On a problem of Kleitman and West
Discrete Mathematics - Special issue: advances in graph labelling
An upper bound on the sum of squares of degrees in a graph
Discrete Mathematics
An upper bound on the sum of squares of degrees in a hypergraph
Discrete Mathematics
| Hi-index | 0.00 |
Among all collections of a given number of k-element subsets of an n-element groundset find a collection which maximizes the number of pairs of subsets which intersect in k–1 elements. This problem was solved for k=2 by Ahlswede and Katona, and is open for k2. We survey some linear algebra approaches which yield to estimations for the maximum number of pairs, and we present another short proof of the Ahlswede-Katona result.