Ekeland Variational Principles in Vector Equilibrium Problems
研究了最终空间为实线性空间（不一定有拓扑结构）的向量均衡问题，利用集值映射的严格不动点定理，得到了精确和近似的埃克兰变分原理，改进了文献中的相关结果。
In this paper, we focus on vector equilibrium problems whose final space is a real linear space not necessarily endowed with a topology. In this framework, some exact and approximate Ekeland variational principles are obtained. The main mathematical tool is a kind of strict fixed point theorem for set-valued mappings, from which the Ekeland variational principles are derived by means of algebraic notions and a concept of approximate solution for vector equilibrium problems based on free-disposal sets. The obtained results improve other recent ones of the literature, and clarify the role of some assumptions usually required on the vector bifunction to state Ekeland variational principles in vector equilibrium problems.