Tagged Questions

4
votes
1answer
100 views

Sequences equdistributed modulo 1

Let $\alpha$ be any positive irrational and $\beta$ be any positive real. We have the following results. H. Weyl (1909): The fractional part of the sequence $\alpha n$ is equidist …
0
votes
0answers
6 views

Embedded associated prime

$\underline{\textbf{Embedded associated prime}}$ I am reading the book "Joins and Intersections". In the proof of Rees theorem I have some doubt. Let $\mathbf M$ be a finitely ge …
2
votes
2answers
829 views

Numbers of a different order?

Let $d_r$ be a divergent series of positive terms and let $s_r = \sum_{i=1}^{r}d_r$. We are interested in the sequence of numbers $S_{d_r} = s_1, s_2, \ldots$. For example if $d_r …
0
votes
0answers
11 views

Drect limit of sequences

Let $\mathcal{C}$ is a grothendiect category and consider all of what follows in $\mathcal{C}$. Let $${\varepsilon_i: 0\to A_i \to B_i \to C_i\to 0\ ,\ \phi_i^j}$$ be a direct sy …
1
vote
2answers
109 views

What are these compact sets called?

I'm wondering if a compact set $A\subset\mathbb{C}$ satisfying the properties that • $A$ and its complement have finitely many connected components • every connected component of …
0
votes
0answers
6 views

Group Action prolongation into associated fiber bundles

Suppose we have two topological groups $G$, $H$ and a $G$-principal bundle $(p:P \to M;G)$ over a manifold $M$ and $H$ is acting on $P$ (from the left or right. Whatever fits bett …
0
votes
0answers
13 views

Reference request: Minimal Axiomatizations of PA over (+,x,<=).

Many years ago, when I was still a high school student, I came up with a certain first-order axiomatization of PA over the signature (+, x, ≤). Out of nostalgia, I've decided t …
1
vote
2answers
53 views

Terminology: complex of sheaves with cohomology sheaves concentrated in degree zero

What is the proper terminology for a complex of sheaves $\mathcal F^\bullet$ whose homology sheaves $\mathcal H^i\mathcal F^\bullet$ vanish for $i\ne 0$?
0
votes
0answers
53 views

What is “Schreier Graph”? [closed]

On this paper http://www.math.cornell.edu/~kbrown/6310/computation.pdf I read : This makes it easier for you to draw Schreier graphs as you read, which I encourage you to do. …
1
vote
1answer
49 views

Composition in the category quotient

I would like to understand the accounts of P. Gabriel (http://archive.numdam.org/ARCHIVE/BSMF/BSMF_1962_90/BSMF_1962_90_323_0/BSMF_1962_90_323_0.pdf), pag 365, when he shows that t …
0
votes
0answers
7 views

integrating sigmoid function wrt probability density function

Hi, I have a random variable V with probability density g(V) and a sigmoid, or logistic, function Y=S(V). I'd like to calculate a closed-form expression for the expected value of t …
0
votes
0answers
12 views

Calculate the tendency of a set of samples

I develop an application in which i constantly get samples of heart pulse. I defined an interval of t seconds. In each t seconds I have n samples. In every interval, I want to c …
12
votes
2answers
424 views
+150

Minimum off-diagonal elements of a matrix with fixed eigenvalues

Hello, I am en engineer working in radar research. I came accross a problem I cannot seem to find math literature on it. I can ask it in two different ways. Perhaps depending on …
4
votes
3answers
1k views

Retracted Mathematics Papers [closed]

Can anyone cite an example of a mathematics paper that has been retracted? It is said that on the order of 100,000 new theorems enter the mathematics literature every year. For a …
0
votes
0answers
52 views

noetherian ring [closed]

maximal ideal generated by idempotent element why is noetherian ring ?

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