Thierry Tuszynski

The 231 gates of the Sefer Yetzirah as the positive root system of A_21: Coxeter geometry of the letter-wheel, with cyclotomic and quasicrystalline perspectives

The Sefer Yetzirah (Book of Formation), a short Hebrew text of late antiquity, mounts an alphabet of 22 letters on a rotating wheel (galgal) and enumerates the 231 unordered pairs it calls gates. We identify these gates with the positive roots of the root system A_21: the letter-...