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This is called a trivial bundle. Examples of non-trivial fiber bundles include the Möbius strip and Klein bottle, as well as nontrivial covering spaces. Fiber bundles, such as the tangent bundle of a manifold and other more general vector bundles, play an important role in differential geometry and differential topology, as do principal bundles.
Discovered by Heinz Hopf in 1931, it is an influential early example of a fiber bundle. Technically, Hopf found a many-to-one continuous function (or "map") from the 3 -sphere onto the 2 -sphere such that each distinct point of the 2 -sphere is mapped from a distinct great circle of the 3 -sphere ( Hopf 1931 ). [ 1 ]
The Möbius strip can be constructed by a non-trivial gluing of two trivial bundles on open subsets U and V of the circle S 1.When glued trivially (with g UV =1) one obtains the trivial bundle, but with the non-trivial gluing of g UV =1 on one overlap and g UV =-1 on the second overlap, one obtains the non-trivial bundle E, the Möbius strip.
At each point in the fiber , the vertical fiber is unique. It is the tangent space to the fiber. The horizontal fiber is non-unique. It merely has to be transverse to the vertical fiber. In mathematics, the vertical bundle and the horizontal bundle are vector bundles associated to a smooth fiber bundle.
A Lagrangian: given a fiber bundle ′, the Lagrangian is a function : ′. Suppose that the matter content is given by sections of E {\displaystyle E} with fibre V {\displaystyle V} from above. Then for example, more concretely we may consider E ′ {\displaystyle E'} to be a bundle where the fibre at p {\displaystyle p} is V ⊗ T p ∗ M ...
A mapping : between total spaces of two fibrations : and : with the same base space is a fibration homomorphism if the following diagram commutes: . The mapping is a fiber homotopy equivalence if in addition a fibration homomorphism : exists, such that the mappings and are homotopic, by fibration homomorphisms, to the identities and . [2]: 405-406
For a fiber bundle with structure group , the transition functions of the fiber (i.e., the cocycle) in an overlap of two coordinate systems and are given as a -valued function on . One may then construct a fiber bundle F ′ {\displaystyle F'} as a new fiber bundle having the same transition functions, but possibly a different fiber.
The fibres of the bundle TP/G under the projection ρ carry an additive structure. The bundle TP/G is called the bundle of principal connections (Kobayashi 1957). A section Γ of dπ:TP/G→TM such that Γ : TM → TP/G is a linear morphism of vector bundles over M, can be identified with a principal connection in P.