We present a lower bound on the independence number of arbitrary hypergraphs in terms of the degree vectors. The degree vector of a vertex v is given by d is the number of edges of size m containing v. We define a function f with the property that any hypergraph H = (V, E) satisfies ฮฑ(H) โฅ vโV f (d
On the cyclomatic number of a hypergraph
โ Scribed by B.D. Acharya
- Publisher
- Elsevier Science
- Year
- 1979
- Tongue
- English
- Weight
- 572 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
This note generalizes the notion of cyclomatic number (or cycle rank) from Graph Theory to
Hypergraph Theory and links it up with the concept of planarity in hypergraphs which was recently introducea by R.P. Jones. Sharp bounds are obtained for the cyclomatic number of the planar hypergraphs and, further, it is shown that the upper bound is attainable if, ?nd only if the hypergraph satisfies Krewera's condition.
๐ SIMILAR VOLUMES
For a pair of integers 1 F โฅr, the โฅ-chromatic number of an r-uniform ลฝ . hypergraph H s V, E is the minimal k, for which there exists a partition of V into subsets < < T, . . . , T such that e l T F โฅ for every e g E. In this paper we determine the asymptotic 1 k i ลฝ . behavior of the โฅ-chromatic n
Soit H = (X. ~1 un hypergraphe h-uniforme avec IX] = net soit L h ~(H! le graphe Jont les sommets reprdsentent les arates de H, deux sommets 6lant reli6s si et seulement si t~s z~r6tes qu'ils reprdsen!ent intersectent en h -1 sommet,=. Nous montrons que sif,, t(H) ne contienl pas de cycle, alors I~[
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## Abstract The ErdลsโRรฉnyi and Projective Norm graphs are algebraically defined graphs that have proved useful in supplying constructions in extremal graph theory and Ramsey theory. Their eigenvalues have been computed and this yields an upper bound on their independence number. Here we show that
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