Skip to main content
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
Search options not deleted user 120914

Prime numbers, diophantine equations, diophantine approximations, analytic or algebraic number theory, arithmetic geometry, Galois theory, transcendental number theory, continued fractions

4 votes

Compute generators of $\Gamma_0(N)$

sage should have what you need. Check under the documentation for the modular group. Specifically under generators you can find a couple of working examples for finding the generating set for $\Gamm …
Carl-Fredrik Nyberg Brodda's user avatar
4 votes
Accepted

What are the exceptional properties of Mersenne exponent for known largest prime?

Primes $p$ such that $2^p-1$ is prime are called Mersenne exponents. You can find many of their properties on the corresponding entry of the OEIS, namely A000043. Beyond their obvious connections with …
Carl-Fredrik Nyberg Brodda's user avatar
3 votes
Accepted

Behavior of biggest prime divisor of $n$ as $n$ grows large

The number of prime divisors of $n$ grows typically as $\log \log n$. Suppose $n$ has $k$ prime factors. Now $n/L(n)$ has only $k-1$ prime factors, so $$ k-1 \approx \log \log \frac{n}{L(n)} = \log \l …
Carl-Fredrik Nyberg Brodda's user avatar
8 votes
1 answer
650 views

Arithmetic sequences and Artin's conjecture

(Sorry if this is a naive question; it is not my area!) Consider the following strengthening of Artin's conjecture on primitive roots (and Dirichlet's theorem) for the case of $n=2$: every arithmetic …
Carl-Fredrik Nyberg Brodda's user avatar
15 votes
Accepted

Explanation for $\chi(\operatorname{SL}_2(\mathbb{Z})) = -1/12$ with zeta function

(Expanding my comment into an answer) It is not a coincidence. Relating the Euler characteristic of certain arithmetic groups to the Zeta function is a theorem due to Harder [1] from 1971. It is expan …
Carl-Fredrik Nyberg Brodda's user avatar
2 votes
Accepted

How to calculate genus number of number field using sage?

I may as well promote my comment to an answer, so this is closed. In a short paper, H. Hasse [1] computed the genus field and genus number of every real quadratic field. In particular, he shows that, …
Carl-Fredrik Nyberg Brodda's user avatar
25 votes

Why is integer factoring hard while determining whether an integer is prime easy?

Let me give a slightly different example. The Baumslag-Gersten group is a one-relator group with the presentation $\langle a, b \mid [a, a^b] = a\rangle$. This has a Dehn function which grows faster t …
Carl-Fredrik Nyberg Brodda's user avatar
5 votes
Accepted

Cohomology of $S$-arithmetic groups with trivial coefficients such as $H^n(\rm{PGL}_2(\mathb...

This is a hard problem in general. When $N$ is not prime, then even the first homology of $\operatorname{PSL}_2(\mathbf{Z}[\frac{1}{N}])$ is non-trivial to compute (cf. Corollary 4.4 of [1]), but I re …
Carl-Fredrik Nyberg Brodda's user avatar