Alternating subgroups of Coxeter groups and their spinor extensions

O. V. Ogievetsky, L. Poulain d'Andecy

Let $G$ be a discrete Coxeter group, $G^{+}$ its alternating subgroup and ${\tilde{G}}^{+}$ the spinor cover of $G^{+}$. A presentation of the groups $G^{+}$ and ${\tilde{G}}^{+}$ is proved for…