منابع مشابه
Extremal results for rooted minor problems
In this paper, we consider the following problem. Given four distinct vertices v1, v2, v3, v4. How many edges guarantee the existence of seven connected disjoint subgraphs Xi for i = 1, . . . , 7 such that Xj contains vj for j = 1, 2, 3, 4 and for j = 1, 2, 3, 4, Xj has a neighbour to each Xk with k = 5, 6, 7. This is the so called “rooted K3,4-minor problem”. There are only few known results o...
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Let d and S? be two intersecting families of k-subsets of an n-element set. It is proven that l~.JuS?l <(;:i)+(;::) holds for n>f(3+,/?)k, and equality holds only if there exist two points a, b such that {a, b} n F# 0 for all FE d u g, For n=2k+o(Jj;) an example showing that in this case max 1 d u B 1 = (1 o( 1 ))( ;) is given. This disproves an old conjecture of Erdiis [7]. In the second part ...
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ژورنال
عنوان ژورنال: International Mathematical Forum
سال: 2007
ISSN: 1314-7536
DOI: 10.12988/imf.2007.07286