论文标题
Hahn-Banach用于公制功能和心脏功能
Hahn-Banach for metric functionals and horofunctions
论文作者
论文摘要
据观察，Hahn-Banach定理的自然类似物对于公制功能有效，但对于呼吸功能而言失败。证明了几种关于单个同量和1- lipschitz地图的不变度度函数的陈述。指出了与此主题相关的其他各种定义，示例和事实。特别是表明，每个无限Cayley图的度量（呼吸功能）边界至少包含两个点。
It is observed that a natural analog of the Hahn-Banach theorem is valid for metric functionals but fails for horofunctions. Several statements of the existence of invariant metric functionals for individual isometries and 1-Lipschitz maps are proved. Various other definitions, examples and facts are pointed out related to this topic. In particular it is shown that the metric (horofunction) boundary of every infinite Cayley graphs contains at least two points.
