Journal of Mathematical Analysis and Applications ( IF 1.3 ) Pub Date : 2021-04-16 , DOI: 10.1016/j.jmaa.2021.125236 A. Amini-Harandi , M. Fakhar , H.R. Hajisharifi
In this paper, we first obtain a characterization of transfer weakly lower continuous functions. Then, by introducing the class of nearly quasi-closed set-valued mappings, we obtain some characterizations of set-valued mappings whose displacement functions are transfer weakly lower continuous. We also present some fixed point theorems for nearly quasi-closed set-valued mappings which are either nearly almost convex or almost affine. Finally, we construct an almost affine mapping , which is not α-almost convex for any continuous and strictly increasing function with . This example gives an affirmative response to the Question 3 of Jachymski (2015) [8].
中文翻译:
近似准封闭和近似凸映射的不动点
在本文中,我们首先获得传递弱的连续函数的刻画。然后,通过介绍几乎准封闭的集值映射的类,我们获得了位移函数以弱弱连续传递的集值映射的一些特征。我们还为近似准闭集值映射提供了一些不动点定理,它们几乎是凸的或仿射的。最后,我们构建了一个近似仿射的映射,对于任何连续且严格增加的函数,它不是α-几乎凸的 和 。该示例对Jachymski(2015)的问题3给出了肯定的回答[8]。