منابع مشابه
Average Degree-Eccentricity Energy of Graphs
The concept of average degree-eccentricity matrix ADE(G) of a connected graph $G$ is introduced. Some coefficients of the characteristic polynomial of ADE(G) are obtained, as well as a bound for the eigenvalues of ADE(G). We also introduce the average degree-eccentricity graph energy and establish bounds for it.
متن کاملk-forested choosability of graphs with bounded maximum average degree
A proper vertex coloring of a simple graph is $k$-forested if the graph induced by the vertices of any two color classes is a forest with maximum degree less than $k$. A graph is $k$-forested $q$-choosable if for a given list of $q$ colors associated with each vertex $v$, there exists a $k$-forested coloring of $G$ such that each vertex receives a color from its own list. In this paper, we prov...
متن کاملRequired Growing Degree-Days (GDDs) for each Phenological Stage of Fritillaria imperialis
Studying plant phenology is very important to regulate the rangeland utilization. Plant phenology can be determined by Growing Degree Days (GDDs). Since temperature varies yearly, the phenological stages may consequently differ yearly. Determining the base temperature is one of the key steps in the calculation of GDDs. The aim of this study was to calculate the required GDDs for each phenologic...
متن کاملEvery Graph of Sufficiently Large Average Degree Contains a C4-Free Subgraph of Large Average Degree
We prove that for every k there exists d = d(k) such that every graph of average degree at least d contains a subgraph of average degree at least k and girth at least six. This settles a special case of a conjecture of Thomassen.
متن کاملLower bound of the Hadwiger number of graphs by their average degree
Let us recall the notion of the Hadwiger number. The following operations are called elementary contractions: substitution of two adjacent points vl and v~ for a new point vs connected to the points connected to v~ or v2; removal of an edge; removal of a point. The graph G is said to be contractable to the graph H if H can be obtained from G by means of a sequence of elementary contractions. Th...
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ژورنال
عنوان ژورنال: Nature
سال: 1904
ISSN: 0028-0836,1476-4687
DOI: 10.1038/070529a0