User Walter Simon

1 vote

0 answers

53 views

If $B$ is a flat $A$-algebra then $B_{\mathrm{red}}$ is a flat $A_{\mathrm{red}}$-algebra

asked Apr 14, 2020 at 21:36

0 votes

1 answer

33 views

On an separated variety, $\mathcal{O}_{X,Y_1}\subseteq \mathcal{O}_{X,Y_2}$ then $Y_2\subseteq Y_1$

asked Apr 8, 2020 at 12:54

5 votes

0 answers

188 views

Tangent vector fields on schemes

asked Aug 21, 2019 at 17:57

2 votes

0 answers

287 views

Map between stalks induced by a finite morphism is finite

asked Mar 5, 2019 at 13:01

2 votes

1 answer

597 views

The residue field of valuations are finite extension

asked Feb 12, 2019 at 20:48

1 vote

2 answers

88 views

$p$-adic power series and its maximum in the unit ball

asked Feb 7, 2019 at 14:51

6 votes

0 answers

253 views

Flatness criterion for a finite type algebra based on the Jacobian

asked Feb 4, 2019 at 19:42

5 votes

3 answers

2k views

If $L\mid K$ is a finite extension of fields then K is perfect iff L is perfect

asked Feb 3, 2019 at 22:34

5 votes

1 answer

817 views

The surjective image of a proper scheme is proper

asked Dec 13, 2018 at 16:53

0 votes

1 answer

81 views

Homogeneous elements of the polynomial ideal $(x_1-a_1,\dots,x_n-a_n)$ belong to $(x_ia_j-x_ja_i)_{ij}$

asked Oct 28, 2018 at 21:25

0 votes

1 answer

29 views

If a set of linear functionals define semispaces that cover the space then they are linearly dependent.

asked Sep 2, 2018 at 0:17

1 vote

0 answers

295 views

Characterization of the convex hull in terms of dot product

asked Aug 7, 2018 at 17:59

2 votes

1 answer

241 views

The dual of a regular polyhedral cone is regular

asked Aug 3, 2018 at 20:15

3 votes

0 answers

298 views

Certain generators for the normalization of the cuspidal cubic $x^3=y^2$

asked May 23, 2018 at 14:18

1 vote

0 answers

291 views

Basic criterion for affineness of schemes

asked May 1, 2018 at 21:36

2 votes

1 answer

81 views

Generators for the $n$-derived group $G^{(n)}$ and the lower central series $G^{n}$

asked Feb 7, 2018 at 20:32

0 votes

2 answers

157 views

Finite structures of a theory have finite atomic diagram.

asked Feb 1, 2018 at 0:07

0 votes

0 answers

67 views

Flex points are invariant under isomorphism

asked Jan 21, 2018 at 22:08

1 vote

1 answer

459 views

Definition of scheme defined over a ring A

asked Jan 18, 2018 at 18:42

1 vote

0 answers

40 views

$\mathbb{Z}/2^n\mathbb{Z}$ as a certain quotient of $\oplus_{k=0}^n\mathbb{Z}$

asked Oct 22, 2017 at 16:16

7 votes

2 answers

3k views

Understanding the $\Delta$-complex structure of a quotient space

asked Oct 17, 2017 at 22:08

1 vote

1 answer

817 views

Exact additive functor preserves homology

asked Oct 10, 2017 at 23:59

2 votes

0 answers

235 views

Sheaf of $\mathcal{O}_X$-modules with support a point.

asked Sep 24, 2017 at 21:46

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23 Questions

If $B$ is a flat $A$-algebra then $B_{\mathrm{red}}$ is a flat $A_{\mathrm{red}}$-algebra

On an separated variety, $\mathcal{O}_{X,Y_1}\subseteq \mathcal{O}_{X,Y_2}$ then $Y_2\subseteq Y_1$

Tangent vector fields on schemes

Map between stalks induced by a finite morphism is finite

The residue field of valuations are finite extension

$p$-adic power series and its maximum in the unit ball

Flatness criterion for a finite type algebra based on the Jacobian

If $L\mid K$ is a finite extension of fields then K is perfect iff L is perfect

The surjective image of a proper scheme is proper

Homogeneous elements of the polynomial ideal $(x_1-a_1,\dots,x_n-a_n)$ belong to $(x_ia_j-x_ja_i)_{ij}$

If a set of linear functionals define semispaces that cover the space then they are linearly dependent.

Characterization of the convex hull in terms of dot product

The dual of a regular polyhedral cone is regular

Certain generators for the normalization of the cuspidal cubic $x^3=y^2$

Basic criterion for affineness of schemes

Generators for the $n$-derived group $G^{(n)}$ and the lower central series $G^{n}$

Finite structures of a theory have finite atomic diagram.

Flex points are invariant under isomorphism

Definition of scheme defined over a ring A

$\mathbb{Z}/2^n\mathbb{Z}$ as a certain quotient of $\oplus_{k=0}^n\mathbb{Z}$

Understanding the $\Delta$-complex structure of a quotient space

Exact additive functor preserves homology

Sheaf of $\mathcal{O}_X$-modules with support a point.