Symmetric Vector Quasi-equilibrium Problems Research Articles

Technical note on the existence of solutions for generalized symmetric set-valued quasi-equilibrium problems utilizing improvement set

In this paper, we establish some existence results for the solution of the generalized symmetric set-valued quasi-equilibrium problem (GSSQEP). The new forms of GSSQEP via improvement set and scalar generalized symmetric set-valued quasi-equilibrium problem (GSSQEP for short) are also introduced. By using Kakutani–Fan–Glicksberg fixed point method, maximal element principle and nonlinear scalarization technique, we develop two classes of sufficient conditions for the existence of solutions to GSSQEP. The drawback of some existing work for this problem is overcome. Moreover, some applications to the symmetric set-valued equilibrium problem (SSEP), symmetric vector quasi-equilibrium problem (SVQEP) and the set-valued equilibrium problem (SEP) are also given in this paper. Our results improve a few existing ones in Fakhar and Zafarani [Generalized symmetric vector quasiequilibrium problems. J Optim Theory Appl. 2008;136:397–409], Farajzadeh et al. [On the existence of solutions of symmetric vector equilibrium problems via nonlinear scalarization. Bull Iran Math Soc. 2019;45:35–58], Fu [Symmetric vector quasi-equilibrium problems. J Math Anal Appl. 2003;285:708–713], Han et al. [Existence of solutions for symmetric vector set-valued quasi-equilibrium problems with applications. Pacific J Optim. 2018;14:31–49].

Existence conditions for symmetric strong vector quasi-equilibrium problems

In the following paper, the symmetric strong vector quasi-equilibrium problems will be studied thoroughly. Afterward, the existence conditions of solution sets for these problems has been established. The results which are presented in this paper improve and extend the main results mentioned in the literature. Our results can be illustrated by some interesting examples. In 1994, Noor and Oettli introduced the following the symmetric scalar quasi-equilibrium problem. This problem is one of the generalization of the symmetric scalar quasi-equilibrium problem which is presented by Noor and Oettli. Since then, the symmetric vector quasi-equilibrium problem has been investigated by a huge number of authors in different ways. The research works mentioned above are one of our motivation to improve and extend the problem. So, in this paper, we will introduce the vector quasi-equilibrium problems. Afterward, some existence conditions of solution sets for these problems will be established. The symmetric vector quasi-equilibrium problems consist of many optimization - related models namely symmetric vector quasi-variational inequality problems, fixed point problems, coincidence-point problems and complementarity problems, etc. In recent years, a lot of results for existence of solutions for symmetric vector quasi-equilibrium problems, vector quasi-equilibrium problems, vector quasivariational inequality problems and optimization problems have been established by many authors in different ways. We will present our work in the following steps. In the first section of our paper, we will introduce the model of symmetric vector quasi-equilibrium problems. In the following section, we recall definitions, lemmas which can be used for the main results. In the last section, we will establish some conditions for existence and closedness of the solutions set by applying fixed-point theorem for symmetric vector quasi-equilibrium problems. The results presented in this paper improve and extend the main results in the literature. Some examples are given to illustrate our results. Hence our results, Theorem 3.1 and Theorem 3.6 have significant improvements.

Existence of solutions for generalized symmetric vector quasi-equilibrium problems in abstract convex spaces with applications

Existence of solutions for generalized symmetric vector quasi-equilibrium problems in abstract convex spaces with applications

Well-posed symmetric vector quasi-equilibrium problems

In this paper, we consider well-posedness of symmetric vector quasi-equilibrium problems. Based on a nonlinear scalarization technique, we first establish the bounded rationality model M for symmetric vector quasi-equilibrium problems, and then introduce a well-posedness concept for symmetric vector quasi-equilibrium problems, which unifies its Hadamard and Tykhonov well-posedness. Finally, sufficient conditions on the well-posedness for symmetric vector quasi-equilibrium problems are given.

Generalized Well-Posedness for Symmetric Vector Quasi-Equilibrium Problems

We introduce and study well-posedness in connection with the symmetric vector quasi-equilibrium problem, which unifies its Hadamard and Levitin-Polyak well-posedness. Using the nonlinear scalarization function, we give some sufficient conditions to guarantee the existence of well-posedness for the symmetric vector quasi-equilibrium problem.

The existence and stability of solutions for symmetric generalized quasi-variational inclusion problems

In this paper, we study the symmetric generalized quasi-variational inclusion problems. Then, we establish some existence theorems of solution sets for these problems. Moreover, the stability of solutions for these problems are also onbtained. Finally, we apply these results to symmetric vector quasi-equilibrium problems. The results presented in this paper improve and extend the main results in the literature. Some examples are given to illustrate our results.

Levitin–Polyak well-posedness of symmetric vector quasi-equilibrium problems

In this paper, we introduce generalized Levitin–Polyak well-posedness of symmetric strong vector quasi-equilibrium problem. We give characterizations for generalized Levitin–Polyak well-posedness of the symmetric strong vector quasi-equilibrium problem and the symmetric weak vector quasi-equilibrium problem by closed graph of the approximating solution mapping. Our results improve the main result presented in Zhang.

Existence and Well-Posedness for Symmetric Vector Quasi-Equilibrium Problems

An existence result for the solution set of symmetric vector quasi-equilibrium problems that allows for discontinuities is obtained. Moreover, sufficient conditions for the generalized Levitin-Polyak well-posedness of symmetric vector quasi-equilibrium problems are established.

Existence and Stability of Solutions for Generalized Symmetric Strong Vector Quasi-equilibrium Problems

In this paper, a class of generalized symmetric strong vector quasi-equilibrium problems in real locally convex Hausdorff topological vector spaces is studied. By using the Kakutani-Fan-Glicksberg fixed point theorem, an existence theorem of solutions for the generalized symmetric strong vector quasi-equilibrium problems is obtained. Moreover, the closedness of the solution set and a stability result of solutions for such problem are also derived

Well-posedness for convex symmetric vector quasi-equilibrium problems

In this paper, the notion of a generalized Levitin–Polyak well-posedness is defined for symmetric vector quasi-equilibrium problems. Sufficient conditions are given for the generalized Levitin–Polyak well-posedness. Moreover, it is shown that the results can be refined in the convex case.

Symmetric strong vector quasiequilibrium problems in Hausdorff locally convex spaces

Abstract In this article, a new symmetric strong vector quasiequilibrium problem in real locally convex Hausdorff topological vector spaces is introduced and studied. An existence theorem of solutions for the symmetric strong vector quasiequilibrium problem by using Kakutani-Fan-Glicksberg fixed point theorem is obtained. Moreover, the closedness of the solution set for this problem is derived. The results presented in this article improve and extend some known results according to Long et al. [Math. Comput. Model. 47, 445-451 (2008)], Somyot and Kanokwan [Fixed Point Theory Appl. doi:10.1155/2011/475121], and Wang et al. [Bull. Malays. Math. Sci. Soc. http://www.emis.de/journals/BMMSS/pdf/acceptedpapers/2009-11-022_R1.pdf]. 2000 MSC: 49J40; 90C29.

Various kinds of semicontinuity and the solution sets of parametric multivalued symmetric vector quasiequilibrium problems

We introduce some definitions related to semicontinuity of multivalued mappings and discuss various kinds of semicontinuity-related properties. Sufficient conditions for the solution sets of parametric multivalued symmetric vector quasiequilibrium problems to have these properties are established. Comparisons of the solution sets of our two problems are also provided. As an example of applications of our main results, the mentioned semicontinuity-related properties of the solution sets to a lower and upper bounded quasiequilibrium problem are obtained as consequences.

Generalized Symmetric Vector Quasiequilibrium Problems

We establish an existence result for scalar quasiequilibrium problems without any continuity requirement on noncompact subsets of locally convex topological vector spaces. As a consequence, we obtain a solution of symmetric scalar quasiequilibrium problem. Moreover, using a so-called nonlinear scalarization function, existence theorems for vector quasiequilibrium problems and general symmetric vector quasiequilibrium problems are obtained.

The Stability of Set of Solutions for Symmetric Vector Quasi-Equilibrium Problems

In this paper, the stability of the set of solutions for symmetric vector quasi-equilibrium problems is discussed. Then, we prove a generic stability theorem and give an existence theorem for essentially connected components of the set of solutions for symmetric vector quasi-equilibrium problems. Finally, we apply these results to vector weak saddle point problems with constraints.

Symmetric strong vector quasi-equilibrium problems

In this paper, we introduce the symmetric strong vector quasi-equilibrium problem. We then demonstrate that the symmetric strong vector quasi-equilibrium problem is solvable under the suitable assumptions. As an application, we get an existence theorem of the strong saddle points of vector-valued functions. In addition, we give a characterization of vector-valued properly quasi-convex functions.

On the symmetric vector quasi-equilibrium problems

In this paper we, using a particular technique, consider the symmetric vector quasi-equilibrium problems in the Hausdorff topological vector space. As applications of our existence theorem, a coincidence point theorem and the existence of vector optimization problem for a pair of vector-valued mappings are obtained. Moreover, we answer an open question raised by Fu in [J.Y. Fu, Symmetric vector quasi-equilibrium problems, J. Math. Anal. Appl. 285 (2003) 708–713].

Symmetric vector quasi-equilibrium problems

The symmetric vector quasi-equilibrium problem is introduced. Under suitable assumptions, the symmetric vector quasi-equilibrium problem is solvable. As its applications, a coincidence point theorem and the existence of vector optimization problem for a pair of vector-valued mappings are reduced.