Selecting Heavily Covered Points
Bernard Chazelle, Herbert Edelsbrunner, Leonidas Guibas, John E. Hershberger, Raimund Seidel, Micha Sharir · SIAM Journal on Computing · 1994
A collection of geometric selection lemmas is proved, such as the following: For any set P of n points in three-dimensional space and any set S of m spheres, where each sphere passes through a distinct point pair in P, there exists a point x, not necessarily in P, that is enclosed by $\Omega ({{m^2 } / {(n^2 \log ^6 \tfrac{{n^2 }}{m})}})$ of the spheres in S. Similar results apply in arbitrary fixed dimensions, and for geometric bodies other than spheres. The results have applications in reducing the size of geometric structures, such as three-dimensional Delaunay triangulations and Gabriel graphs, by adding extra points to their defining sets.