On set systems with restricted intersections modulo p and p-ary t-designs

نویسنده

  • Richard M. Wilson
چکیده

We consider bounds on the size of families F of subsets of a v-set subject to restrictions modulo a prime p on the cardinalities of the pairwise intersections.We improve the known bound when F is allowed to contain sets of different sizes, but only in a special case. We show that if the bound for uniform families F holds with equality, then F is the set of blocks of what we call a p-ary t-design for certain values of t . This motivates us to make a few observations about p-ary t-designs for their own sake. © 2009 Published by Elsevier B.V.

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عنوان ژورنال:
  • Discrete Mathematics

دوره 309  شماره 

صفحات  -

تاریخ انتشار 2009