中文

关于CAT(0)立方复形嵌入树乘积的研究

度量几何 2026-04-23 v4 组合数学

摘要

我们证明了最大度为Δ\Delta的二维CAT(0)立方复形X{\bf X}的接触图可以用至多ϵ(Δ)=MΔ26\epsilon(\Delta)=M\Delta^{26}种颜色着色,其中MM为固定常数。这意味着X{\bf X}(以及相关的中间图)可以等距嵌入至多ϵ(Δ)\epsilon(\Delta)棵树的笛卡尔积中,并且以X{\bf X}为域的事件结构允许一个具有ϵ(Δ)\epsilon(\Delta)个标签的优美标号。另一方面,我们给出了一个5维CAT(0)立方复形的例子,其0-立方体具有一致有界度数,但无法嵌入有限棵树的笛卡尔积中。这否定了F. Haglund、G. Niblo、M. Sageev以及本文第一作者独立提出的一个问题。

关键词

引用

@article{arxiv.1107.0863,
  title  = {On embeddings of CAT(0) cube complexes into products of trees},
  author = {Victor Chepoi and Mark F. Hagen},
  journal= {arXiv preprint arXiv:1107.0863},
  year   = {2026}
}

备注

Previous version had an error in Lemma 12, affecting Theorem 1. Current version has appendix correcting Theorem 1 under additional hypothesis: no vertex has a 5-cycle in its link or, equivalently, the crossing graph has no 5-cycle. (4-cycles, and cycles larger than 5, are allowed.) Theorem 2, is unchanged. Appendix appears as journal correction: https://doi.org/10.1016/j.jctb.2026.04.001