Abstract
So-called exceptional isomorphisms of low-dimensional spinor groups are directly worked out for the terminal two cases of rank five and six (in the sense of quadratic modules) at the level of special Clifford groups with norm characters as group schemes over a ring. Explicit formulas of identifications are available on big cells, restrictions to which being justified by scheme theory.
Citation
Hisatoshi Ikai. "An approach through big cells to Clifford groups of low rank." Ark. Mat. 47 (2) 313 - 330, October 2009. https://doi.org/10.1007/s11512-008-0076-y
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