bio  website  math.uchicago.edu/~may 

location  US  
age  74  
visits  member for  3 years, 9 months 
seen  4 hours ago  
stats  profile views  5,759 
At the University of Chicago since 1967.
Mainly known as an algebraic topologist.
6h

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The topology of the classifying space of U(n)
Standard: rational homotopy equivalence, meaning the two spaces become homotopy equivalent after rationalizing (when the Z's become Q's on the right). A suitable map from left to right is given by the Chern classes. 
1d

answered  Is there an analog of the BarrattEccles construction for E_∞groups and E_∞rings? 
Aug 24 
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PBW proof proposal
This is a sketch of a standard proof, and one does not have to restrict to characteristic zero. See Section 22.2 of ``More Concise Algebraic Topology" by Kate Ponto and myself for a recent version, which deals with graded Lie algebras. 
Aug 7 
awarded  modelcategories 
Aug 7 
answered  Is the category of $G$spaces a model category? 
Jul 31 
awarded  Nice Answer 
Jul 31 
answered  How much of homotopy theory can be done using only finite topological spaces? 
Jul 29 
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Fibrations and Cofibrations of spectra are “the same”
Just a small quibble. Fibration sequences and cofibration sequences give two structures of triangulated category to the homotopy category of spectra. One is the negative of the other: (f,g,h) is an exact triangle in one if and only if (f,g,h) is an exact triangle in the other. So they are not quite ``the same''. 
Jul 28 
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Adams' theorems on the HopfWhitehead Jhomomorphism
Right, Dustin: the space F = GL_1(S) is both additive (F) and multiplicative (GL_1(S)), and it is split by an exponential equivalence from J with its additive structure to J with its multiplicative structure. 
Jul 28 
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RO(G) grading of Mackey functors
I think you are still missing the point: many inequivalent representations have homotopy equivalent S^V: that is, as I said in the first place, the map from RO(G) to Pic is neither injective or surjective. This is not something you expect to calculate naively. 
Jul 28 
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RO(G) grading of Mackey functors
What it is is implicit in my answer: smashing with S^V gives you an action of the abelian group RO(G) on HoGS that factors through Pic(HoGS). You do not see the multiplication of RO(G) that way, so it is in no sensible sense an action of RO(G). 
Jul 28 
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RO(G) grading of Mackey functors
Not an operation of RO(G). You've got to learn the math. 
Jul 27 
answered  Algebraic $K$theory of algebras in symmetric spectra: reference 
Jul 27 
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RO(G) grading of Mackey functors
Delete the first use of ``how''. No meaning, no formula. 
Jul 26 
answered  RO(G) grading of Mackey functors 
Jul 12 
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Why localize spaces with respect to homology?
``What we really care about?" Mike, that depends on whether or not one is interested in applications and calculations. 
Jul 10 
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Why localize spaces with respect to homology?
Also, I would like to emphasize Craig's point. It is not that things are simpler but that there are new phenomena invisible before localization. Adams already was well aware of this. He implicitly proved that localizations of spheres at odd primes are Hspaces in a 1960 paper, and by the time of the notes he of course understood the role of localization in that statement. 
Jul 10 
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Why localize spaces with respect to homology?
Not from the text of the notes, but Frank was then visiting me at Chicago, and I can attest that not so far back in his mind was thinking about periodic localizations and periodicity phenomena in the stable homotopy groups of spheres, which he had been thinking about since 1960 or so. 
Jul 8 
awarded  Nice Answer 
Jul 8 
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Why localize spaces with respect to homology?
Thanks Vidit. Teach me privately how to do that, please. 