桥三剖分诱导的三次图
Cubic graphs induced by bridge trisections
AI总结:
本文证明每个 Tait 着色的三次图均可作为桥三剖分的1-骨架,实现不打结曲面,并推广至不可定向情形,为三平面图转换提供新方法。
摘要:
4-球面中的每个嵌入曲面 $\mathcal{K}$ 都承认一个桥三剖分,即将 $(S^4,\mathcal{K})$ 分解为三个简单部分。在这种情况下,曲面 $\mathcal{K}$ 由一个嵌入的1-复形决定,该复形称为桥三剖分的 $\textit{1-骨架}$。作为抽象图,1-骨架是一个三次图 $Γ$,它继承了一个自然的 Tait 着色,即对 $Γ$ 的边集进行3-着色,使得每个顶点关联所有三种颜色的边。本文反转了这一关联:我们证明每个 Tait 着色的三次图都同构于对应于一个不打结曲面的桥三剖分的1-骨架。当曲面不可定向时,我们证明对于每个可能的正常欧拉数,这样的嵌入都存在。作为推论,每个打结曲面的三平面图都可以通过交叉变化和内部 Reidemeister 移动转换为不打结曲面的三平面图。
英文摘要:
Every embedded surface $\mathcal{K}$ in the 4-sphere admits a bridge trisection, a decomposition of $(S^4,\mathcal{K})$ into three simple pieces. In this case, the surface $\mathcal{K}$ is determined by an embedded 1-complex, called the $\textit{1-skeleton}$ of the bridge trisection. As an abstract graph, the 1-skeleton is a cubic graph $Γ$ that inherits a natural Tait coloring, a 3-coloring of the edge set of $Γ$ such that each vertex is incident to edges of all three colors. In this paper, we reverse this association: We prove that every Tait-colored cubic graph is isomorphic to the 1-skeleton of a bridge trisection corresponding to an unknotted surface. When the surface is nonorientable, we show that such an embedding exists for every possible normal Euler number. As a corollary, every tri-plane diagram for a knotted surface can be converted to a tri-plane diagram for an unknotted surface via crossing changes and interior Reidemeister moves.
机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。