词条 | Glossary of differential geometry and topology |
释义 |
This is a glossary of terms specific to differential geometry and differential topology. The following three glossaries are closely related:
See also:
Words in italics denote a self-reference to this glossary. {{compact ToC|side=yes|top=yes|num=yes}}AAtlasBBundle, see fiber bundle. CChartCobordismCodimension. The codimension of a submanifold is the dimension of the ambient space minus the dimension of the submanifold. Connected sumConnectionCotangent bundle, the vector bundle of cotangent spaces on a manifold. Cotangent spaceDDiffeomorphism. Given two differentiable manifoldsM and N, a bijective map from M to N is called a diffeomorphism if both and its inverse are smooth functions. Doubling, given a manifold M with boundary, doubling is taking two copies of M and identifying their boundaries. As the result we get a manifold without boundary. EEmbeddingFFiber. In a fiber bundle, π: E → B the preimage π−1(x) of a point x in the base B is called the fiber over x, often denoted Ex. Fiber bundleFrame. A frame at a point of a differentiable manifold M is a basis of the tangent space at the point. Frame bundle, the principal bundle of frames on a smooth manifold. FlowGGenusHHypersurface. A hypersurface is a submanifold of codimension one. IImmersionLLens space. A lens space is a quotient of the 3-sphere (or (2n + 1)-sphere) by a free isometric action of Zk. MManifold. A topological manifold is a locally Euclidean Hausdorff space. (In Wikipedia, a manifold need not be paracompact or second-countable.) A Ck manifold is a differentiable manifold whose chart overlap functions are k times continuously differentiable. A C∞ or smooth manifold is a differentiable manifold whose chart overlap functions are infinitely continuously differentiable. NNeat submanifold. A submanifold whose boundary equals its intersection with the boundary of the manifold into which it is embedded. PParallelizable. A smooth manifold is parallelizable if it admits a smooth global frame. This is equivalent to the tangent bundle being trivial. Principal bundle. A principal bundle is a fiber bundle P → B together with an action on P by a Lie group G that preserves the fibers of P and acts simply transitively on those fibers. PullbackSSectionSubmanifold, the image of a smooth embedding of a manifold. SubmersionSurface, a two-dimensional manifold or submanifold. Systole, least length of a noncontractible loop. TTangent bundle, the vector bundle of tangent spaces on a differentiable manifold. Tangent field, a section of the tangent bundle. Also called a vector field. Tangent spaceTorusTransversality. Two submanifolds M and N intersect transversally if at each point of intersection p their tangent spaces and generate the whole tangent space at p of the total manifold. TrivializationVVector bundle, a fiber bundle whose fibers are vector spaces and whose transition functions are linear maps. Vector field, a section of a vector bundle. More specifically, a vector field can mean a section of the tangent bundle. WWhitney sum. A Whitney sum is an analog of the direct product for vector bundles. Given two vector bundles α and β over the same base B their cartesian product is a vector bundle over B ×B. The diagonal map induces a vector bundle over B called the Whitney sum of these vector bundles and denoted by α⊕β. {{DEFAULTSORT:Glossary Of Differential Geometry And Topology}} 3 : Glossaries of mathematics|Differential geometry|Differential topology |
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