Hamidreza Rahimi

We define $wt_0$-distance which is a special type of $wt$-distance and obtain some best proximity point theorems involving $b$-simulation functions. Our results are significant, since we replace simulation function with $b$-simulation function, metric space with $b$-metric space, and $w_0$-distance and $wt$-distance with $wt_0$-distance. We also pr...

The aim of this paper is to prove some existence and uniqueness theorems of the fixed points for Hardy-Rogers type contraction with respect to a $wt$-distance in $b$-metric spaces endowed with a graph. These results prepare a more general statement, since we apply the condition of orbitally $G$-continuity of mappings instead of the condition of con...

In this paper, we define T-quasi-contractions of Ciric and Fisher type with respect to the w-distance and introduce several fixed point theorems using such contractions and distances on complete metric spaces. Then, we show that these theorems are equivalent to existing results. Ultimately, by using of Minkowski functional, we solve the open proble...

In this paper we study the existence of the fixed points for Hardy-Rogers type mappings with respect to a wt-distance in partially ordered metric spaces. Our results provide a more general statement, since we replace a w-distance with a wt-distance and ordered metric spaces with ordered b-metric spaces. Some examples are presented to validate our o...

In this paper, we introduce operator p , h -convex functions and establish a Hermite–Hadamard inequality for these functions. As application, we obtain several trace and singular value inequalities of operators.

In this article, applying the concept of a generalized c -distance in cone b -metric spaces over Banach algebra with a nonnormal solid cone therein, we establish several common fixed point theorems for two noncontinuous mappings satisfying the Han-Xu-type contraction. Our results are interesting, since they are not equivalent to former well-known r...

In this paper, we consider the concept of cone b-metric spaces over Banach algebras and obtain some fixed point results for various definitions of contractive mappings. Moreover, we discuss about the property P and the property Q of fixed point problems. Our results are significant, since we omit the assumptions of normality of cones under which ca...

The volterra-fredholm integral equation in all forms are arose from physics, biology and engineering problems which is derived from differential equation modelling. On the other hand, the trained programming algorithm by the fuzzy artificial neural networks has effective solution to find the best answer. In this article we try to estimate the equat...

In this paper, we consider weakly compatible mappings with respect to a generalized c-distance in cone b-metric spaces and obtain new common fixed-point theorems. Our results provide a more general statement, since we need not to nor the continuity of mappings and nor the normality of cone. In particular, we refer to the results of M. Abbas and G....

In this paper, a new and applied concept of topological spaces based upon relations is introduced. These topological spaces are called R-topological spaces and SR-topological spaces. Some of the properties of these spaces and their relationship with the initial topological space are verified. Moreover, some of their applications for example in fixe...

The purpose of this paper is to introduce the notion of R-metric spaces and give a real generalization of Banach fixed point theorem. Also, we give some conditions to construct the Brouwer fixed point. As an application, we find the existence of solution for a fractional integral equation.

In this note, it is shown that if (fi,gi)i=1∞∈Lp(Rd)×Lq(Rd) is a Schauder frame for a closed subspace X of Lp(Rd), then X embeds almost isometrically into lp. Also, the same conclusion holds, if for f∈Lp(Rd), the translations f by {xi:xi∈Rd} is a bounded minimal system for X. A basis (frame) for the Banach space Lp[0,1]2, 1≤p

In this work, we define the concept of a generalized c-distance in cone b-metric spaces over a Banach algebra and introduce some its properties. Then, we prove the existence and uniqueness of fixed points for mappings satisfying weak contractive conditions such as Han–Xu-type contraction and Cho-type contraction with respect to this distance. Our a...

The aim of this paper is to prove some existence and uniqueness results of the fixed points for Hardy-Rogers type contraction in cone metric spaces associated with a 𝑐-distance and endowed with a graph. These results prepare a more general statement, since we apply the condition of orbitally 𝐺-continuity of mapping instead of the condition of conti...

In this work, we define the concept of a w-b-cone distance in t v s -cone b-metric spaces which differs from generalized c-distance in cone b-metric spaces, and we discuss its properties. Our results are significant, since all of the results in fixed point theory with respect to a generalized c-distance can be introduced in the version of w-b-cone...

The main purpose of this paper is to investigate the character amenability of semigroup algebras. In this regard, the new concept character amenability modulo an ideal of Banach algebras are introduced. For a large class of semigroups such as E-inversive E-semigroup and eventually inverse semigroups, it is shown that the semigroup S is amenable if...

Biprojectivity and biflatness of Banach algebras are investigated in this paper. In particular we characterize the biprojectivity and biflatness of quotient Banach algebras by introducing the new notions of biprojectivity and biflatness modulo an ideal of Banach algebras. As an application, by using the presented results we give a version of Helems...

Some characterizations of character amenability and approximate character amenability of Banach algebras are investigated. In this respect, the new concept character amenability modulo an ideal and approximate character amenability modulo an ideal of Banach algebras are introduced. As an application of the obtained results, character amenability an...

We consider the notion of generalized c-distance in the setting of ordered cone b-metric spaces and obtain some new fixed point results. Our results provide a more general statement, under which can be unified some theorems of the existing literature. In particular, we refer to the results of Sintunavarat et al. [W. Sintunavarat, Y.J. Cho, P. Kumam...

Using the Nehari manifold and variational methods, the existence and multiplicity of positive solutions for the multi-singular semilinear elliptic system with critical growth terms in bounded domains are investigated. In addition, under appropriate assumptions, it is shown that the system has at least two positive solutions when the pair of the par...

In this paper some generalized notions of amenability modulo an ideal of Banach algebras such as uniformly (boundedly) approximately amenable (contractible) modulo an ideal of Banach algebras are investigated. Using the obtained results, uniformly (boundedly) approximately amenability (contractibility) modulo an ideal of weighted semigroup algebras...

A similarity solution for a steady laminar mixed convection boundary layer flow of a nanofluid near the stagnation point on a vertical permeable plate with a magnetic field and a buoyancy force is obtained by solving a system of nonlinear ordinary differential equations. These equations are solved analytically by using a new kind of a powerful anal...

The aim of this paper is to investigate the amenability modulo, an ideal of Banach algebras with emphasis on applications to homological algebras. In doing so, we show that amenability modulo, an ideal of A** implies amenability modulo, an ideal of A. Finally, for a large class of semigroups, we prove that l¹(S)** is amenable modulo Iσ** if and onl...

The aim of this paper is to investigate the amenability modulo, an ideal of Banach algebras with emphasis on applications to homological algebras. In doing so, we show that amenability modulo, an ideal of A * * implies amenability modulo, an ideal of A. Finally, for a large class of semigroups, we prove that l 1 ( S ) * * is amenable modulo I σ * *...

In this paper we introduce and study the concept of approximate amenability (contractibility) modulo an ideal of Banach algebras. Based on the obtained results, we prove that the weighted semigroup algebra ℓ 1 (S, ω) is approximately amenable modulo an ideal if and only if S is amenable and ωσ is diagonally bounded where ωσ is the induced weight on...

In the present work, we introduce the notion of algebraic cone b-metric spaces, which is a generalization of algebraic cone metric space. Then we prove that for every complete algebraic b-metric space there exists a correspondent isomorphic complete usual (associated) b-metric space via two approach (nonlinear scalarization function and Minkowski f...

In this paper we prove some common fixed point theorems by using the generalized distance in a cone metric space. Our theorems extend some recent results of Wang and Guo [Appl. Math. Lett. 24 (2011) 1735-1739] and Abbas and Jungck [J. Math. Anal. Appl. 341 (2008) 416-420].

In this paper we are continuing the study of the concept of amenability modulo an ideal of Banach algebras which is an extension of the usual notion of amenability. Analogous to the amenability of Banach algebra, we show the relation between amenability modulo an ideal of Banach algebra and its unitization

In this paper, we compare relation between n-tuple fixed point results and fixed point theorems in abstract metric spaces and metric-like spaces. Actually, we show that the results of n-tuple fixed point can be obtained from fixed point theorems and conversely. Thus, some recent results about both fixed points and n-tuple fixed points are equivalen...

The notion of coupled fixed point was introduced in 2006 by Bhaskar and Lakshmikantham. On the other hand, Filipovićet al. [M. Filipovićet al., “Remarks on “Cone metric spaces and fixed-point theorems of T-Kannan and T-Chatterjea contractive mappings”,” Math. Comput. Modelling 54, 1467–1472 (2011)] proved several fixed and periodic point theorems f...

The notion of coupled fixed point was initiated in 2006 by Bhaskar and Lakshmikantham. On the other hand, Radenovi´c and Kadelburg [S. Radenovi´c, Z. Kadelburg, Quasicontractions on symmetric and cone symmetric spaces, Banach J. Math. Anal. 5 (1) (2011) 3850] defined cone metric type space and proved several fixed point theorems. In this paper we i...

A vector metric space is a generalization of a metric space, where the metric is Riesz space valued. We prove some common fixed point theorems for four mappings in ordered vector metric spaces. Obtained results extend and generalize well-known comparable results in the literature.

In this paper we prove some common fixed point theorems by using the generalized distance in a cone metric space. Our theorems extend some recent results of Wang and Guo [Appl. Math. Lett. 24 (2011) 1735-1739] and Abbas and Jungck [T. Math. Anal. Appl. 341 (2008) 416-420].

Abstract. We investigate the amenability of the semigroup algebras �1(S/ρ), where ρ is a group congruence (not necessarily minimal) on a semigroup S. We relate this to a new notion of amenability of Banach algebras modulo an ideal, to prove a version of Johnson’s theorem for a large class of semigroups, including inverse semigroups, E-inversive sem...

In this paper we introduce the notion of T-contraction for tripled fixed points in abstract metric spaces and obtain some tripled fixed point theorems which extend and generalize well-known comparable results in the literature. To support our results, we present an example and an applications to integral equations.

In this paper, we consider cone metric type spaces which are introduced as a generalization of symmetric and metric spaces by Khamsi and Hussain [M.A. Khamsi and N. Hussain, Nonlinear Anal. 73 (2010), 3123-3129]. Then we prove several fixed and periodic point theorems in cone metric type spaces.

In this paper, we prove some common tripled fixed point and tripled coincidence point results for contractive conditions in a cone metric type space. Our results extend, unify and generalize well-known results in the literature, in particular the recent results of Aydi et al. (Fixed Point Theory Appl 2012:134, 2012). Some examples are also presente...

In this paper we investigate some hereditary properties of amenability modulo an ideal of Banach algebras. We show that if (eα)α is a bounded approximate identity modulo I of a Banach algebra A and X is a neo-unital modulo I, then (eα)α is a bounded approximate identity for X. Moreover we show that amenability modulo an ideal of a Banach algebra A...

We investigate the concept of amenability modulo an ideal of Banach algebra, showing that amenability modulo an ideal can be characterized by the existence of virtual and approximate diagonal modulo an ideal. We also study the concept of contractible modulo an ideal of Banach algebra. As a consequence, we prove a version of Selivanov's theorem for...

In this paper we consider compactification spaces of ideal extension for topological semigroups. As a consequence, we characterize compactification spaces for Brandt λ-extension of topological semigroups.

In this paper we present a family of analysis and synthesis systems of operators with frame-like properties for the range of a bounded operator on a separable Hilbert space. This family of operators is called a Θ–g-frame, where Θ is a bounded operator on a Hilbert space. Θ–g-frames are a generalization of g-frames, which allows to reconstruct eleme...

In this paper, several xed point theorems for T-contraction of two maps on cone metric spaces under normality condition are proved. Obtained results extend and generalize well-known comparable results in the literature.

We present a generalization of several fixed and common fixed point theorems on c -distance in ordered cone metric spaces. In this way, we improve and generalize various results existing in the literature.

In this paper we define the concept of a coupled common fixed point for contractive conditions in a cone metric type space and prove some coupled common fixed point theorems. In the sequel, we obtain a general approach for our theorems. These results extend, unify and generalize several well known comparable results in the existing literature.

We investigate the concept of amenability modulo an ideal of Banach algebra, showing that amenability modulo an ideal can be characterized by the existence of virtual and approximate diagonal modulo an ideal. We also study the concept of contractible modulo an ideal of Banach algebra. As a consequence, we prove a version of Selivanov's theorem for...

We present a generalization of several fixed and common fixed point theorems on c -distance in ordered cone metric spaces. In this way, we improve and generalize various results existing in the literature.

In this paper, we consider cone metric type spaces which are introduced as a generalization of symmetric and metric spaces by Khamsi and Hussain [M.A. Khamsi and N. Hussain, Nonlinear Anal. 73 (2010), 3123–3129]. Then we prove several fixed and periodic point theorems in cone metric type spaces. c 2014 All rights reserved.

In this work, we prove a common fixed point theorem by using the generalized distance in a cone metric space. Our theorem extend some results of Abbas and Jungck [M. Abbas, G. Jungck, Common fixed point results for non-commuting mappings without continuity in cone metric spaces, J. Math. Anal. Appl. 341 (2008) 416-420] and Cho et al. [Y.J. Cho, R....

In the current work, we obtain the general solution of the following generalized cubic functional equation $$\begin{aligned}&f(x+my)+f(x-my)\\&\quad =2\left( 2\cos \left( \frac{m\pi }{2}\right) +m^2-1\right) f(x)-\frac{1}{2}\left( \cos \left( \frac{m\pi }{2}\right) +m^2-1\right) f(2x)\\&\qquad +m^2\{f(x+y)+f(x-y)\} \end{aligned}$$ for an integer...

In this paper we consider some new definitions about quadrupled fixed point in abstract metric spaces and obtain some new fixed point results in this field. These results unify, extend and generalize well-known comparable results in the existing literature. We also provide some examples and applications to support our results.

Recently, Filipovic et al. [M. Filipovic, L. Paunovic, S. Radenovic, M. Rajovic, Remarks on "Cone metric spaces and fixed point theorems of T-Kannan and T-Chatterjea contractive mappings", Math. Comput. Modelling. 54 (2011) 1467-1472] proved several fixed and periodic point theorems for solid cones on cone metric spaces. In this paper several fixed...

In this paper we consider cone metric type spaces which are introduced as a generalization of symmetric and metric spaces by M. A. Khamsi and N. Hussain [Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 73, 3123–3129 (2010; Zbl 05782234)]. Then we prove several common fixed points for weakly compatible mappings in cone metric type spac...

In this paper, the existence and uniqueness of solution of the periodic first-order fuzzy differential equation with boundary value using fixed point theorem are discussed. To do these, Minimal and maximal solutions are defined and some theorems are proved in detail.

In this paper, we characterize the function space and � -space of the [topological] tensor product of [topological] semigroups. As a consequence, for arbitrary [topological] groups and �, it will be shown that × � is an extension of ⊗� � by a proper normal subgroup N i,e. ⊗� � = �× � . Keywords: To

In this paper we develop the orthogonal projections and e-projections in Banach algebras. We prove some necessary and sufficient conditions for them and their spectrums. We also show that the sum of two generalized orthogonal pro-jections and v is a generalized orthogonal projection if, . Our results generalize the results obtained for bounded line...

Let be topological inverse semigroup and be the topological maximal subgroup of S. Following Munn [12], we have. In this paper we characterize the universal-compactification of relative to the universal-compactification of. As a consequence, we give some interesting results as. MSC(2000): Primary 43A15 ; Secondary 43A60.

In this paper, we characterize the function space and -space of the [topological] tensor product of [topological] semigroups. As a consequence, for arbitrary [topological] groups and , it will be shown that is an extension of by a proper normal subgroup N i,e. .

In this paper, the fuzzy solution of non-linear fuzzy Volterra integro-differential equation (NFIDE) is approximated. To do this, we define a sequence of fuzzy functions which approximate the fuzzy solution of this type of equations and finally, we estimate upper bound of the error.

In this paper we give a counter example for one of the lemmas of the paper" Frame of subspace in Wavelets, frames and operator theory" by P.G. Casazza and G. Kutyniok .

Recently, it has been obtained a lot of results on hyperconvex spaces, for example see [1, 2, 3, 5]. In this paper, we develop some of those results for modular hyperconvex space.