Spherical code

Summary

A spherical code is a finite set of points on the unit sphere in $\R^n$, judged by how far apart its points are. The main question asks for the largest number of points with a given minimal angle. The dual question asks for the largest minimal angle for a given number of points. Kissing configurations are spherical codes with minimal angle $60^\circ$, and the Tammes problem is the case $n = 3$. Upper bounds come mainly from the Delsarte linear programming bound.