论文标题
无三角形图的重建和边缘重建
Reconstruction and Edge Reconstruction of Triangle-free Graphs
论文作者
论文摘要
由于凯利和乌拉姆而引起的重建猜想指出,每个具有至少3个顶点的图都由其子图的多键$ \ {g-v:v \ in V(g)\} $确定。令$ diam(g)$和$κ(g)$分别表示直径和图$ g $的直径和连接性,让$ \ mathcal {g} _2 _2:= \ {g:\ textrm {diam {diam}(g)(g)= 2 \} $和和$ \ MATHCAL {G} _3:= \ {g:\ textrm {diam}(g)= \ textrm {diam}(\ overline {g})= 3 \} $。众所周知,重建的猜想是正确的,并且仅当$ \ Mathcal {g} _2 \ cup \ mathcal {g} _3 $中的每2个连接图是正确的。 Balakumar和Monikandan表明,重建的猜想适用于$ \ Mathcal {g} _2 \ Cup \ Mathcal {G} _3 $,带有$κ(g)= 2 $。此外,他们询问结果是否仍然保持$κ(g)\ ge 3 $。 (如果是的,那么对于求解重建构的至关重要的图表仅限于$ \ Mathcal {g} _2 \ cup \ cup \ Mathcal {g} _3 $中包含三角形的2个连接图。 $ \ MATHCAL {G} _3 $和每个三角形的图形$ g $ in $ \ MATHCAL {g} _2 $ at $κ(g)= 3 $。我们还证明了有关边缘重建猜想的相似结果。
The Reconstruction Conjecture due to Kelly and Ulam states that every graph with at least 3 vertices is uniquely determined by its multiset of subgraphs $\{G-v: v\in V(G)\}$. Let $diam(G)$ and $κ(G)$ denote the diameter and the connectivity of a graph $G$, respectively, and let $\mathcal{G}_2:=\{G: \textrm{diam}(G)=2\}$ and $\mathcal{G}_3:=\{G:\textrm{diam}(G)=\textrm{diam}(\overline{G})=3\}$. It is known that the Reconstruction Conjecture is true if and only if it is true for every 2-connected graph in $\mathcal{G}_2\cup \mathcal{G}_3$. Balakumar and Monikandan showed that the Reconstruction Conjecture holds for every triangle-free graph $G$ in $\mathcal{G}_2\cup \mathcal{G}_3$ with $κ(G)=2$. Moreover, they asked whether the result still holds if $κ(G)\ge 3$. (If yes, the class of graphs critical for solving the Reconstruction Conjecture is restricted to 2-connected graphs in $\mathcal{G}_2\cup\mathcal{G}_3$ which contain triangles.) In this paper, we give a partial solution to their question by showing that the Reconstruction Conjecture holds for every triangle-free graph $G$ in $\mathcal{G}_3$ and every triangle-free graph $G$ in $\mathcal{G}_2$ with $κ(G)=3$. We also prove similar results about the Edge Reconstruction Conjecture.