. In this paper, we investigate some properties of n-absorbing submodules of M as a generalization of 2-absorbing submodules. We also define the classical n-absorbing submodule, a proper submodule N of an R-module M is called a classical n-absorbing submodule if whenever \(a_1 a_2\ldots a_{n+1} m\in N\) for \(a_1, a_2,\ldots , a_{n+1}\in
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Gravitational collapse of baryonic and dark matter Arab. J. Math. Pub Date : 2019-04-01 Dipanjan Dey; Pankaj S. Joshi
A massive star undergoes a continual gravitational collapse when the pressures inside the collapsing star become insufficient to balance the pull of gravity. The Physics of gravitational collapse of stars is well studied. Using general relativistic techniques, one can show that the final fate of such a catastrophic collapse can be a black hole or a naked singularity, depending on the initial conditions
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An extension of the Bessel–Wright transform in the class of Boehmians Arab. J. Math. Pub Date : 2019-03-14 Imane Berkak; El Mehdi Loualid; Radouan Daher
In this paper, we first construct a suitable Boehmian space on which the Bessel–Wright transform can be defined and some desired properties are obtained in the class of Boehmians. Some convergence results are also established.
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A Zygmund-type integral inequality for polynomials Arab. J. Math. Pub Date : 2019-03-13 Abdullah Mir
Let P(z) be a polynomial of degree n which does not vanish in \(|z|<1\). Then it was proved by Hans and Lal (Anal Math 40:105–115, 2014) that$$\begin{aligned} \Bigg |z^s P^{(s)}+\beta \dfrac{n_s}{2^s}P(z)\Bigg |\le \dfrac{n_s}{2}\Bigg (\bigg |1+\dfrac{\beta }{2^s}\bigg |+\bigg | \dfrac{\beta }{2^s}\bigg |\Bigg )\underset{|z|=1}{\max }|P(z)|, \end{aligned}$$for every \(\beta \in \mathbb C\) with \(|\beta
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Penalized Partial Least Square applied to structured data Arab. J. Math. Pub Date : 2019-03-04 Camilo Broc; Borja Calvo; Benoit Liquet
Nowadays, data analysis applied to high dimension has arisen. The edification of high-dimensional data can be achieved by the gathering of different independent data. However, each independent set can introduce its own bias. We can cope with this bias introducing the observation set structure into our model. The goal of this article is to build theoretical background for the dimension reduction method
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The generic model of general relativity Arab. J. Math. Pub Date : 2019-03-04 Michael Tsamparlis; Andronikos Paliathanasis
We develop a generic spacetime model in general relativity which can be used to build any gravitational model within general relativity. The generic model uses two types of assumptions: (a) geometric assumptions in addition to the inherent geometric identities of the Riemannian geometry of spacetime and (b) assumptions defining a class of observers by means of their four-velocity \(u^{a}\) which is
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Non-static spherically symmetric spacetimes and their conformal Ricci collineations Arab. J. Math. Pub Date : 2019-03-04 Fawad Khan; Tahir Hussain; Ashfaque Hussain Bokhari; Sumaira Saleem Akhtar
For a perfect fluid matter, we present a study of conformal Ricci collineations (CRCs) of non-static spherically symmetric spacetimes. For non-degenerate Ricci tenor, a vector field generating CRCs is found subject to certain integrability conditions. These conditions are then solved in various cases by imposing certain restrictions on the Ricci tensor components. It is found that non-static spherically
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Local linear conditional cumulative distribution function with mixing data Arab. J. Math. Pub Date : 2019-02-26 Oussama Bouanani; Saâdia Rahmani; Larbi Ait-Hennani
This paper investigates a conditional cumulative distribution of a scalar response given by a functional random variable with an \(\alpha \)-mixing stationary sample using a local polynomial technique. The main purpose of this study is to establish asymptotic normality results under selected mixing conditions satisfied by many time-series analysis models in addition to the other appropriate conditions
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O -Cross Gram matrices with respect to $$\varvec{g}$$ g -frames Arab. J. Math. Pub Date : 2019-02-19 Ali Akbar Arefijamaal; Mitra Shamsabadi
The matrix representation of operators in Hilbert spaces is a useful tool in applications. It is important to present the matrix representation by sequences other than orthonormal bases. In this paper, we extend the matrix representation of operators using g-frames and investigate their invertibility and stability.
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Weighted averages of n -convex functions via extension of Montgomery’s identity Arab. J. Math. Pub Date : 2019-02-16 Asif R. Khan; Josip E. Pečarić; Marjan Praljak
Using an extension of Montgomery’s identity and the Green’s function, we obtain new identities and related inequalities for weighted averages of n-convex functions, i.e. the sum \(\sum _{i=1}^m \rho _i h(\lambda _i)\) and the integral \(\int ^{b}_{a} \rho (\lambda ) h(\gamma (\lambda ))d\lambda \) where h is an n-convex function.
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Seeing the halo rotation of nearby spiral galaxies using Planck data Arab. J. Math. Pub Date : 2019-02-07 Noraiz Tahir; Francesco De Paolis; Asghar Qadir; Achille A. Nucita
The rotation of the galactic halos is a fascinating topic which is still waiting to be addressed. Planck data have shown the existence of a temperature asymmetry towards the halo of several nearby galaxies, such as M31, NGC 5128, M33, M81 and M82. However, the cause of this asymmetry is an open problem. A possibility to explain the observed effect relies on the presence of “cold gas clouds” populating
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Chebyshev collocation treatment of Volterra–Fredholm integral equation with error analysis Arab. J. Math. Pub Date : 2019-02-04 Y. H. Youssri; R. M. Hafez
This work reports a collocation algorithm for the numerical solution of a Volterra–Fredholm integral equation (V-FIE), using shifted Chebyshev collocation (SCC) method. Some properties of the shifted Chebyshev polynomials are presented. These properties together with the shifted Gauss–Chebyshev nodes were then used to reduce the Volterra–Fredholm integral equation to the solution of a matrix equation
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Approximation by (p,q) Szász-beta–Stancu operators Arab. J. Math. Pub Date : 2019-02-01 Prerna Maheshwari Sharma; Mohammed Abid
Motivated by recent investigations, in this paper we introduce (p, q)-Szász-beta–Stancu operators and investigate their local approximation properties in terms of modulus of continuity. We also obtain a weighted approximation and Voronovskaya-type asymptotic formula.
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A closed-form solution to the inverse problem in interpolation by a Bézier-spline curve Arab. J. Math. Pub Date : 2019-01-31 Le Phuong Quan; Thái Anh Nhan
A geometric construction of a Bézier curve is presented by a unifiable way from the mentioned literature with some modification. A closed-form solution to the inverse problem in cubic Bézier-spline interpolation will be obtained. Calculations in the given examples are performed by a Maple procedure using this solution.
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On a function involving generalized complete ( p , q )-elliptic integrals Arab. J. Math. Pub Date : 2019-01-31 Barkat Ali Bhayo; Li Yin
Motivated by the work of Alzer and Richards (Anal Math 41:133–139, 2015), here authors study the monotonicity and convexity properties of the function$$\begin{aligned} \Delta _{p,q} (r) = \frac{{E_{p,q}(r) - \left( {r'} \right) ^p K_{p,q}(r) }}{{r^p }} - \frac{{E'_{p,q}(r) - r^p K'_{p,q}(r) }}{{\left( {r'} \right) ^p }}, \end{aligned}$$where \(K_{p,q}\) and \(E_{p,q}\) denote the complete (p, q)-elliptic
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Linearization criteria for two-dimensional systems of third-order ordinary differential equations by complex approach Arab. J. Math. Pub Date : 2019-01-28 Hina M. Dutt; M. Safdar; Asghar Qadir
Linearization criteria for two-dimensional systems of second-order ordinary differential equations (ODEs) have been derived earlier using complex symmetry analysis. For such systems, the linearizable form, linearization criteria and symmetry group classification are presented. In this paper, we extend the complex approach to obtain a complex-linearizable form of two-dimensional systems of third-order
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