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Walter Simon's user avatar
Walter Simon's user avatar
Walter Simon's user avatar
Walter Simon
  • Member for 8 years, 1 month
  • Last seen more than a month ago
7 votes
2 answers
3k views

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

6 votes
0 answers
248 views

Flatness criterion for a finite type algebra based on the Jacobian

5 votes
1 answer
761 views

The surjective image of a proper scheme is proper

5 votes
3 answers
2k views

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

5 votes
0 answers
184 views

Tangent vector fields on schemes

3 votes
0 answers
280 views

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

2 votes
1 answer
233 views

The dual of a regular polyhedral cone is regular

2 votes
0 answers
228 views

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

2 votes
1 answer
80 views

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

2 votes
1 answer
547 views

The residue field of valuations are finite extension

2 votes
0 answers
274 views

Map between stalks induced by a finite morphism is finite

1 vote
0 answers
53 views

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

1 vote
0 answers
286 views

Basic criterion for affineness of schemes

1 vote
1 answer
770 views

Exact additive functor preserves homology

1 vote
0 answers
40 views

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

1 vote
1 answer
421 views

Definition of scheme defined over a ring A

1 vote
0 answers
277 views

Characterization of the convex hull in terms of dot product

1 vote
2 answers
84 views

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

0 votes
1 answer
27 views

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

0 votes
1 answer
79 views

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

0 votes
0 answers
66 views

Flex points are invariant under isomorphism

0 votes
2 answers
154 views

Finite structures of a theory have finite atomic diagram.

0 votes
1 answer
33 views

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