Independent Sets in Graphs with an Excluded Clique Minor
نویسنده
چکیده
Let G be a graph with n vertices, with independence number α, and with with no Kt+1-minor for some t ≥ 5. It is proved that (2α− 1)(2t − 5) ≥ 2n− 5.
منابع مشابه
Cohen-Macaulay $r$-partite graphs with minimal clique cover
In this paper, we give some necessary conditions for an $r$-partite graph such that the edge ring of the graph is Cohen-Macaulay. It is proved that if there exists a cover of an $r$-partite Cohen-Macaulay graph by disjoint cliques of size $r$, then such a cover is unique.
متن کاملIndependent sets in edge-clique graphs
We show that the edge-clique graphs of cocktail party graphs have unbounded rankwidth. This, and other observations lead us to conjecture that the edge-clique cover problem is NP-complete for cographs. We show that the independent set problem on edge-clique graphs of cographs and of distance-hereditary graphs can be solved in O(n4) time. We show that the independent set problem on edge-clique g...
متن کاملRandom graphs containing few disjoint excluded minors
The Erdős-Pósa theorem (1965) states that in each graph G which contains at most k disjoint cycles, there is a ‘blocking’ set B of at most f(k) vertices such that the graph G − B is acyclic. Robertson and Seymour (1986) give an extension concerning any minor-closed class A of graphs, as long as A does not contain all planar graphs: in each graph G which contains at most k disjoint excluded mino...
متن کاملExcluding a Countable Clique
We extend the excluded Kn minor theorem of Robertson and Seymour to infinite graphs, and deduce a structural characterization of the infinite graphs that have no Kא0 minor. The latter is a refinement of an earlier characterization of Robertson, Seymour and the second author.
متن کاملIntersection graphs associated with semigroup acts
The intersection graph $mathbb{Int}(A)$ of an $S$-act $A$ over a semigroup $S$ is an undirected simple graph whose vertices are non-trivial subacts of $A$, and two distinct vertices are adjacent if and only if they have a non-empty intersection. In this paper, we study some graph-theoretic properties of $mathbb{Int}(A)$ in connection to some algebraic properties of $A$. It is proved that the fi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete Mathematics & Theoretical Computer Science
دوره 9 شماره
صفحات -
تاریخ انتشار 2007