Results 81 to 90 of about 1,022,735 (236)

Independent Roman Domination Stable and Vertex-Critical Graphs

open access: yesIEEE Access, 2018
A Roman dominating function (RDF) on a graph $G$ is a function $f: V(G) \rightarrow \{0, 1, 2\}$ for which every vertex assigned 0 is adjacent to a vertex assigned 2. The weight of an RDF is the value $\omega (f) = \sum _{u \in V(G)}f(u)$ .
Pu Wu   +5 more
doaj   +1 more source

Ising spin glass models versus Ising models: an effective mapping at high temperature III. Rigorous formulation and detailed proof for general graphs

open access: yes, 2007
Recently, it has been shown that, when the dimension of a graph turns out to be infinite dimensional in a broad sense, the upper critical surface and the corresponding critical behavior of an arbitrary Ising spin glass model defined over such a graph ...
Baxter R J   +13 more
core   +1 more source

Exponent-critical primitive graphs and the Kronecker product

open access: yesElectronic Journal of Graph Theory and Applications, 2019
A directed graph is primitive of exponent t if it contains walks of length t between all pairs of vertices, and t is minimal with this property. Moreover, it is exponent-critical if the deletion of any arc results in an imprimitive graph or in a ...
Olga O'Mahony, Rachel Quinlan
doaj   +1 more source

A Note on Near-factor-critical Graphs [PDF]

open access: yes, 2014
A near-factor of a finite simple graph $G$ is a matching that saturates all vertices except one. A graph $G$ is said to be near-factor-critical if the deletion of any vertex from $G$ results in a subgraph that has a near-factor. We prove that a connected
Huang, Kuo-Ching, Lih, Ko-Wei
core  

Critical percolation on certain non-unimodular graphs [PDF]

open access: yes, 2005
An important conjecture in percolation theory is that almost surely no infinite cluster exists in critical percolation on any transitive graph for which the critical probability is less than 1. Earlier work has established this for the amenable cases Z^2
Peres, Yuval   +2 more
core   +5 more sources

Mixing time of near-critical random graphs

open access: yes, 2012
Let $\mathcal{C}_1$ be the largest component of the Erd\H{o}s--R\'{e}nyi random graph $\mathcal{G}(n,p)$. The mixing time of random walk on $\mathcal {C}_1$ in the strictly supercritical regime, $p=c/n$ with fixed $c>1$, was shown to have order $\log^2n$
Ding, Jian, Lubetzky, Eyal, Peres, Yuval
core   +1 more source

New Results on Minimal Strongly Imperfect Graphs [PDF]

open access: yesScientific Annals of Computer Science, 2008
The characterization of strongly perfect graphs by a restricted list of forbidden induced subgraphs has remained an open question for a long time. The minimal strongly imperfect graphs which are simultaneous imperfect are only odd holes and odd antiholes
V. Anastasoaei, E. Olaru
doaj  

Cyclic Critical Groups of Graphs

open access: yes, 2016
In this note, we describe a construction that leads to families of graphs whose critical groups are cyclic. For some of these families we are able to give a formula for the number of spanning trees of the graph, which then determines the group ...
Becker, Ryan P., Glass, Darren B.
core  

Factor-Critical Property in 3-Dominating-Critical Graphs

open access: yes, 2006
A vertex subset $S$ of a graph $G$ is a dominating set if every vertex of $G$ either belongs to $S$ or is adjacent to a vertex of $S$. The cardinality of a smallest dominating set is called the dominating number of $G$ and is denoted by $\gamma(G)$.
Wang, Tao, Yu, Qinglin
core  

Quadratic maps with a periodic critical point of period 2 [PDF]

open access: yes, 2015
We provide a complete classification of possible graphs of rational preperiodic points of endomorphisms of the projective line of degree 2 defined over the rationals with a rational periodic critical point of period 2, under the assumption that these ...
Canci, J. K., Vishkautsan, Solomon
core   +1 more source

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