User Daniel Teixeira

6 votes

How to prove $f(x)=a$ is a subspace

answered Apr 15, 2018 at 6:52

5 votes

Pullback in the category of graphs

answered Jul 27, 2020 at 19:29

4 votes

Accepted

Flaw in a proof of uniqueness of products in a category?

answered Jul 14, 2020 at 14:57

4 votes

Accepted

Monoidal category: Inequivalent associators

answered Jul 27, 2020 at 12:11

4 votes

Meaning of curl defined as in differential geometry

answered Sep 27, 2022 at 16:26

3 votes

Using a smooth function to replace a coordinate on a manifold

answered Jan 4, 2021 at 13:43

3 votes

Monomorphisms of monoids

answered May 7, 2020 at 18:53

3 votes

What is the union of two varieties

answered Jul 30, 2020 at 0:50

3 votes

The set of all vector spaces

answered Jul 30, 2020 at 14:12

3 votes

Universal property for tensor product in an arbitrary category

answered Apr 28, 2020 at 0:41

3 votes

$x-y> 1$. How is this relation neither symmetric nor anti symmetric?

answered Apr 21, 2018 at 21:25

2 votes

Can the starting point of an infinite series be a non-integer?

answered Apr 21, 2018 at 21:44

2 votes

Is X a cover of itself?

answered Apr 24, 2018 at 18:00

2 votes

Rationalize this

answered Jun 27, 2018 at 13:47

2 votes

Why are the coefficients always equal?

answered Mar 26, 2019 at 1:05

2 votes

Tensor and Wedge

answered Apr 15, 2018 at 8:17

2 votes

Accepted

Let $U, V \in M_{n\times n}$ be orthogonal matrices. Explain why $UV$ is an orthogonal matrix

answered Apr 19, 2018 at 15:26

2 votes

Accepted

Define the fact that $Hom_{C}(X,Y)$ is bijective for category $C.$

answered Sep 30, 2020 at 20:32

2 votes

Concretely, what is the horn $\Lambda_k^n$?

answered Dec 9, 2020 at 22:29

2 votes

Accepted

Tuples of functions (with different domains and codomains)

answered Oct 31, 2022 at 15:41

1 vote

Accepted

Is Fock space a symmetric/exterior algebra?

answered May 23 at 17:14

1 vote

Accepted

Is there an $\infty$-category of spaces?

answered Jan 25, 2021 at 22:56

1 vote

Accepted

Skeletal categories and isomorphisms between an object and itself

answered Jun 9, 2021 at 21:07

1 vote

Accepted

Is the smash-hom adjunction a homeomorphism?

answered Sep 16, 2022 at 18:35

1 vote

Accepted

Are noncommutative diagrams well defined?

answered Sep 21, 2022 at 20:15

1 vote

Universal Cover of $SO^+(2,4)$

answered Jun 26, 2019 at 6:38

1 vote

Accepted

The Eckmann-Hilton argument gives us an isomorphism between $Mon(Mon(C))$ and $CoMon(C)$ or just an equivalence?

answered Apr 24, 2020 at 13:08

1 vote

Accepted

How to find the generators of a principal Ideal?

answered Aug 1, 2020 at 15:51

1 vote

The set of self-adjoint maps $P$ with $P^2=P$ and rank $k$ is a submanifold

answered Aug 26, 2020 at 22:46

1 vote

Accepted

A question on forms

answered May 7, 2020 at 19:47

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54 Answers

How to prove $f(x)=a$ is a subspace

Pullback in the category of graphs

Flaw in a proof of uniqueness of products in a category?

Monoidal category: Inequivalent associators

Meaning of curl defined as in differential geometry

Using a smooth function to replace a coordinate on a manifold

Monomorphisms of monoids

What is the union of two varieties

The set of all vector spaces

Universal property for tensor product in an arbitrary category

$x-y> 1$. How is this relation neither symmetric nor anti symmetric?

Can the starting point of an infinite series be a non-integer?

Is X a cover of itself?

Rationalize this

Why are the coefficients always equal?

Tensor and Wedge

Let $U, V \in M_{n\times n}$ be orthogonal matrices. Explain why $UV$ is an orthogonal matrix

Define the fact that $Hom_{C}(X,Y)$ is bijective for category $C.$

Concretely, what is the horn $\Lambda_k^n$?

Tuples of functions (with different domains and codomains)

Is Fock space a symmetric/exterior algebra?

Is there an $\infty$-category of spaces?

Skeletal categories and isomorphisms between an object and itself

Is the smash-hom adjunction a homeomorphism?

Are noncommutative diagrams well defined?

Universal Cover of $SO^+(2,4)$

The Eckmann-Hilton argument gives us an isomorphism between $Mon(Mon(C))$ and $CoMon(C)$ or just an equivalence?

How to find the generators of a principal Ideal?

The set of self-adjoint maps $P$ with $P^2=P$ and rank $k$ is a submanifold

A question on forms