12/05/05 18:39:31.51
>>145
つづき
英語のページから下記へリンクが
”Principal homogeneous space”のことですな（数学科２年に成り立て程度じゃ面食らうかな）
URLﾘﾝｸ(en.wikipedia.org)
Principal homogeneous space
In mathematics, a principal homogeneous space, or torsor, for a group G is a homogeneous space X for G such that the stabilizer subgroup of any point is trivial.
Equivalently, a principal homogeneous space for a group G is a set X on which G acts freely and transitively,
so that for any x, y in X there exists a unique g in G such that x・g = y where ・ denotes the (right) action of G on X. An analogous definition holds in other categories where, for example,
・ G is a topological group, X is a topological space and the action is continuous,
・ G is a Lie group, X is a smooth manifold and the action is smooth,
・ G is an algebraic group, X is an algebraic variety and the action is regular.
（以下略）
URLﾘﾝｸ(en.wikipedia.org)
Maurer?Cartan form （英文）