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 |
This tag is used if a reference is needed in a paper or textbook on a specific result.
4
votes
0
answers
123
views
Unramified Galois cohomology
Let $k$ be a local field with absolute Galois group $\Gamma_k$, inertia subgroup $I_k \subset \Gamma_k$, and residue field $\mathbb{F}$. Let $M$ be a finite Galois module over $k$.
The unramified Galo …
11
votes
0
answers
364
views
Example of abelian variety over finite field which doesn't lift
What is an example of an abelian variety over a finite field $\mathbb{F}_p$ which doesn't lift to $\mathbb{Z}_p$? This question seems to hint that they should exist, but no example is given.
Note that …
2
votes
Naive question on the Jacobian of a curve
If the Neron-Severi group of an abelian variety is $\mathbb{Z}$, then a principal polarisation, if it exists, is unique. This is the generic case, as well as for generic jacobians.
To find counter-exa …
4
votes
Accepted
Hardy-Littlewood circle method for non-diagonal quadratic forms
The "best" way to deal with quadratic forms using the circle method is via Heath-Brown's delta symbol method.
You can read about this in detail in the paper:
Heath-Brown - A New Form of the Circle Met …
4
votes
Character sums concerning $a^x-1$
Shparlinski has done a lot of work on problems like this, in the more general setting of linear recurrence sequences. (Your sequence of Mersenne numbers is such a sequence).
I'd recommend looking at C …
14
votes
Building algebraic geometry without prime ideals
This nice approach to points on schemes in fact becomes crucial once one leaves the world of schemes and travels to the galaxy of stacks.
For an algebraic stack $X$, one defines a point of $X$ to be a …
11
votes
Accepted
Reference request: Long exact sequence in profinite Galois cohomology up through $H^2$
See Section 5.7 of Serre's Galois Cohomology. (In general Chapter 5 of this book is a fairly definitive reference for non-abelian cohomology, and he works with an arbitrary profinite group $G$).
12
votes
1
answer
521
views
Equidistribution of $\{\alpha p\}$ for $p$ in an arithmetic progression
Let $\alpha$ be irrational. A famous theorem of Vinogradov says that $\{ \alpha p\}$ is equidistributed in $[0,1]$ as $p$ runs over all primes.
Let $a,q$ be natural numbers with $\gcd(a,q) = 1$. Then …
6
votes
Reference request: Diophantine equations
It is difficult to get far in the modern theory without some algebraic geometry.
This is the approach taken in the book:
Bjorn Poonen, Rational points on varieties, Graduate Studies in Mathematics 18 …
1
vote
Accepted
Existence of analytic continuation of Dirichlet series corresponding to the indicator sequen...
Serre deals with problems of this type in the paper:
Serre -Divisibilité de certaines fonctions arithmétiques
The fact you want should follow from the results in Sections 1 and 2.
Alternatively, th …
1
vote
Accepted
Logarithms of $L$-functions of irreducible characters of Galois group
Yes this is the fact that for a non-trivial irreducible Artin character, the associated Artin L-function is holomorphic and non-zero on $\rm{re}\, s \geq 1$.
For the trivial character, one just obtai …
3
votes
Computing the class group of a quadratic function field
The answer to the precise question is yes. See Theorem 1.2 of:
"Homological stability for Hurwitz spaces and the Cohen-Lenstra conjecture over function fields," https://arxiv.org/pdf/0912.0325.pdf.
…
6
votes
Accepted
Maps from products of Brauer-Severi varieties and sections
This is false. Take $X$ to be a smooth plane conic without a rational point. Consider the surface
$$S = X \times X.$$
Over the algebraic closure this becomes isomorphic to $\mathbb{P}^1 \times \mathbb …
14
votes
Accepted
Smooth proper variety over $\mathbb Q$ with everywhere bad reduction
As explained in the comments, there is no such variety.
This is an application of a general set of techniques called "spreading out". You can find a very nice treatment of this in Chapter 3 of the bo …
19
votes
5
answers
2k
views
Sum of the reciprocals of radicals
Recall that the radical of an integer $n$ is defined to be $\operatorname{rad}(n) = \prod_{p \mid n } p$.
For a paper, I need the result that
$$\sum_{n \leq x} \frac{1}{\operatorname{rad}(n)} \ll_\v …