One of the exceptional Lie groups.
A description of as the special linear group in dimension 3 with values in the octonions is given in
Tevian Dray, Corinne A. Manogue, Octonions and the Structure of Comment. Math. Univ. Carolin., 51:193–207, 2010.
Aaron Wangberg, Tevian Dray, , the Group: The structure of (arXiv:1212.3182)
Cohomological properties are discussed in
Mamoru Mimura, Yuriko Sambe, Michishige Tezuka, Cohomology mod 3 of the classifying space of the exceptional Lie group , I : structure of Cotor (arXiv:1112.5811),
Cohomology mod 3 of the classifying space of the exceptional Lie group , II : The Weyl group invariants (arXiv:1201.3414)
See also