Graphlets are subgraphs rooted at a fixed vertex. The number of occurrences of graphlets aligned to a particular vertex, called graphlet degree sequence (gds), gives a topological description of the surrounding of the analyzed vertex. Graphlet degree distribution (gdd) of a graph is a matrix containing graphlet degree sequence for all vertices in the given graph. A long standing open problem called reconstruction conjecture (RC) asks whether the structure of a graph is uniquely determined by the multiset of its vertex-deleted subgraphs. Graphlet degree distribution up to size (n - 1), (<= n - 1)-gdd, gives more information to reconstruct the graph and we use it to reconstruct any graph having a unique almost-asymmetric vertex-deleted subgraph, where almost-asymmetric means that at most one automorphism orbit has size larger than one. Moreover, we prove that any graph containing a vertex-cut of size 1 or any graph of order n having a vertex with degree at most 2 or at least n-2 is reconstructible from its (<= n - 1)-gdd, which expands results shown in the standard RC. We also discuss the relation between gdd and graph connectivity and the conditions on (<= 3)-gdd, whose breaking means that no graph with such gdd exists.
翻译:图元是以固定顶点为根的连通子图。与特定顶点对齐的图元出现次数,称为图元度序列(gds),提供了被分析顶点邻域的拓扑描述。图的图元度分布(gdd)是一个矩阵,包含给定图中所有顶点的图元度序列。一个长期存在的开放问题——重构猜想(RC)——探讨图的结构是否由其顶点删除子图的多重集唯一确定。规模不超过(n-1)的图元度分布(≤ n-1)-gdd 提供了更多用于重构图的信息,我们利用它来重构任何具有唯一几乎非对称顶点删除子图的图,其中“几乎非对称”指至多一个自同构轨道的大小大于一。此外,我们证明了任何包含大小为1的顶点割的图,或任何阶数为n且存在一个度数不超过2或至少为n-2的顶点的图,均可从其(≤ n-1)-gdd重构,这扩展了标准重构猜想中的已有结果。我们还讨论了gdd与图连通性之间的关系,以及(≤3)-gdd的约束条件——违反这些条件意味着不存在具有该gdd的图。