Forbidding induced even cycles in a graph: Typical structure and counting

نویسندگان
چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

a typical graph structure of a ring

the zero-divisor graph of a commutative ring r with respect to nilpotent elements is a simple undirected graph $gamma_n^*(r)$ with vertex set z_n(r)*, and two vertices x and y are adjacent if and only if xy is nilpotent and xy is nonzero, where z_n(r)={x in r: xy is nilpotent, for some y in r^*}. in this paper, we investigate the basic properties of $gamma_n^*(r)$. we discuss when it will be eu...

متن کامل

Even Cycles and Even 2-Factors in the Line Graph of a Simple Graph

Let G be a connected graph with an even number of edges. We show that if the subgraph of G induced by the vertices of odd degree has a perfect matching, then the line graph of G has a 2-factor whose connected components are cycles of even length (an even 2-factor). For a cubic graph G, we also give a necessary and sufficient condition so that the corresponding line graph L(G) has an even cycle ...

متن کامل

Lecture 5 : Forbidding Cycles

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 suc...

متن کامل

Forbidding Hamilton cycles in uniform hypergraphs

For 1 ≤ d ≤ ` < k, we give a new lower bound for the minimum d-degree threshold that guarantees a Hamilton `-cycle in k-uniform hypergraphs. When k ≥ 4 and d < ` = k − 1, this bound is larger than the conjectured minimum d-degree threshold for perfect matchings and thus disproves a wellknown conjecture of Rödl and Ruciński. Our (simple) construction generalizes a construction of Katona and Kier...

متن کامل

WORM colorings Forbidding Cycles or Cliques

Given a coloring of the vertices, we say subgraph H is monochromatic if every vertex of H is assigned the same color, and rainbow if no pair of vertices of H are assigned the same color. Given a graph G and a forbidden graph F , we define an F -WORM coloring of G as a coloring of the vertices if G without a rainbow or monochromatic subgraph isomorphic to F . We explore such colorings especially...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Combinatorial Theory, Series B

سال: 2018

ISSN: 0095-8956

DOI: 10.1016/j.jctb.2018.02.002