在数学中，带有结构群 G（拓扑群）的纤维丛理论允许产生一个配丛（associated bundle）的操作，将丛的典型纤维由 F₁ 变成 F₂，两者都是具有群 G 作用的拓扑空间。对具有结构群 G 的纤维丛 F，纤维在两个局部坐标系 U_α 与 U_β 交集上的转移函数（即上链）由一个 U_α∩U_β 上 G-值函数 g_αβ 给出。我们可以构造一个纤维丛 F′ 有同样的转移函数，但可能具有不同的纤维。

In mathematics, the theory of fiber bundles with a structure group (a topological group) allows an operation of creating an associated bundle, in which the typical fiber of a bundle changes from to , which are both topological spaces with a group action of . For a fibre bundle F with structure group G, the transition functions of the fibre (i.e., the cocycle) in an overlap of two coordinate systems U_α and U_β are given as a G-valued function g_αβ on U_α∩U_β. One may then construct a fibre bundle F′ as a new fibre bundle having the same transition functions, but possibly a different fibre.