Going back to the groundbreaking works by Edgeworth (1881) and Pareto (1906), the notion
of optimality in multiobjective optimization is an efficient tool for describing optimal solutions …

Two main existence conditions for solutions of variational relation problems are established
without convexity. The first one is based on a finite solvability property and the second one …

In this review, firstly, we recall Ky Fan's contributions to the KKM theory based on his
celebrated 1961 KKM lemma (or theFan-KKM theorem). Secondly, we introduce relatively …

The purpose of this paper is to present a unifying approach to study various models of
equilibrium theory and variational inclusions. A simple condition is established for the …

Hölder continuity and uniqueness of the solutions of general multivalued vector
quasiequilibrium problems in metric spaces are established. The results are shown to be …

We define a generalized KKM map**, called T-KKM map**, and the corresponding
generalized KKM property, which include many counterparts existing in the literature. KKM …

Bilevel equilibrium and optimization problems with equilibrium constraints are considered.
We propose a relaxed level closedness and use it together with pseudocontinuity …

We establish sufficient existence conditions for general quasivariational inclusion problems,
which contain most of variational inclusion problems and quasiequilibrium problems …

We extend and sharpen the result in Ait Mansour and Scrimali (J. Glob. Optim. 40: 175–184,
2008) on the Hölder continuity of the solution sets of quasivariational inequalities in Hilbert …

We introduce some definitions related to semicontinuity of multivalued map**s and
discuss various kinds of semicontinuity-related properties. Sufficient conditions for the …