Results 31 to 40 of about 31,664 (169)

Triangle-free graphs which are minimal for some nonstable 4-vertex subset

open access: yesArab Journal of Mathematical Sciences, 2015
In a graph G, a module is a vertex subset M such that every vertex outside M is adjacent to all or none of M. A graph G is prime if ϕ, the single-vertex sets, and V(G) are the only modules in G.
Mohammad Alzohairi
doaj   +1 more source

Colored complete hypergraphs containing no rainbow Berge triangles

open access: yesTheory and Applications of Graphs, 2019
The study of graph Ramsey numbers within restricted colorings, in particular forbidding a rainbow triangle, has recently been blossoming under the name Gallai-Ramsey numbers.
Colton Magnant
doaj   +1 more source

Laplacian Spectral Properties of Signed Circular Caterpillars

open access: yesTheory and Applications of Graphs, 2020
A circular caterpillar of girth $n$ is a graph such that the removal of all pendant vertices yields a cycle $C_n$ of order $n$. A signed graph is a pair $\Gamma=(G, \sigma)$, where $G$ is a simple graph and $\sigma: E(G) \rightarrow \{+1, -1\}$ is the ...
Maurizio Brunetti
doaj   +1 more source

Decomposing Graphs into Edges and Triangles [PDF]

open access: yesCombinatorics, Probability and Computing, 2019
We prove the following 30 year-old conjecture of Győri and Tuza: the edges of every n-vertex graph G can be decomposed into complete graphs C1,. . .,Cℓ of orders two and three such that |C1|+···+|Cℓ| ≤ (1/2+o(1))n2. This result implies the asymptotic version of the old result of Erdős, Goodman and Pósa that asserts the existence of such a decomposition
Daniel Král'   +3 more
openaire   +4 more sources

On the Circumference of 3-Connected Cubic Triangle-Free Plane Graphs

open access: yesJournal of Mathematics, 2021
The circumference of a graph G is the length of a longest cycle in G, denoted by cirG. For any even number n, let cn  = min {cirG|G is a 3-connected cubic triangle-free plane graph with n vertices}. In this paper, we show that an upper bound of cn is n+1−
Adthasit Sinna   +2 more
doaj   +1 more source

Packing Triangles in Weighted Graphs [PDF]

open access: yesSIAM Journal on Discrete Mathematics, 2014
v2: 20 pages, corrected version (from 2013) following referee ...
Chapuy, Guillaume   +4 more
openaire   +2 more sources

Simplifying social networks via triangle-based cohesive subgraphs

open access: yesVisual Informatics, 2023
One main challenge for simplifying node-link diagrams of large-scale social networks lies in that simplified graphs generally contain dense subgroups or cohesive subgraphs.
Rusheng Pan   +6 more
doaj   +1 more source

Straight-Line Triangle Representations via Schnyder Labelings

open access: yesJournal of Graph Algorithms and Applications, 2015
A straight-line triangle representation (SLTR) of a planar graph is a straight-line drawing such that all the faces including the outer face are triangles. Such a drawing can be viewed as a tiling of a triangle with triangles where the input graph is the
Nieke Aerts, Stefan Felsner
doaj   +1 more source

Triangle-degree and triangle-distinct graphs

open access: yesDiscrete Mathematics
Let $G$ be a simple graph and $v$ be a vertex of $G$. The triangle-degree of $v$ in $G$ is the number of triangles that contain $v$. While every graph has at least two vertices with the same degree, there are graphs in which every vertex has a distinct triangle-degree. In this paper, we construct an infinite family of graphs with this property. We also
Zhanar Berikkyzy   +7 more
openaire   +3 more sources

Edge Bounds and Degeneracy of Triangle-Free Penny Graphs and Squaregraphs

open access: yesJournal of Graph Algorithms and Applications, 2018
We show that triangle-free penny graphs have degeneracy at most two, and that both triangle-free penny graphs and squaregraphs have at most $\min\bigl(2n-\Omega(\sqrt n),2n-D-2\bigr)$ edges, where $n$ is the number of vertices and $D$ is the diameter of ...
David Eppstein
doaj   +1 more source

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