论文标题
Digraphs I的末端：基本理论
Ends of digraphs I: basic theory
论文作者
论文摘要
在一系列三篇论文中，我们为有向图开发了最终空间理论。至于无方向的图，挖掘的末端是无穷大的点，其射线会收敛。与无方向的图不同，有些末端由极限边缘连接；这些对于获得有限收缩未成年人的天然（自然（反）极限，这些杂物的末端空间至关重要。作为我们系列的第一篇论文的主要结果，我们表明，无向图的方向的概念（缠结的末端描述）扩展到了挖掘物：挖掘图及其末端的“方向”之间有一对一的对应关系。在此过程中，我们扩展到挖掘图的许多基本工具和技术，用于研究图的末端，例如Star-Comb Lemma和Schmidt的Rayless Graphs排名。
In a series of three papers we develop an end space theory for directed graphs. As for undirected graphs, the ends of a digraph are points at infinity to which its rays converge. Unlike for undirected graphs, some ends are joined by limit edges; these are crucial for obtaining the end space of a digraph as a natural (inverse) limit of its finite contraction minors. As our main result in this first paper of our series we show that the notion of directions of an undirected graph, a tangle-like description of its ends, extends to digraphs: there is a one-to-one correspondence between the `directions' of a digraph and its ends and limit edges. In the course of this we extend to digraphs a number of fundamental tools and techniques for the study of ends of graphs, such as the star-comb lemma and Schmidt's ranking of rayless graphs.
