Framings and Projective Framings for 3-manifolds
نویسنده
چکیده
We give an elementary proof of the fact that any orientable 3-manifold admits a framing (i.e. is parallelizable) and any non-orientable 3-manifold admits a projective framing. The proof uses only basic facts about immersions of surfaces in 3-space.
منابع مشابه
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A framing of an oriented trivial bundle is a homotopy class of sections of the associated oriented frame bundle. This paper is a study of the framings of the tangent bundle τM of a smooth closed oriented 3-manifold M , often referred to simply as framings of M .1 We shall also discuss stable framings and 2-framings of M , that is framings of ε1 ⊕ τM (where ε1 is an oriented line bundle) and 2τM...
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تاریخ انتشار 2008