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John Klein's user avatar
John Klein's user avatar
John Klein's user avatar
John Klein
  • Member for 13 years, 8 months
  • Last seen this week
  • Metro Detroit. Brooklyn expatriate.
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I'm an algebraic topologist. I also like espresso.

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Top posts
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question
62
Thomason's "open letter" to the mathematical community
Oct 1, 2021
answer
35
Can anyone explain to me what is an assembly map?
Mar 2, 2012
question
28
On the (derived) dual to the James construction.
Feb 4, 2011
answer
26
Groupoid actions on spaces
Apr 29, 2011
answer
22
A map inducing isomorphisms on homology but not on homotopy
Aug 12, 2012
answer
19
Fibrations and Cofibrations of spectra are "the same"
Jul 29, 2014
answer
19
Is any CW complex with only finitely many nonzero homology groups homotopic to a finite dimensional CW complex?
Apr 26, 2017
answer
18
What is the intuition behind the Freudenthal suspension theorem?
Feb 23, 2011
question
18
Geometric interpretation of the Pontryagin square
Mar 25, 2011
answer
18
Realizing cohomology classes by submanifolds
May 24, 2019