Nullspace embeddings for outerplanar graphs

The Matching Book Embedding of Biconnected Outerplanar Graphs

The $n$-$book ~embedding$ of a graph $G$ is an embedding of the graph $G$ in an $n$-book with the vertices of $G$ on the spine and each edge to the pages without crossing each other. If the degree of vertices of $G$ at most one in each page, the $n$-book embedding is $matching$. The $matching~ book~ thickness$ of graph $G$ is the smallest $n$ so that $G$ can be matching embedded in an $n$-book. In this paper, the matching book thickness of the biconnected outerplanar graphs is determined.

Outerspatial 2-complexes: Extending the class of outerplanar graphs to three dimensions

We introduce the class of outerspatial 2-complexes as the natural generalisation of the class of outerplanar graphs to three dimensions. Answering a question of O-joung Kwon, we prove that a locally 2-connected 2-complex is outerspatial if and only if it does not contain a surface of positive genus as a subcomplex and does not have a space minor that is a generalised cone over $K_4$ or $K_{2,3}$. This is applied to nested plane embeddings of graphs; that is, plane embeddings constrained by conditions placed on a set of cycles of the graph.

Maximum spectral radius of outerplanar 3-uniform hypergraphs

In this paper, we study the maximum spectral radius of outerplanar $3$-uniform hypergraphs. Given a hypergraph $\mathcal{H}$, the shadow of $\mathcal{H}$ is a graph $G$ with $V(G)= V(\mathcal{H})$ and $E(G) = \{uv: uv \in h \textrm{ for some } h\in E(\mathcal{H})\}$. A graph is \textit{outerplanar} if it can be embedded in the plane such that all its vertices lie on the outer face. A $3$-uniform hypergraph $\mathcal{H}$ is called \textit{outerplanar} if its shadow has an outerplanar embedding such that every hyperedge of $\mathcal{H}$ is the vertex set of an interior triangular face of the sha…

List total coloring of pseudo-outerplanar graphs

A graph is pseudo-outerplanar if each of its blocks has an embedding in the plane so that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. It is proved that every pseudo-outerplanar graph with maximum degree Δ\geq 5 is totally (Δ+1)-choosable.

Total coloring of pseudo-outerplanar graphs

A graph is pseudo-outerplanar if each of its blocks has an embedding in the plane so that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. In this paper, the total coloring conjecture is completely confirmed for pseudo-outerplanar graphs. In particular, it is proved that the total chromatic number of every pseudo-outerplanar graph with maximum degree $Δ\geq 5$ is $Δ+1$.

极大外平面图的总弦长

The total chord length of maximal outerplanar graphs

该研究针对极大外平面图的总弦长问题，确定了n≥5时同阶图中的最小、最大总弦长对应的图，刻画了最大总弦长图的特征，并证明了最值区间内所有整数均可实现为总弦长。