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 1306

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

10 votes

Looking for ways how to calculate $\Phi_n(i)$

Let me try to summarize what I said in the comment to your question and what I implicitly used in what did not fit in the comment. As you will instantly see, the answer is lengthy because of high-scho …
Vladimir Dotsenko's user avatar
4 votes

Product of Fibonacci numbers

A follow-up to the comment of Anonymous which addresses your question exactly: see slides 9-13 here for an investigation of your question. Basically, it can be proved that the decomposition into a pro …
Vladimir Dotsenko's user avatar
16 votes
Accepted

Cyclotomic polynomials.

If this were true, then you would prove that $\Phi_m(x)$ and $\Phi_n(x)$ are coprime after reduction modulo $p$, which is far from true. For instance, $\Phi_4(x)=x^2+1$ and $\Phi_2(x)=x+1$ are not cop …
Vladimir Dotsenko's user avatar
12 votes
3 answers
860 views

Dirichlet series with integer coefficients as a UFD

I recall the following question from Ulam's book "Unsolved math problems": show that the ring of Dirichlet series with integer coefficients is a factorial ring. I believe that soon after Ulam wrote hi …
Vladimir Dotsenko's user avatar
2 votes
Accepted

Reference request for an identity for tangent numbers

The following is too long for a comment, so let me type it as an answer though it does not literally answer your question. Using the standard formula $$ T\_{2k-1}=(-1)^{k-1}2^{2k}(2^{2k}-1)\frac{B_{ …
Vladimir Dotsenko's user avatar
6 votes

Where is number theory used in the rest of mathematics?

1) For your third interpretation I have at least one relevant experience of my own - "factor systems" (some) number theorists deal with when talking about central simple algebras over number fields di …
6 votes

Where is number theory used in the rest of mathematics?

One thing I completely forgot of was reminded to me by the reference to Feit-Thompson conjecture: applications of number theory/basic Galois theory to characters of finite groups and to structure theo …
5 votes
Accepted

Show that sets are equal

Use the standard notations $e_k=\sum_{A\subset \{1,\dots,n\}, |A|=k} \prod_{i\in A} x_i$, with the conventions $e_0=1$ and $e_m=0$ for $m>n$; $p_k=\sum_{i=1}^n x_i^k$. If $n=p$, the statement is true …
Vladimir Dotsenko's user avatar
2 votes

Show that sets are equal

Let me prove that if for two sets of $n$ distinct numbers $X=\{x_1,\ldots,x_n\}$ and $Y=\{y_1,\ldots,y_n\}$ the sums of $k$th powers for $k=1,\ldots,2n-1$ are the same, then $X=Y$, irrespectively of t …
Vladimir Dotsenko's user avatar
1 vote

How do I find abelian cubic extension over $\mathbb{Q}$ with class number more than 1?

The earliest result I know which leads to many examples is that of Uchida: Uchida, K.: Class numbers of cubic cyclic fields. J. Math. Soc. Japan 26(3): 447-453 (July, 1974) See also Washington, L. …
Vladimir Dotsenko's user avatar
13 votes

linear independence of $\sin(k \pi / m)$

We have $$\sin\frac{\pi}{9}+\sin\frac{2\pi}9-\sin\frac{4\pi}9=\sin\frac{2\pi}{18}+\sin\frac{4\pi}{18}-\sin\frac{8\pi}{18}=\sin\frac{2\pi}{18}-\sin\frac{8\pi}{18}+\sin\frac{14\pi}{18},$$ and the latte …
Vladimir Dotsenko's user avatar
7 votes

How and when do I learn so much mathematics?

My personal experience suggests that reaching reasonable breadth of mathematical scope is achieved through three different mechanisms : 1) Attending talks (seminars, colloquia, workshops) in subjects …
43 votes
Accepted

Is there a natural bijection from $\mathbb{N}$ to $\mathbb{Q}$?

There is a following result which is quite lovely, I think (I don't remember right away whose result this is): Let us define a function $f\colon\mathbb{N}\to\mathbb{Q}^+$ as follows: $f(1)=1$, and al …
Vladimir Dotsenko's user avatar
7 votes

Asymptotics for the number of abelian groups of order at most $x.$

One reference where the asymptotic result you are asking for was first established (I think), as well as some reasonable growth estimates for $a_n$, is D.G.Kendall and R.A.Rankin, "On the number of A …
Vladimir Dotsenko's user avatar
13 votes
Accepted

Conjectured relation between alternating Prime zeta series and Riemann zeta

We have $$\sum_k\frac{(-1)^kP(nk)}{k}=\sum_{k,p}\frac{(-1)^k}{kp^{nk}}=-\sum_p\ln\left(1+\frac{1}{p^n}\right)=\sum_p\ln\left(\frac{1-\frac{1}{p^{n}}}{1-\frac{1}{p^{2n}}}\right)=\ln\frac{\zeta(2n)}{\ze …
Vladimir Dotsenko's user avatar

15 30 50 per page