It is well known that exceptional group F_4 is a subgroup of SO(26). What SO(26)/F_4 is as an algebraic variety?

Since F_4 is reductive, the quotient SO(26)/F_4 is an affine algebraic variety. Is there any explicit description of this variety, that would also include the action of SO(26) on? Say, as a closed...

26 January 2018 6,454 0 View