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arXiv · 1203.4188

Maximum hitting for n sufficiently large

Ben Barber
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Abstract

For a left-compressed intersecting family \A contained in [n]^(r) and a set X contained in [n], let \A(X) = {A in \A : A intersect X is non-empty}. Borg asked: for which X is |\A(X)| maximised by taking \A to be all r-sets containing the element 1? We determine exactly which X have this property, for n sufficiently large depending on r.

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Ben Barber. 2012-11-29. Maximum hitting for n sufficiently large. https://doi.org/10.1007/s00373-012-1281-9

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