出典:Wiktionary
orthogonal group (複数形 orthogonal groups)
Denoted O(n) in the real number case; O(n, F) in the general case.
In the case that F is the real numbers, the orthogonal group is equivalently definable as the group of distance-preserving transformations of an n-dimensional Euclidean space that preserve a given fixed point, where the group operation is that of composition of transformations.