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where a stable framing is a stable tangential structure $\mathcal{X} = EO \to BO$ (ref. Dan Freed's notes Exercise 9.50). This is Exercise 10.32 in Dan Freed's notes and I have no idea to get started with the proof. Could somebody sketch the main ideas and steps?

PhysicsMath
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1 Answers1

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The "Thom prespectrum" consists of spaces like $EO(n)^{S(n)}$ in each level. Each base space $EO(n)$ is contractible, so any vector bundle over it is trivial. The Thom complex of a trivial bundle is an iterated suspension of the base space. This gives you spheres (up to homotopy) in each level. Then it's just a matter of checking that the bonding maps are what you'd expect them to be.

JHF
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  • "The Thom complex of a trivial bundle is an iterated suspension of the base space." That is the key! Many thanks for the idea, JHF! – PhysicsMath Aug 02 '16 at 18:35