User Qfwfq

1 vote

When forgetting structure doesn't matter

answered Apr 30, 2022 at 13:13

9 votes

What are the most misleading alternate definitions in taught mathematics?

answered Dec 9, 2020 at 21:19

1 vote

Is a smooth transformation of a plane domain onto a plane domain with everywhere nonzero Jacobian determinant necessarily a bijection?

answered Sep 6, 2020 at 17:44

6 votes

How to define jet bundles algebraically?

answered Aug 17, 2020 at 11:38

2 votes

What are the occurrences of stacks outside algebraic geometry, differential geometry, and general topology?

answered May 31, 2020 at 18:51

8 votes

The origin(s) of the word "elliptic"

answered May 8, 2020 at 16:01

2 votes

Modeling in pure math

answered Dec 16, 2019 at 16:45

3 votes

Is every finite-order unimodular matrix conjugate to a $0,1,-1$ matrix?

answered Nov 25, 2019 at 21:18

3 votes

Lie groupoids in practice

answered Nov 15, 2019 at 14:20

3 votes

Accepted

$\mathbb{R}$-like spaces

answered Oct 8, 2019 at 6:51

1 vote

Is Cohen immersion conjecture (theorem) known for vector bundles?

answered May 21, 2019 at 13:33

1 vote

Accepted

Map between localizations induces map on underlying modules for Zariski covering

answered May 15, 2019 at 10:46

3 votes

Accepted

Automorphisms of Schemes and their $A$-points

answered Apr 29, 2019 at 15:09

2 votes

Supermanifolds — elementary introduction?

answered Dec 30, 2018 at 17:29

8 votes

Defining algebraic manifold without referring to schemes

answered Dec 7, 2018 at 23:33

3 votes

Almost complex structure corresponds to unique complex structure up to biholomorphism

answered Dec 7, 2018 at 18:36

0 votes

Two homeomorphic non-diffeomorphic complex manifolds

answered Dec 4, 2018 at 20:08

0 votes

Smooth functions on sphere

answered Nov 27, 2018 at 0:37

0 votes

Recommended books/lecture notes for vector bundle on algebraic curve

answered Nov 7, 2018 at 18:55

1 vote

Question on Hartogs's Extension Theorem

answered Aug 22, 2018 at 15:57

3 votes

Curl as a divergence... Is it possible?

answered Aug 3, 2018 at 21:13

5 votes

What is the interface between functional analysis and algebraic geometry?

answered Jul 18, 2018 at 20:53

1 vote

Characterizing specific "concrete" mathematical objects by abstract general properties

answered May 20, 2018 at 23:07

1 vote

Characterizing specific "concrete" mathematical objects by abstract general properties

answered May 20, 2018 at 16:10

7 votes

What are Lie groupoids intuitively?

answered Apr 23, 2018 at 6:33

61 votes

What recent discoveries have amateur mathematicians made?

answered Apr 20, 2018 at 11:31

5 votes

Why the circle for Pontryagin duality?

answered Feb 28, 2018 at 2:52

1 vote

What information is lost in $X \to \mathrm{Sh}(X)$?

answered Feb 21, 2018 at 22:11

10 votes

If $X$ and $Y$ are homotopy equivalent, then are $X \times \mathbb{R}^{\infty}$ and $Y \times \mathbb{R}^{\infty}$ homeomorphic?

answered Feb 20, 2018 at 0:40

13 votes

Classical point-set topology using Grothendieck topologies

answered Feb 18, 2018 at 19:04

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114 Answers

When forgetting structure doesn't matter

What are the most misleading alternate definitions in taught mathematics?

Is a smooth transformation of a plane domain onto a plane domain with everywhere nonzero Jacobian determinant necessarily a bijection?

How to define jet bundles algebraically?

What are the occurrences of stacks outside algebraic geometry, differential geometry, and general topology?

The origin(s) of the word "elliptic"

Modeling in pure math

Is every finite-order unimodular matrix conjugate to a $0,1,-1$ matrix?

Lie groupoids in practice

$\mathbb{R}$-like spaces

Is Cohen immersion conjecture (theorem) known for vector bundles?

Map between localizations induces map on underlying modules for Zariski covering

Automorphisms of Schemes and their $A$-points

Supermanifolds — elementary introduction?

Defining algebraic manifold without referring to schemes

Almost complex structure corresponds to unique complex structure up to biholomorphism

Two homeomorphic non-diffeomorphic complex manifolds

Smooth functions on sphere

Recommended books/lecture notes for vector bundle on algebraic curve

Question on Hartogs's Extension Theorem

Curl as a divergence... Is it possible?

What is the interface between functional analysis and algebraic geometry?

Characterizing specific "concrete" mathematical objects by abstract general properties

Characterizing specific "concrete" mathematical objects by abstract general properties

What are Lie groupoids intuitively?

What recent discoveries have amateur mathematicians made?

Why the circle for Pontryagin duality?

What information is lost in $X \to \mathrm{Sh}(X)$?

If $X$ and $Y$ are homotopy equivalent, then are $X \times \mathbb{R}^{\infty}$ and $Y \times \mathbb{R}^{\infty}$ homeomorphic?

Classical point-set topology using Grothendieck topologies