Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with schemes
Search options not deleted
user 2191
The first purpose of schemes theory is the geometrical study of solutions of algebraic systems of equations, not only over the real/complex numbers, but also over integer numbers (and more generally over any commutative ring with 1). It was finalized by Alexandre Grothendieck, during the 1950s and the 1960s.
0
votes
Accepted
Are "strongly finite dimensional" homotopy invariant sheaves with transfers (locally) constant?
I have proved this statement as Lemma 5.1.3 at Bondarko and Sosnilo - On Chow-weight homology of geometric motives. Comments are very welcome!
- 16.9k
3
votes
1
answer
174
views
Are "strongly finite dimensional" homotopy invariant sheaves with transfers (locally) constant?
Moreover, I am actually interested in the extension of $S$ to pro-smooth (say, affine) $k$-schemes; and my finite dimensionality assumption corresponds to the finite dimensionality of $S(\operatorname{ …
- 16.9k
4
votes
1
answer
228
views
Which valuations of a field yield codimension $1$ subschemes of their 'models'
For a field $F$ (for example, a one generated by a finite number of its elements) there is a directed set of its 'models' (in this case those are 'arithmetic' schemes whose fraction field is $F$). …
- 16.9k
2
votes
0
answers
175
views
Regular subscheme of a projective limit of schemes
I am actually only interested in equicharacteristic schemes, and the connecting morphisms are affine and dominant. …
- 16.9k
4
votes
1
answer
525
views
Which schemes can be presented as limits of smooth varieties?
In this text I only treat schemes that are excellent separated of finite Krull dimension. So, I have the following questions. … Is there an interesting subclass in the class of all limit schemes of this sort? I don't want to restrict myself to affine schemes. …
- 16.9k
0
votes
0
answers
256
views
How would you call a subscheme of a smooth $S$-scheme?
In my preprint I propose to call $X/S$ quasi-smooth if $X$ can be embedded into a smooth $X'/S$. Does this sound fine?
Upd. So, smoothly embeddable is better? Is it ok to call a morphism smoothly emb …
- 16.9k
6
votes
0
answers
222
views
If $X,Y$ are regular and of finite type over $S$, can $X\times _S Y$ be embedded into a regu...
Now, I am interested in the following setting: $X,Y$ are regular schemes of finite type over $S$;
$S$ is separated excellent noetherian of finite Krull dimension (and one may assume that $X$ and $Y$ are …
- 16.9k
2
votes
1
answer
1k
views
Is every regular (excellent) scheme separated?
I need schemes that are regular, excellent and separated. Are these three conditions independent? …
- 16.9k
2
votes
0
answers
368
views
Can any radiciel morphism be presented as the composition of a universal homeomorphism with ...
As in my previous questions, I am interested in excellent schemes of finite Krull dimension. …
- 16.9k
6
votes
1
answer
814
views
More on universal homeomorphisms
Is a universal homeomorphism of connected regular (excellent finite dimensional) schemes an isomorphism if these schemes are not positive characterstic ones? … Suppose that a finite morphism $f:X\to Y$ of connected regular (excellent finite dimensional) schemes is generically purely inseparable. …
- 16.9k
4
votes
2
answers
331
views
Is the pre-image of a regular subscheme with respect to a universal homeomorphism of regular...
Let $f:X\to Y$ be a universal homeomorphism of regular (excellent finite-dimensional) schemes, $Z\subset Y$ be a regular subscheme. Is $f^{-1}(Z)$ necessarily regular? …
- 16.9k
2
votes
0
answers
215
views
When inverse image is conservative; a reference or a generalization?
I am interested in the following question: for $f$ being a morphism of schemes, which conditions ensure that $Rf^*_{et}$ is conservative? …
- 16.9k
5
votes
0
answers
734
views
Do all the main properties of constructible and perverse sheaves (in an 'arithmetic' situati...
This question is a continuation of Bad behaviour of perverse sheaves over 'general' bases?
Let $S$ (for example) be a finite type separated scheme over $\mathbb{Z}$. I would like: (1) to define the p …
- 16.9k
3
votes
0
answers
361
views
A presentation of a scheme as a limit of smooth ones over finitely generated bases
Which of the following statements are true:
If $S$ is regular, then it can be presented as a projective limit of smooth $\mathbb{Z}$-schemes. … If $S$ is regular, then it can be presented as a projective limit of schemes that are smooth over finite type regular $\mathbb{Z}$-ones. …
- 16.9k
6
votes
0
answers
305
views
Does one need l to be invertible in S in order to consider the l-adic cohomology of S-scheme...
What happens with $\mathbb{Q}_l$-adic cohomology of schemes if $l$ is not invertible in $S$ (but is not equal to the characteristic of $S$)? Will the Tate twist be invertible? …
- 16.9k