Generalizations of Joints Problem
arXiv:1606.08525
Abstract
We generalize the joints problem to sets of varieties and prove almost sharp bound on the number of joints. As a special case, given a set of -planes in , the number of points at which three -planes intersect and span is at most . We also get almost sharp bound on the number of joints with multiplicities. The main tools are polynomial partitioning and induction on dimension.