Leech Lattice

The Leech lattice is an even unimodular lattice in twenty-four-dimensional Euclidean space, introduced by John Leech in 1965 while studying sphere packings, and it remains the densest known sphere packing in twenty-four dimensions, with each sphere touching 196,560 neighbors, the maximum possible in that dimension. The lattice's automorphism group is the Conway group, and the Leech lattice's exceptional symmetry connects it, through the Griess algebra construction, to the Monster group and to monstrous moonshine. Ernst Witt may have found the same lattice unpublished as early as 1940, but Leech's 1965 publication is the one credited with introducing it to the wider mathematical community. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/