منابع مشابه
Hypergraphs with Zero Chromatic Threshold
Let F be an r-uniform hypergraph. The chromatic threshold of the family of F free, r-uniform hypergraphs is the infimum of all non-negative reals c such that the subfamily of F -free, r-uniform hypergraphs H with minimum degree at least c (|V (H)| r−1 ) has bounded chromatic number. The study of chromatic thresholds of various graphs has a long history, beginning with the early work of Erdős-Si...
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For ordinary graphs it is known that any graph G with more edges than the Turán number of Ks must contain several copies of Ks, and a copy of K− s+1, the complete graph on s+ 1 vertices with one missing edge. Erdős asked if the same result is true for K s , the complete 3-uniform hypergraph on s vertices. In this note we show that for small values of n, the number of vertices in G, the answer i...
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Let χ1(n) denote the maximum possible absolute value of an entry of the inverse of an n by n invertible matrix with 0, 1 entries. It is proved that χ1(n) = n 1 2. This solves a problem of Graham and Sloane. Let m(n) denote the maximum possible number m such that given a set of m coins out of a collection of coins of two unknown distinct weights, one can decide if all the coins have the same wei...
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ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1985
ISSN: 0012-365X
DOI: 10.1016/0012-365x(85)90080-9