-2
votes
0answers
18 views

Drawing graph with some different metric values [closed]

I have some metrics but all of them have different values. Some are decimals, some are integers and some are large numbers. Assume the metrics are (average values): - metric1 - 1500 - metric2 - 0....
2
votes
1answer
64 views

Version of Donsker-Invariance-Principle

Assume we have a Levy process $(X_t)_{t\geq 0}$ with a finite second moment for all $t>0$. For simplicity, say $\operatorname{Var}\left[X_1\right]=1$. Let $\tilde{X}_t:=X_t-t\cdot E\left[X_1\right]$...
-2
votes
1answer
117 views

Action of $\mathbb{Z}/3\mathbb{Z}$ on $P^{1}$ [closed]

I am reading from the book Topics in Galois theory by Serre. I have the following question , take $G=\mathbb{Z}/3\mathbb{Z}$. The group $G$ acts on $P^1$ by $$\sigma x\;=\;1/(1-x)$$ where $\sigma$ ...
0
votes
1answer
153 views

Characters and Galois stability

Let $G$ be a finite abelian group and $\widehat{G}$ the character group. Let $S \subset \widehat{G}$ be a Galois-stable subset i.e. if $\chi \in S$, then the Galois conjugates $\chi^{\sigma} \in S$ ...
-1
votes
0answers
22 views

Equality of sum of fractions implies correspondence of terms [closed]

I am working in a theorem of Jhonson and Newman about cospectrality and got stucked un this claim. can you help me? $a_i$ and $b_i$ are non negative numbers, $z\in\mathbb{C}$ and $d_i \neq d_j$ for $...
0
votes
1answer
61 views

On some examples of critical families

I'm reading the book on Injective choice functions by Holz, Podewski and Steffens, and I find it to be at the same time well written and quite difficult. It has almost no examples - and in quite a few ...
4
votes
1answer
147 views

Does complex multiplication for higher dimensional abelian varieties give some generalization of class field theory?

I am currently learning some aspects of the theory of complex multiplication for elliptic curves, and the relationship with class field theory. As I understand it, there is a very special class of ...
2
votes
1answer
74 views

Minimize matrix distance to tensor product

Minimize the following function: $ f(V) = || V \otimes V - U_1 \otimes U_2 ||$ where $U_1, U_2 \in SU(n)$ are fixed and we minimize over all $V \in SU(n)$. The norm is from the trace inner product. ...
0
votes
0answers
48 views

A generalization of the Tucker circle theorem and the Thomsen theorem associated with a conic

I gave a generalization of the Tucker circle theorem and the Thomsen theorem at here. Now, I give a more generalization of these theorems as following: Problem: Let $A_1A_2A_3A_4A_5A_6$ be a hexagon, ...
0
votes
0answers
34 views

Software for matching theorems to inputted conditions/hypotheses

Many times I find myself going through analysis books, wikipedia and papers, looking for what is known for my functions/objects at hand. So is there any software that at least tries to move in that ...
3
votes
1answer
114 views

Does this PDE have a name?

I'm looking for any and all information that might be known about the following second-order PDE for one function $u(x,y)$: $ u_{xy} = u_x e^u + u_y e^{-u} $ e.g., Does it have a name? Is it known ...
6
votes
2answers
95 views

Uniform Concentration Bounds on Weighted Sum of i.i.d. Bernoulli Random Variables

Let $\delta_1,...,\delta_n$ be $n$ independent identically distributed Bernoulli random variables with $\mathbb{P}(\delta_1=1)=p$. We consider a set $\Omega = \{\mathbf{a}:=(a_1,...,a_n)~|~a_i\in [0,c/...
7
votes
3answers
196 views

When can the Cayley graph of the symmetries of an object have those symmetries?

Let $P$ be an object in $\mathbb{R}^n$ with symmetry group $G$. Let $C$ be the a Cayley graph of $G$. When can $C$ be embedded in $\mathbb{R}^m$ so that the embedded graph has the same symmetry ...
2
votes
0answers
85 views

example of fuchsian groups acting on 2-sphere by G. Martin

Currently I am reading a paper "Infinite group actions on spheres" by Gaven Martin. I am a first year graduate students and I got lots of questions, so one of them is about the following example: (...
10
votes
3answers
279 views

How to sample a uniform random polyomino?

A polyomino is formed by joining finitely many unit squares edge to edge. It may be regarded as a finite subset of the regular square tiling with a connected interior. In particular, for us, ...
29
votes
2answers
579 views

$x_1 = 2$, $x_{n + 1} = {{x_n(x_n + 1)}\over2}$, what can we say about $x_n \text{ mod }2$?

This question was asked on MathStackexchange here, but there was no answer, so I am asking it here. Let$$x_1 = 2, \quad x_{n + 1} = {{x_n(x_n + 1)}\over2}.$$What can we say about the behavior of $x_n ...
-4
votes
0answers
95 views

Finite groups are isomorphic [closed]

For two finite groups $G_1, G_2$ if for every integer $n\geq 0$, $|G_1^n| = |G_2^n|$, then is it true that $G_1\cong G_2$? By $G^k$ we mean set $\{g^k|g\in G\}$.
5
votes
2answers
193 views

Criterion for being reflexive via Ext

In this question it was claimed that if a module $M$ over a noetherian domain $R$ satisfies $\rm{Ext}^i(M,R)=0$ for $i=1,2$, then $M$ is reflexive. Is this true? Does someone know a reference or a ...
-3
votes
0answers
138 views

How to explain the subject Operator Algebra to dummies? [closed]

I have to appear for an interview to pass the requirements of AI instructor. I have to explain what is operator algebra which is my subject to Professors of Department of Second Language Studies. Any ...
-4
votes
0answers
27 views

summation of operators in Lp space [closed]

How can we find upper bounded for following term in L∞ space? the term is : ||u_1 C_(φ_1 )+ u_2 C_(φ_2 )|| according to this point that the terms u_1 C_(φ_1 ) and u_2 C_(φ_2 ) are not bounded. ...
1
vote
0answers
54 views

Reference on Probability theory on functional spaces (in special Hilbert spaces)

Currently, I am working on some sort of stochastic optimization problems defined over function spaces. I am familiar with standard probability theory (R. Durrett, ''Probability: Theory and Examples")...
0
votes
0answers
67 views

(∀x.(p(x)⇒∀x.p(x)) )= ((∃x.p(x))⇒(∀y.p(y)))? [closed]

In dealing with my homeowrk, someone has told me ∀x.(p(x)⇒∀x.p(x)) could be transformed to (∃x.p(x))⇒(∀y.p(y)) However, intuitively, this doesn't make sense to me, could anyone give me a ...
1
vote
0answers
109 views

Vector bundles and equivariant vector spaces

It seems commonly accepted that most of the results of equivariant geometry for vector spaces yield analog result for vector bundles. In so far as I understand it, the reason for that is the ...
-1
votes
1answer
155 views

When the Ratio of Two Factors is a power of $2$ (i.e. $\lfloor{\frac{a}{b}}\rfloor = 2^{s-2}$)

We can write, $n!= 2^s \times a \times b$ where $gcd(a,b)=1$ and $2^{s+1} \nmid n!$. Problem: Is there infinite number of $n$ when $\lfloor{\frac{a}{b}}\rfloor = 2^{s-2}$? Question: 1.How ...
0
votes
0answers
68 views

Variation on stones in buckets

This is a spinoff, see Collecting stones in n buckets. Frankly speaking my only motivation is that I became curious: what happens if one redistributes the stones into the same buckets? More ...
2
votes
1answer
170 views

Kummer extension of Galois modules

Let $k$ be a field of characteristic $p \geq 0$, $n$ an integer prime to $p$, and $x$ an element of $k \setminus \{0, 1\}$. I have read that the $n^{th}$ root of $1-x$ gives rise to a Galois module $E$...
3
votes
0answers
135 views

Schemes locally of finite type

Let $k$ be a field. Does it exist an irreducible and separated $k$-scheme locally of finite type which is not of finite type?
-1
votes
0answers
24 views

Multi-objective optimization for large matrices

I have a large matrix 102400 x 600 to optimize for two different criteria (maximum likelihood over a large dataset and another more complicated one). In practice, it represents a factors loading ...
1
vote
0answers
88 views

Is this a new type of convex pentagonal tiling? [duplicate]

The following pentagon produces a tiling that does not appear to belong to any of the existing 15 categories: Here's the tiling: Specifically, it is not Type4 or Type6 because those are edge-to-...
0
votes
0answers
42 views

Conditions for supremum and conditional Expectation to commute

I am working with a continuous process $Y_t$ generating the filtration $(F_t)$ and have (for simplicity) two stopping times $\tau_1$ and $\tau_2$ such that $\tau_2 \leq \tau_1$ and $U:\Bbb R\...
5
votes
2answers
245 views

Is there any formula to find number of Pythagorean triplets between two integers 2 and j, j>2?

Given $j \geq 5$, is there a formula for the number of Pythagorean triplets $(a, b, c)$ satisfying the constraint that $a, b, c \leq j$? There exists at least one Pythagorean triplet for $j\geq5$; ...
0
votes
0answers
43 views

How many different solutions does this cube puzzle have?

I designed a 4x4x4 soma cube in AutoCad and then built it with wood cubes. Now I want to know how many different solutions there are for it. Similar to the Bedlam Cube, there are twelve pentacube and ...
6
votes
0answers
188 views

Tree property using side conditions

The following problems were asked during the high and low forcing workshop: Question 1. Can one force tree property at $\kappa^{++}$ for $\kappa$ singular using side conditions? Question 2. ...
2
votes
3answers
320 views

Find a distinct postive integer solution to this $xyzw=504(x^2+y^2+z^2+w^2)$ diophantine equation

Following problem though not a research problem if $x,y,z,w$ are postive integers,and such $$xyzw=504(x^2+y^2+z^2+w^2)$$ such example $(x,y,z,w)=(21,63,84,84)$ hold, Now My problem there exist ...
2
votes
1answer
165 views

Reference - Generalized Hodge conjecture for triangulated motives

GHC for triangulated motives: The Hodge conjecture holds and an object $\rm M \in Dmg$ is effective if and only if its Hodge realization is effective. I would like to know some references on GHC ...
0
votes
0answers
93 views

Splitting the Tits algebras of a anisotropic group

Assume we are given an anisotropic algebraic group $G$ over a field $k$, having non trivial Tits algebras (i am interested in the $E_7$ adjoint cases). Question: Is it possible that there exists a ...
2
votes
2answers
184 views

approaches to Apollonius circle problems

I've been looking for solutions to finding the set of circles tangent to two other circles. one circle can be inverted to a line, but two circles can be mapped to a line and a circle or equivalently ...
2
votes
1answer
104 views

An upper bound for the number of prime numbers in non-linear progressions

Let $f(x)$ be a non-linear polynomial over $\mathbb{Z}$. Consider the following sum $\pi_f(x):= \#\{y: y< x \text{ and } f(y) \text{ is prime} \}$. Can we get an upper bound for $\pi_f(x)$?
11
votes
2answers
278 views

Is a C*-algebra with an isomorphic predual a von Neumann algebra?

It is well-known that a C*-algebra $A$ is a von Neumann algebra if and only if it has an isometric predual, that is, if and only if there exists a Banach space $X$ such that $A$ is isometrically ...
3
votes
0answers
92 views

Is there a schema category for hyperstructures?

I am completely fascinated by Niels Baas' notion of hyperstructures, chiefly because I can see how such gadgets could be used in modeling both biological and social systems, or other evolutionary ...
4
votes
1answer
158 views

Does every smooth manifold admit a metric with bounded geometry and uniform growth?

Let $M$ be a smooth manifold, $g_M$ a Riemannian metric, and consider for $x\in M$ the volume growth function, $gr_x$ that maps $r>0$ to the volume $vol_{g_M}(B(x,r))$. My interest is to see ...
0
votes
0answers
30 views

Reasons for $\alpha>-\frac{1}{2}$ constraint in texts regarding Gegenbauer polynomials $C^{(\alpha)}_k(x)$

In texts regarding the Gegenbauer polynomials $C^{(\alpha)}_k(x)$, I often see the constraint $\alpha>-\frac{1}{2}$ alongside definitions and identities. I understand that the orthogonality ...
-4
votes
0answers
28 views

calculating moments in a table [closed]

I am trying to calculate the moments in a data list position data 1 15 2 22 3 5 4 2 5 1 to find out where in the list is ...
5
votes
1answer
244 views

Subgroup schemes of $\mathbb{A}^n$

Let $R$ be an integral $\bar{k}$-algebra of finite type. Let $V(I) \subseteq \mathbb{A}_R^n$ be a reduced (closed) subgroup scheme such that $V(I)\backslash \{0\} \neq \emptyset$ and the $\mathbb{G}_m^...
9
votes
2answers
498 views

congruent number problem [closed]

I am studying the congruent number problem and I heard that there is a paper by Kazuma Morita which claims to solve this problem from my colleague. I saw the paper on his homepage but it is very ...
0
votes
0answers
25 views

Application of Lemma in Iterated Expectation [on hold]

I was reading the following paper: InfoGAN. I cannot figure out, how on page 4, Lemma 5.1 was applied in the following lines: $$\mathbb{E}_{c \sim P(c), x \sim G(z,c)}[\log Q(c|x)] = \mathbb{E}_{x \...
2
votes
0answers
112 views

Chern character (form) of a Gauss-Manin connection

Consider the trivial fibration $\mathbb{T}^2\to\mathbb{S}^1$, where $\mathbb{T}^2$ is the two-torus. Denote by $\mathbb{C}\to\mathbb{T}^2$ the trivial line bundle over $\mathbb{T}^2$, and equip it ...
2
votes
0answers
25 views

Metrics on the group of unimodular polynomial matrices

The group of unimodular matrices $\mathbb{U}[s]^{n\times n}$ is given by the set of $n\times n$ square (real) matrix-valued polynomials $\mathbb{R}[s]^{n\times n}$ which admit a polynomial inverse. ...
3
votes
1answer
40 views

the structure on the value group sort of a C-minimal field

Let $K$ be an algebraically closed valued field which is $C$-minimal, as defined, for example, in this article. Examples include pure algebraically closed valued fields, as well as Lipschitz and ...
3
votes
1answer
186 views
+50

Lie algebra of invariant polynomials or invariant smooth functions

Is there a symplectic structure on $M_{2n}(\mathbb{R})$, not necessarily with constant coefficients, such that the space of smooth invariant functions, those smooth functions $f:M_{2n}(\mathbb{...

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