It's an introduction to Monstrous Moonshine, an unexpected connection between the monster group M and modular functions, with applications in theoretical physic

It's an introduction to Monstrous Moonshine, an unexpected connection between the monster group M and modular functions, with applications in theoretical physics, see Wikipedia [0] for a summary. [0] https://en.wikipedia.org/wiki/Monstrous_moonshine https://en.wikipedia.org/wiki/Monstrous_moonshine