English

A more complete version of a minimax theorem

Functional Analysis 2021-04-13 v3 Optimization and Control

Abstract

In this paper, we present a more complete version of the minimax theorem established in [7]. As a consequence, we get, for instance, the following result: Let XX be a compact, not singleton subset of a normed space (E,)(E,\|\cdot\|) and let YY be a convex subset of EE such that XYX\subseteq \overline {Y}. Then, for every convex set SYS\subseteq Y dense in YY, for every upper semicontinuous bounded function γ:XR\gamma:X\to {\bf R} and for every λ>4supXγdiam(X)\lambda>{{4\sup_X|\gamma|}\over {diam(X)}}, there exists ySy^*\in S such that the function xγ(x)+λxyx\to \gamma(x)+\lambda\|x-y^*\| has at least two global maxima in XX.

Keywords

Cite

@article{arxiv.2104.00069,
  title  = {A more complete version of a minimax theorem},
  author = {Biagio Ricceri},
  journal= {arXiv preprint arXiv:2104.00069},
  year   = {2021}
}

Comments

arXiv admin note: text overlap with arXiv:1810.08957

R2 v1 2026-06-24T00:45:00.450Z