Discrete & Computational Geometry ( IF 0.6 ) Pub Date : 2021-05-04 , DOI: 10.1007/s00454-021-00302-7 Simeon Ball , Enrique Jimenez
Let \({\mathscr {S}}\) be a set of n points in real four-dimensional space, no four coplanar and spanning the whole space. We prove that if the number of solids incident with exactly four points of \({\mathscr {S}}\) is less than \(Kn^3\) for some \(K=o(n^{{1}/{7}})\) then, for n sufficiently large, all but at most O(K) points of \({\mathscr {S}}\) are contained in the intersection of five linearly independent quadrics. Conversely, we prove that there are finite subgroups of size n of an elliptic curve that span less than \(n^3/6\) solids containing exactly four points of \({\mathscr {S}}\).
中文翻译:
在定义几个普通实体的集合上
令\({\ mathscr {S}} \)为实四维空间中的n个点的集合,没有四个共面且跨越整个空间。我们证明,如果固体入射与恰好四个点的数量\({\ mathscr {S}} \)小于\(KN ^ 3 \)对于一些\(K = O(N ^ {{1} / {7}})\),然后,对于n足够大的情况,\({\ mathscr {S}} \)的所有O(K)点(至多O(K)点)都包含在五个线性独立二次曲面的交点中。相反,我们证明了椭圆曲线的大小为n的有限子组,其跨度小于\(n ^ 3/6 \)恰好包含\({\ mathscr {S}} \)四点的实体。