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Zhen Lin

https://www.dpmms.cam.ac.uk/~zll22/

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Top Questions
132 votes

What concept does an open set axiomatise?

general-topology math-history asked Apr 9, 2011 at 5:23
math.stackexchange.com

101 votes

Sheaf cohomology: what is it and where can I learn it?

reference-request algebraic-topology algebraic-geometry soft-question sheaf-theory asked Jul 31, 2011 at 13:25
math.stackexchange.com

70 votes

Simplicial homology of real projective space by Mayer-Vietoris

algebraic-topology homology asked Mar 14, 2011 at 18:16
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49 votes

Is $\operatorname{height} \mathfrak{p} + \dim A / \mathfrak{p} = \dim A$ true?

reference-request commutative-algebra krull-dimension dimension-theory-algebra asked Jul 3, 2011 at 4:13
math.stackexchange.com

48 votes

Proving the snake lemma without a diagram chase

commutative-algebra category-theory homological-algebra abelian-categories asked Oct 22, 2011 at 16:47
math.stackexchange.com

47 votes

When does pointwise convergence imply uniform convergence?

real-analysis sequences-and-series functional-analysis uniform-convergence asked May 20, 2011 at 10:59
math.stackexchange.com

44 votes

Strong and weak convergence in $\ell^1$ (Schur's theorem)

functional-analysis convergence banach-spaces lp-spaces weak-convergence asked Jun 1, 2011 at 17:54
math.stackexchange.com

44 votes

Closed model categories in the sense of Quillen [1969] vs the modern sense

category-theory homotopy-theory model-categories asked Feb 10, 2013 at 23:41
math.stackexchange.com

44 votes

TOC entries and labels for included PDF pages

sectioning hyperref table-of-contents pdfpages asked Apr 17, 2011 at 9:32
tex.stackexchange.com

43 votes

Why do universal $\delta$-functors annihilate injectives?

homological-algebra cohomology abelian-categories derived-functors asked Mar 30, 2012 at 0:37
math.stackexchange.com

1 2 3 4 5 … 10

Top Answers
74
Why did my friend lose all his money?
math.stackexchange.com

62
Why is the category of fields seemingly so poorly behaved?
math.stackexchange.com

59
What is the 'implicit function theorem'?
math.stackexchange.com

57
Understanding Ramification Points
math.stackexchange.com

56
What are differences between affine space and vector space?
math.stackexchange.com

54
Is Zorn's lemma required to prove the existence of a maximal atlas on a manifold?
math.stackexchange.com

54
In set theory, how are real numbers represented as sets?
math.stackexchange.com

53
Zero probability and impossibility
math.stackexchange.com

49
Do De Morgan's laws hold in propositional intuitionistic logic?
math.stackexchange.com

45
Surjectivity of $f:S\to S$ implies injectivity for finite $S$, and conversely
math.stackexchange.com

45
Quotient objects, their universal property and the isomorphism theorems
math.stackexchange.com

44
When to learn category theory?
math.stackexchange.com

41
What are the Axiom of Choice and Axiom of Determinacy?
math.stackexchange.com

40
Question about perfect pairings
math.stackexchange.com

38
Why must we distinguish between rational and irrational numbers?
math.stackexchange.com

38
Why use ZF over NFU?
math.stackexchange.com

35
Tautological 1-form on the cotangent bundle
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34
Are some real numbers "uncomputable"?
math.stackexchange.com

34
Does taking the direct limit of chain complexes commute with taking homology?
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31
Best way to learn Algebraic Geometry?
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31
Good references for stacks
math.stackexchange.com

30
Gluing sheaves - can we realize $\mathcal{F}(W)$ as some kind of limit?
math.stackexchange.com

30
How many Kanji characters are there?
japanese.stackexchange.com

28
Does "cheap nonstandard analysis" take place in a topos?
math.stackexchange.com

28
Vector bundle transitions and Čech cohomology
math.stackexchange.com

26
Can the Category of Schemes be Concretized?
mathoverflow.net

26
Why are de Rham cohomology and Cech cohomology of the constant sheaf the same
math.stackexchange.com

25
Sheaf-theoretic approach to forcing
mathoverflow.net

25
In what sense does a number "exist" if it is proven to be uncomputable?
math.stackexchange.com

23
What is a Lawvere-Tierney topology?
math.stackexchange.com

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