Tagged Questions

14
votes
15answers
4k views

What are some applications of other fields to mathematics?

It is commonplace to consider applications of mathematics to other fields, especially the exact sciences. But what I would like to know about is the converse topic, namely: Wha …
3
votes
3answers
205 views

Surfaces ruled over elliptic curves

Ground field $\Bbb{C}$. Algebraic category. Elliptic surfaces are those surfaces endowed with a morphism onto some smooth curve, with generic fiber an elliptic curve. Suppose $E$ …
0
votes
1answer
27 views

Interpreting numerical double integration as a matrix multiplication

I have a convex optimization problem of finding a function Q(x,y) as below: Minimize $\int{k(x,y)Q(x,y)dxdy}$ subject to a list of constraints which are not relevant to the questi …
1
vote
0answers
15 views

Probability $k$ bins are non-empty.

The following problem arises in the analysis of Bloom filters. Consider $m$ bins and $N=nk$ balls placed uniformly at random into the bins. A query chooses $k$ bins uniformly at …
0
votes
0answers
8 views

repeated application of binomial distribution on a set of random variables

I have four solutions which are termed: A1, A2, A3, A4. These are actually the results of a searching algorithm. I know that A1 is the best solution, A2 is next to A1, A3 is next t …
1
vote
1answer
69 views

decomposition of the injective hull of a torsion free module

Let $R$ be a ring, $\Sigma$ be a multiplicatively closed subset of $R$. $M$ is an $R$-module. Denote the injective hull of $M$ by $E(M)$. $M$ is $\Sigma$-torsion if for any $m$ …
3
votes
0answers
26 views

Are small knots generic?

A knot in S^3 is small if its complement does not contain a closed incompressible surface. Is it a generic property for knots, meaning that among all knots with less than $n$ cross …
0
votes
0answers
22 views

What about weighted lens spaces (WLS) , as schemes/ algebraic varieties ?

In algebraic geometry weighted projective spaces (WPS) are very popular ! In algebraic topology , WLS have been (cohomologically at least) studied. Roughly speaking , a WPS is a …
4
votes
2answers
106 views

Are sums of the inverses of prime siblings finite?

PART I (Initial version) Let   $P$   be the set of all primes   $2\ 3\ \ldots$.   Let $$P_d\ \ :=\ \ \{\ p\in P\ :\ \exists_{q\in P}\ \ 0 < |p-q|\le d\ \}$ …
0
votes
0answers
24 views

Examples of intersections of two hypersurfaces with high-dimensional singular locus

I am interested in examples of hypersurfaces $X, Y$ defined by polynomials $F(x_1, \cdots, x_n), G(x_1, \cdots, x_n)$ respectively, so that the intersection $X \cap Y$ has a singul …
0
votes
0answers
13 views

How many geometric construction methods are there to draw the third proportional.

We know if x/y =y/z and if the straight line length for x and y are given, then how many different geometric construction methods are there to draw the straight line equals to z …
2
votes
0answers
24 views

Quotients in Sums of Rings

Suppose we are given a commutative ring R with unit-element. Now we have a composition of R as the direct product of two rings $R\cong R_1\times R_2$. It is now straight forward, …
0
votes
0answers
41 views

Finitely-generated abelian group [closed]

Let G={(a,b) in ZxZ|a= b mod10}. Proof that G is a Finitely-generated abelian group. Find a basis of G.
-1
votes
0answers
26 views

Embedded associated prime and non zero divisor

$M$ is a finitely generated $A$-module of dimension $d$ such that $G(M)$ is eqidimensional and $M$ does not have any embedded prime. Given $x\in I$ where $I$ is an ideal of $A$ an …
14
votes
6answers
2k views

Why not evaluate integrals using ODE-solvers?

Hello! I have a question about the relationship between numerical integration and the solution of ordinary differential equations (ODE). Suppose I want to evaluate the integral $I …

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