Improved lower bounds on k-independence
β Scribed by Yair Caro; Zsolt Tuza
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 418 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A vertex set Y in a (hyper)graph is called kβindependent if in the sub(hyper)βgraph induced by Y every vertex is incident to less than k edges. We prove a lower bound for the maximum cardinality of a kβindependent setβin terms of degree sequencesβwhich strengthens and generalizes several previously known results, including TurΓ‘n's theorem.
π SIMILAR VOLUMES
We investigate lower bounds on the size of K 4 -free graphs. For several ranges of independence relative to order and for graphs with maximum degree 3 and 4, we find sharp lower bounds. We also evaluate Ramsey-type numbers over the classes of graphs with maximum degree 3 and with maximum degree 4.
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 Ξ±(H) β₯ vβV f (d