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notes on tao paper

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Phil's brief commentary on a paper by Tao, written 6.29.15 in the Buck Advanced Calculus folder. He likes the writing style but loses the thread at forms as linear functionals, tangent and cotangent vectors, wedge products, and push-forward and pull-back. He notes the paper lacks pictures and examples and says he needs a more systematic treatment.

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Notes on the Tao paper PhL 6.29.15 I like the style of writing, and it is only 10 pages. It compares 1D to nD integration, and the latter is much more complicated. Unfortunately, I lose the thread when the author starts talking about the form as being a mapping from En → E1 which is a linear functional. He uses the example of work which yes, is a scalar. The examples I am most used to have a dot product like ω = F dx where ω is the 1-form and where F is an associated vector function. But this author wants to generalize to manifolds which don't have dot products. It seems that my understanding of a "tangent vector" is not what Tao is talking about, and then he also has "cotangent vectors" which is even more confusing. No pictures, no examples. He likes to define a curve on [0,1] and a surface on [0,1]2 for the variables like u and v. He works in the wedge product, but it just is not done clearly for me. This appears with 2-forms and yes, it is a 2-piped though which some flux flows. The Hodge duality exists only for E3. Since I am confused by the tangent and cotangent vectors, I am also confused by his discussion of such vectors being pushed forward and pulled back through a mapping, though I dimly see what this might mean. I need a more systematic discussion. ********************