101

Answers
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50
Do good math jokes exist? (2)
35
Is every functor a composition of adjoint functors?
35
Can anyone give me a good example of two interestingly different ordinary cohomology theories?
33
Cohomology and fundamental classes
23
What are some reasonable-sounding statements that are independent of ZFC?
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Why does non-abelian group cohomology exist?
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What is a continuous path?
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Does pointwise convergence imply uniform convergence on a large subset?
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Maximal ideals in the ring of continuous real-valued functions on R
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Are subfunctors of left exact functors also left exact?
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This is not a category. What is it?
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Elements of infinite order in a profinite group
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Whitehead for maps
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Are $G$-spectra the same as modules over a “group ring spectrum”?
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Is there a conceptual reason why topological spaces have quotient structures while metric spaces don’t?
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Are Thom spectra MU, MSO and K-theory spectra KU, KO modules over some truncations of the sphere spectrum?
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Rational Morava E-theory of cyclic groups
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Is every finite subcomplex of a contractible simplicial complex contained in a finite contractible subcomplex?
12
Pullbacks as manifolds versus ones as topological spaces
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Which sequences can be extended to analytic functions? (e. g., Ackermann’s function)
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Why the rank of a locally free sheaves is well defined?
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What do models where the CH is false look like?
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Why does the naive choice of homogeneous coordinate ring of a product of projective schemes not work?
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Left/right exact functor “in nature” which is not a right/left adjoint
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Is every functor inducing a homotopy equivalence a composition of adjoint functors?
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(Homotopy theory) When does the 2 of 3 property not imply 2 of 6?
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What is (co)homology, and how does a beginner gain intuition about it?
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Construction of maps S^3 -> S^2 with arbitrary Hopf invariant?
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The natural inclusion of an infinite abelian group $G$ into $\widehat{\widehat{G}}$
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“Skew Cohomology” of a Space
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