The joints problem in R^n
arXiv:0906.0555
Abstract
We show that given a collection of A lines in \R^n, n\geq 2, the maximum number of their joints (points incident to at least n lines whose directions form a linearly independent set) is O(A^{n/(n-1)}). An analogous result for smooth algebraic curves is also proven.
6 pages, removed erroneous argument that appeared in version 2 about incidences