In this paper, we prove several extremal results for geometrically defined hypergraphs. In particular, we establish an improved lower bound, single exponentially decreasing in k, on the best constant delta > 0 such that the vertex classes P-1,...,P-k of every k -partite k -uniform semialgebraic hypergraph H = (P-1 U center dot center dot center dot U P-k, E) with vertical bar E vertical bar >= epsilon ll(j=1)(k) vertical bar P-i vertical bar have, for 1
Colin Neil Jones, Yuning Jiang, Yingzhao Lian, Xinliang Dai