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Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeMar 10th 2019

added mentioning of the first two exceptional isos $Sp(1) \simeq Spin(3)$ and $Sp(2) \simeq Spin(5)$

• CommentRowNumber2.
• CommentAuthorUrs
• CommentTimeMar 19th 2019

A Riemannian manifold of dimension $4n$ is called a quaternion-Kähler manifold if its holonomy group is a subgroup of the direct product group $Sp(n) \times Sp(1)$.

• CommentRowNumber3.
• CommentAuthorJohn Baez
• CommentTimeJan 18th 2023

This group is also called the compact symplectic group, since both it and the symplectic group are real forms of the a complex Lie group. See more at compact symplectic group.

• CommentRowNumber4.
• CommentAuthorJohn Baez
• CommentTimeJan 18th 2023

I improved the page a bit more.