Let C be a compact convex subset of a Hausdorff topological vector space (E , τ) and σ another Hausdorff vector topology in E . We establish an approximate fixed point result for sequentially continuous maps f : (C , σ) → (C , τ). As application, we obtain the weakapproximate fixed point property for demicontinuous self-mapping weakly compact convex sets in general Banach spaces and use this to...

Let X be a linear space. A p-norm on X is a real-valued function on X with 0 < p ≤ 1, satisfying the following conditions: (i) ‖x‖p ≥ 0 and ‖x‖p = 0⇔ x = 0, (ii) ‖αx‖p = |α|p‖x‖p, (iii) ‖x+ y‖p ≤ ‖x‖p +‖y‖p for all x, y ∈ X and all scalars α. The pair (X ,‖,‖p) is called a p-normed space. It is a metric linear space with a translation invariant metric dp defined by dp(x, y)= ‖x− y‖p for all x, ...

A subset M of a topological space 5 is said to have a convex metric (even though S may have no metric) if the subspace M of 5 has a convex metric. It is known [5 J that a compact continuum is locally connected if it has a convex metric. The question has been raised [5] as to whether or not a compact locally connected continuum M can be assigned a convex metric. Menger showed [5] that M is conve...

In [1,2,3], A. C. Baker and J.W. Baker studied the subspace Ma(S) of the convolution measure algebra M, (S) of a locally compact semigroup. H. Dzinotyiweyi in [5,7] considers an analogous measure space on a large class of C-distinguished topological semigroups containing all completely regular topological semigroups. In this paper, we extend the definitions to study the weighted semigroup ...

It follows from Browder (Summa Bras Math 4:183–191, 1960) that for every continuous function $$F : (X \times Y) \rightarrow Y$$ , where X is the unit interval and Y a nonempty, convex, compact subset of locally convex linear vector space, set fixed points F, defined by $$C_F := \{ (x,y) \in :F(x,y)=y\}$$ has connected component whose projection to first coordinate X. We extend Browder’s result ...

In this paper, we study a general minimization vector problem which is expressed in terms of perturbation mapping defined on product locally convex Hausdorff topological spaces with values another space. Several representations the epigraph conjugate are given, and then, variants Farkas lemmas associated system by established. A dual so-called loose mentioned stable strong duality results betwe...

This paper provides KKT and saddle point optimality conditions, duality theorems and stability theorems for consistent convex optimization problems posed in locally convex topological vector spaces. The feasible sets of these optimization problems are formed by those elements of a given closed convex set which satisfy a (possibly in…nite) convex system. Moreover, all the involved functions are ...

From a fixed point theorem for compact acyclic maps defined on admissible convex sets in the sense of Klee, we first deduce collectively fixed point theorems, intersection theorems for sets with convex sections, and quasi-equilibrium theorems. These quasi-equilibrium theorems are applied to give simple and unified proofs of the known variational inequalities of the Hartman-Stampacchia-Browder t...

‎The aim of this paper is to establish the equivalence between the concepts‎ ‎of an $S$-metric space and a cone $S$-metric space using some topological‎ ‎approaches‎. ‎We introduce a new notion of a $TVS$-cone $S$-metric space using‎ ‎some facts about topological vector spaces‎. ‎We see that the known results on‎ ‎cone $S$-metric spaces (or $N$-cone metric spaces) can be directly obtained‎ from...

This paper provides some useful results for convex risk measures. In fact, we consider convex functions on a locally convex vector space E which are monotone with respect to the preference relation implied by some convex cone and invariant with respect to some numeraire (“cash”). As a main result, for any function f , we find the greatest closed convex monotone and cash-invariant function major...