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Dec 8, 2020 at 8:37 answer added Denis Nardin timeline score: 8
Dec 7, 2020 at 20:07 history became hot network question
Dec 7, 2020 at 16:17 history edited Daniele Tampieri CC BY-SA 4.0
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Dec 7, 2020 at 13:16 review Close votes
Dec 14, 2020 at 3:09
Dec 7, 2020 at 12:28 answer added David E Speyer timeline score: 36
Dec 7, 2020 at 12:27 comment added Igor Belegradek A (complex) line bundle over $X$ is determined by its first Chern class in $H^2(X)$. In particular, if $H^2(X)=0$, then every line bundle over $X$ is trivial. On the other hand, such $X$ can admit a nontrivial complex vector bundle, e.g. if $\pi_i(U(n))$ is nontrivial, there is a nontrivial $\mathbb C^n$-bunlde over $S^{i+1}$.
Dec 7, 2020 at 12:10 comment added David E Speyer As a help for other people working on this question: The context is $C^{\infty}$ vector bundles on smooth manifolds.
Dec 7, 2020 at 12:07 review First posts
Dec 7, 2020 at 12:15
Dec 7, 2020 at 12:05 history asked Sunhf CC BY-SA 4.0