Holomorphic vertex operator algebras of central charge 24

Borcherds showed that there is a 1-to-1 correspondence between the deep holes in the Leech lattice and the Niemeier lattices with non-trivial root system. This allows a geometric classification of these lattices. We show that a similar approach is possible for the holomorphic vertex operator algebras of central charge 24. This is work in progress with Sven Möller.