A rare benefit of the Covid-situation is that Richard Borcherds decided to set up a YouTube channel with recordings of his online lectures.

Plenty of gems to be discovered there, including a talk on Monstrous Moonshine, and a talk he gave for the Archimedeans about the Sporadic Groups.

As part of his History of Science-course he addressed the question whether Witt discovered the Leech lattice.

A while ago I’ve blogged about that very same question here:

- Who discovered the Leech lattice?
- So, who discovered the Leech lattice?
- Erna Bannow, octonions and the Leech

The summary of these posts being that I thought it was rather unlikely for Witt to have discovered the Leech lattice.

However, using the same sources, Borcherds rates a more than 90% probability for Witt to have indeed discovered the Leech lattice in 1940.

His evidence for this is:

- Witt said he discovered it.
- His construction (in his 1972 colloquium talk) is unlike any other construction of the Leech lattice.
- Witt was
**the**expert on Steiner systems, and the system S(5,8,24) is crucial in Leech’s construction of his lattice.

### Similar Posts:

- Erna Bannow, octonions and the Leech?
- Who discovered the Leech lattice?
- So, who did discover the Leech lattice?
- Witt and his Niemeier lattices
- The Leech lattice neighbour
- symmetry and the monster
- Arnold’s trinities version 2.0
- Borcherds’ monster papers
- Know thy neighbours
- a monstrous unimodular lattice

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