Results 1 to 10 of about 1,769 (162)

Edge-group choosability of outerplanar and near-outerplanar graphs [PDF]

open access: yesTransactions on Combinatorics, 2020
Let $\chi_{gl}(G)$ be the {\it{group choice number}} of $G$. A graph $G$ is called {\it{edge-$k$-group choosable}} if its line graph is $k$-group choosable. The {\it{group-choice index}} of $G$, $\chi'_{gl}(G)$, is the smallest $k$ such that $G$ is edge-$
Amir Khamseh
doaj   +2 more sources

The Singularity of Oriented Outerplanar Graphs with a Given Number of Inner Edges

open access: yesJournal of Mathematics, 2022
A digraph is called oriented if there is at most one arc between two distinct vertices. An oriented graph is called nonsingular (singular) if its adjacency matrix AD is nonsingular (singular).
Borui He, Xianya Geng, Long Wang
doaj   +2 more sources

B0-VPG Representation of AT-free Outerplanar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2023
A $k$-bend path is a non-self-intersecting polyline in the plane made of at most $k+1$ axis-parallel line segments. B$_{k}$-VPG is the class of graphs which can be represented as intersection graphs of $k$-bend paths in the same plane. In this paper,
Sparsh Jain   +2 more
doaj   +1 more source

On the planarity of line Mycielskian graph of a graph

open access: yesRatio Mathematica, 2020
The line Mycielskian graph of a graph G, denoted by Lμ(G) is defined as the graph obtained from L(G) by adding q+1 new vertices E' = ei' : 1 ≤  i ≤  q and e, then for 1 ≤  i ≤  q , joining ei' to the neighbours of ei  and  to e.
Keerthi G. Mirajkar   +1 more
doaj   +1 more source

Circular Separation Dimension of a Subclass of Planar Graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2017
A pair of non-adjacent edges is said to be separated in a circular ordering of vertices, if the endpoints of the two edges do not alternate in the ordering.
Arpitha P. Bharathi   +2 more
doaj   +1 more source

On Another Class of Strongly Perfect Graphs

open access: yesMathematics, 2022
For a commutative ring R with unity, the associate ring graph, denoted by AG(R), is a simple graph with vertices as nonzero elements of R and two distinct vertices are adjacent if they are associates.
Neha Kansal   +3 more
doaj   +1 more source

On the spread of outerplanar graphs

open access: yesSpecial Matrices, 2022
The spread of a graph is the difference between the largest and most negative eigenvalue of its adjacency matrix. We show that for sufficiently large nn, the nn-vertex outerplanar graph with maximum spread is a vertex joined to a linear forest with Ω(n ...
Gotshall Daniel   +2 more
doaj   +1 more source

Irreducible nonmetrizable path systems in graphs

open access: yesJournal of Graph Theory, Volume 102, Issue 1, Page 5-14, January 2023., 2023
Abstract A path system P ${\mathscr{P}}$ in a graph G =(V , E ) $G=(V,E)$ is a collection of paths with a unique u v $uv$ path for every two vertices u , v ∈ V $u,v\in V$. We say that P ${\mathscr{P}}$ is consistent if for any path P ∈ P $P\in {\mathscr{P}}$, every subpath of P $P$ is also in P ${\mathscr{P}}$.
Daniel Cizma, Nati Linial
wiley   +1 more source

Longest and shortest cycles in random planar graphs

open access: yesRandom Structures &Algorithms, Volume 60, Issue 3, Page 462-505, May 2022., 2022
Abstract Let be a graph chosen uniformly at random from the class of all planar graphs on vertex set with edges. We study the cycle and block structure of when . More precisely, we determine the asymptotic order of the length of the longest and shortest cycle in in the critical range when .
Mihyun Kang, Michael Missethan
wiley   +1 more source

Monotonic Representations of Outerplanar Graphs as Edge Intersection Graphs of Paths on a Grid

open access: yesJournal of Graph Algorithms and Applications, 2022
In a representation of a graph $G$ as an edge intersection graph of paths on a grid (EPG) every vertex of $G$ is represented by a path on a grid and two paths share a grid edge iff the corresponding vertices are adjacent.
Eranda Çela, Elisabeth Gaar
doaj   +1 more source

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