Lecture 5 : Forbidding Cycles
نویسنده
چکیده
The proof of Theorem 1 consists of the following two lemmas. Recall that K r is the complete r-partite graph with p vertices in each class. In other words, K r = Tr(pr), the Turán graph with pr many vertices. It is easy to see that χ(K r ) = r. Lemma 2. For all c, η > 0, n > 8/η, if G is a graph on n vertices with e(G) ≥ (c + η) ( n 2 ) , then G has a subgraph G′ with n′ ≥ 1 2 √ ηn vertices such that δ(G′) ≥ cn′.
منابع مشابه
Forbidding and enforcing on graphs
We define classes of graphs based on forbidding and enforcing boundary conditions. Forbidding conditions prevent a graph to have certain combinations of subgraphs and enforcing conditions impose certain subgraph structures.We say that a class of graphs is an fe-class if the class can be defined through forbidding and enforcing conditions (fe-system). We investigate properties of fe-systems and ...
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