中文

无AT自由外平面图的B$_0$-VPG表示

组合数学 2023-03-07 v2 离散数学

摘要

k-弯路径是平面上由至多k+1k+1条轴平行线段构成的非自交折线。Bk_k-VPG是一类可表示为同一平面内k-弯路径交图的图。本文中,我们证明所有无AT自由外平面图均为B0_0-VPG,即平面上水平与垂直线段的交图。我们的证明是构造性的,并给出了该类图的多项式时间B0_0-VPG绘制算法。在一系列改进之后,Gonçalves、Isenmann与Pennarun [SODA 2018]证明了所有平面图均为B1_1-VPG。由于存在非B0_0-VPG的平面图,在平面图中刻画B0_0-VPG图变得有趣。Chaplick等人 [WG 2012] 已证明在Bk+1_{k+1}-VPG中识别Bk_k-VPG图是NP完全的。因此在B1_1-VPG中识别B0_0-VPG图一般而言是NP完全的,但限制到平面图时该问题开放。存在非B0_0-VPG的外平面图与无AT自由平面图。这激发了我们对无AT自由外平面图的兴趣。

关键词

引用

@article{arxiv.2209.08269,
  title  = {B$_0$-VPG Representation of AT-free Outerplanar Graphs},
  author = {Sparsh Jain and Sreejith K. Pallathumadam and Deepak Rajendraprasad},
  journal= {arXiv preprint arXiv:2209.08269},
  year   = {2023}
}

备注

v1: A preliminary version, which did not contain the characterization of linear outerplanar graphs (Section 3), was presented at CALDAM 2022. v2: Results and proofs unchanged; removed linear outerplanar graphs in the abstract and added the motivation of B$_0$-VPG planar problem; margin size changed; added a new figure in introduction; a slight modification in the presentation of the proposition