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Integral over the space of $p$-adic matrices

$\DeclareMathOperator\Mat{Mat}$Let $\mathbb{F}$ be a non-Archimedean local field. Let $\mathcal{O}$ be its ring of integers with a uniformizer $\pi$. Let $|\cdot|\colon \mathbb{F}\to \mathbb{R}$ be ...
asv's user avatar
  • 21.1k
3 votes
1 answer
136 views

Solving a recursion for polynomials defined by a matrix product

Define the polynomial $p_n(X) \in \mathbb{Z}[X_1,...,X_n]$ as the top left entry in $A^n$ for the $(d \times d)$ matrix \begin{align*} & A = \left(\begin{matrix} X_1 & \dots & \...
Tardis's user avatar
  • 1,077
2 votes
0 answers
49 views

Constructing a cyclic extension $L$ with given local behavior of a global field $K$ such that $L$ is normal over a subfield $F$ of $K$

Let $F$ be a global field without real places (that is, a function field or a totally imaginary number field). Let $K/F$ be a cyclic extension of degree $n$. Let $S$ be a ${\rm Gal}(K/F)$-invariant ...
Mikhail Borovoi's user avatar
14 votes
1 answer
1k views

Hilbert's sixth problem and QFT description

The Wikipedia entry on Hilbert's sixth problem about QFT description is “Since the 1960s, following the work of Arthur Wightman and Rudolf Haag, modern quantum field theory can also be considered ...
XL _At_Here_There's user avatar
1 vote
0 answers
66 views

How to know the character table of the twisted group algebra of the symmetric group $S_4$

Given the character table of its Schur cover group, is there a way to obtain the character table of twisted group algebra from that? I am particularly interested in the symmetric group $S_4$.
Wenxia Wu's user avatar
1 vote
0 answers
63 views

Fitting a product into the quintuple or Jacobi triple product

The Rogers-Ramanujan functions fit nicely into the QPI or JTP. In fact we have that $$(q^{5};q^{5})_{\infty}(q,q^{4};q^{5})_{\infty}=\sum_{n=-\infty}^{\infty}(-1)^{n}q^{\frac{(5n^{2}-3n)}{2}}$$ and we ...
Jay's user avatar
  • 11
0 votes
0 answers
31 views

Justification for the "derivative kernel" for a Gaussian Process

In general, it is fairly well established that a method of including derivative information into a a Gaussian Process is to: Extend the training vector with derivative information $[y, \delta{y}_1, .....
HaoZeke's user avatar
  • 101
5 votes
0 answers
75 views

Reciprocity for algebra objects in two algebraic categories

I think this question Compact Hausdorff and C^*-algebra "objects" in a category. shows that there is no reciprocity between categories of algebra-objects of two algebraic categories. So, ...
Nik Bren's user avatar
  • 499
6 votes
0 answers
146 views

Complexity of transfinite 5-in-a-row and other games

Suppose that 5-in-a-row is played on an infinite board, and after an infinite number of moves, if no one won yet and there is an empty square, the game just continues. At limit steps, it is the first ...
Dmytro Taranovsky's user avatar
5 votes
0 answers
79 views

When a compact subset of a TVS can be continuously projected on a closed linear subspace?

Let $V$ be a (Hausdorff) topological vector space, $W\subset V$ a closed linear subspace, $X\subset V $ a compact. (Q): When there is a continuous map $P:X\to W$ such that $P(x)=x$ for every $x\in X\...
Pietro Majer's user avatar
  • 56.5k
13 votes
0 answers
438 views

Is there a simple proof that representations of GL(n,k) are determined by their restriction to diagonal matrices?

Let $k$ be a field of characteristic zero. The general linear group $\mathrm{GL}(n,k)$ has a subgroup $\mathrm{D}(n,k)$ consisting of invertible diagonal matrices. These are linear algebraic groups ...
John Baez's user avatar
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2 votes
0 answers
82 views

Bateman-Horn-type generalization of the Goldbach conjecture

The Bateman-Horn conjecture is a generalization of the twin prime conjecture that roughly states that given a set $S=\{f_1, \dots, f_m\}$ of irreducible polynomials with integer coefficients, there ...
Ben's user avatar
  • 151
2 votes
0 answers
31 views

0-1 knapsack problem with additional capacity

The 0-1 knapsack problem maximizes the profits of items under a capacity constraint (let's call this capacity $C$). I am interested in an augmented setting where the algorithm is permitted to use a ...
Titan's user avatar
  • 21
0 votes
0 answers
66 views

Gibbs Priors form a Martingale

I am working on adapting variational inference to the recently developed Martingale posterior distributions. The first case, which reduces the VI framework to Gibbs priors, is proving hard to show as ...
BayesRayes's user avatar
6 votes
0 answers
70 views

Error estimates for projection onto the Wiener chaos expansion for stochastic Sobolev spaces (stochastic Rellich–Kondrachov theorem)

Let $n$ be a positive integer, $s\in \mathbb{R}$, $(\Omega,\mathcal{F},(\mathcal{F}_t)_{t\ge 0},\mathbb{P})$ be a filtered probability space whose filtration supports and is generated by an $n$-...
ABIM's user avatar
  • 5,019
1 vote
2 answers
233 views

Joint moments like $\tau(XYXYXY)$ in terms of individual moments of free variables $X,Y$

Terry Tao RMT book has the following formula for joint moment of freely independent random variables $X,Y$ in Section 2.5 $$\tau(XYXY)=\tau(X)^2\tau(Y^2)+\tau(X^2)\tau(Y)^2-\tau(X)^2\tau(Y)^2$$ ...
Yaroslav Bulatov's user avatar
3 votes
0 answers
142 views

Homotopy type theory for semantics

It looks like I have been building up a theory that might require looking closely at Homotopy Type Theory vs. Category Theory with respect to semantics. I am considering two types of semantics that ...
Ben Sprott's user avatar
  • 1,281
3 votes
1 answer
108 views

Different notions of equivalences of $\mathcal{O}$-monoidal $\infty$-categories

I am currently reading Higher Algebra by Jacob Lurie and I have a question regarding equivalences of $\mathcal{O}$-monoidal categories. Let $\mathcal{O}$ be an $\infty$-operad. Suppose that I have two ...
YjL's user avatar
  • 41
3 votes
0 answers
73 views

A stochastic matrix $B = \lambda(\lambda I - A)^{-1}$ such that $B-B^2$ has a non-negative diagonal

I apologize if this is too elementary a question, but I have not been able to make much progress. Consider a real matrix $A$ with $A_{ij} >0$ for $i \ne j$ and $\sum_{j} A_{ij} = 0$ for each $j$. ...
user133281's user avatar
4 votes
0 answers
125 views

On adelic integration

$\DeclareMathOperator\GL{GL}$This question might be beyond naive but I really can't find it nor figure it out. It's related to explicit idelic integration as opposed to just bounding its values. Let $...
MEEL's user avatar
  • 141
1 vote
0 answers
22 views

Inner product of signatures of piecewise linear paths

It is a well-know observation that, given two points $x_1,x_2 \in \mathbb{R}^d$, the path signature associated to their linear interpolation is given by the tensor exponential. Precisely, if $\Delta x$...
Gaspar's user avatar
  • 81
0 votes
2 answers
126 views

Cauchy's functional multiplicative equation on the unit interval

This question might be trivial, but I didn't find a clean reference and have not attempted to prove it myself yet: Let $f:[0,1]\rightarrow [0,1]$ be a continuous and monotonic function such that $f(0)=...
Pedram's user avatar
  • 97
0 votes
2 answers
57 views

Nondegeneracy of dominant singular value and positivity of dominant singular vector of connected nonnegative matrix

Call a (not necessarily square) nonnegative matrix $M$ connected if there do not exist permutation matrices $P$ and $Q$ such that $PMQ=\begin{pmatrix}A&0\\0&B\end{pmatrix}$ for some $A$ and $B$...
David Bevan's user avatar
1 vote
0 answers
49 views

Frobenius acting by autoequivalence on $\text{Isoc}(X/K)$

Let $X_k$ be a smooth quasiprojective scheme over a finite field $k$. Let $X_K$ be a smooth lift of $X_k$ to the fraction field of the Witt ring of $k$, which I denote by $K$. In various papers I read ...
kindasorta's user avatar
  • 1,473
0 votes
1 answer
90 views

Criterion for Ramification of ray class field $K(\mathfrak{p})$ in $\mathfrak{p}$

The context: We consider ideal theoretic formulation of global class field theory of a number field $K$ and in following all used terminology I'm going to use is adapted from these notes: https://math....
user267839's user avatar
  • 5,948
4 votes
0 answers
136 views

Coloured Jones polynomial at 4th root of unity and Arf invariant

Looking at the link invariants of $\operatorname{SU}(2)$ Chern-Simons theory, if we take the coloured Jones polynomial of a knot K, say $J_N^K$ at fundamental representation $N=2$, then we get the ...
hopftype's user avatar
9 votes
0 answers
212 views

Existence of $1$-separated and $(1-\varepsilon)$-dense set in metric spaces

Is it know which metric spaces $M$ do have the following property: there is $\varepsilon>0$ and a maximal $1$-separated set which is $(1-\varepsilon)$-dense? In other words, when does at set $S\...
Christian's user avatar
  • 779
1 vote
0 answers
121 views

Can't parse a statement in an article on coalgebras and umbral calculus

This question is cross-posted from MSE. I am reading Nigel Ray's "Universal Constructions in Umbral Calculus" (1998, published in "Mathematical Essays in Honor of Gian-Carlo Rota", ...
Daigaku no Baku's user avatar
1 vote
0 answers
81 views

Factorial surfaces and smoothness

It is well-known that normal curves are smooth. Moreover, a UFD of Krull dimension one is regular. Is there any higher-dimensional analog? For example, given a normal projective surface $S$ over $\...
Jooh's user avatar
  • 111
3 votes
1 answer
195 views

A criterion for numerically trivial line bundle

Let $X$ be a projective smooth variety, $D$ a Cartier divisor on $X$. If for any Cartier divisor $B$ on $X$, $\mathcal{O}_X(B)$ and $\mathcal{O}_X(B+D)$ have the same Euler characteristic $$\chi(X,\...
Junpeng Jiao's user avatar
3 votes
0 answers
70 views

An isomorphic classification of non-associative division octonion algebras

A division octonion algebra over a field $F$ is a $8$-dimensional unital non-associative algebra $A$ over the field $F$, endowed with a quadratic form $N:A\times A\to F$ such that $N(xy)=N(x)N(y)$ and ...
Taras Banakh's user avatar
  • 40.8k
2 votes
0 answers
53 views

When does an algebraically independent set "satisfy Noether normalization"?

Let $k$ be a field, $A$ a finitely generated $k$-algebra. By Noether normalization, we know that there exists a finite morphism of $k$-algebras $\varphi : k[x_1, \ldots, x_d] \hookrightarrow A$, with $...
Adelhart's user avatar
  • 227
2 votes
0 answers
93 views

Is the Schwartz space a tame Frechet space?

I ran into the following definition of tame Frechet spaces and Nash-Moser therem. It says that the space of smooth functions on a compact manifold is tame Frechet. However, I wonder if The Schwartz ...
Isaac's user avatar
  • 2,727
1 vote
0 answers
44 views

Extension operator maps which fractional Sobolev space to $W^{p,s}(R)$

Let us assume we have the following extension operator: $$ \operatorname{ext}_R^\sigma u= \begin{cases} u(x) & \text{if }x \in (0,T)\\ u(0) & \text{if }x \in(0,T)^c. \end{cases} $$ We ...
Fractional analysics's user avatar
1 vote
0 answers
153 views

Are there any relations between perverse t-structure (cohomologies) and standard t-structure (cohomologies)?

I'm reading the Corollary 3.2.3. in Exponential motives by J. Fresan and P. Jossen. The authors use the following statement in the proof of Corollary 3.2.3: let $C$ be any object in the derived ...
Mathstudent's user avatar
0 votes
1 answer
55 views

Does point process ordering ever imply conditional intensity ordering?

Let $N$ and $N'$ be regular/non-explosive point processes on $[0,\infty)$. I will take the view that these are collections of random arrival times: $N=(t_n)_{n\in\mathbb N}$ and $N'=(t_n')_{n\in\...
jdods's user avatar
  • 213
12 votes
1 answer
368 views

Partition into antichains

I've read that the following statement is a result of Balcar, but I am unable to find a reference or a proof: Theorem: If $\kappa\ge \lambda$ are infinite cardinals, then $[\kappa]^{<\lambda}$ can ...
Lajos Soukup's user avatar
  • 1,415
2 votes
1 answer
136 views

Upper bound of a product of sines

Consider the function $$ f_n(t)= \prod_{1 \leq k \leq n-1,\\ \gcd(k,n)=1} \sin\Big(t-\frac{k \pi}{n}\Big),\quad t \in [0,\pi].$$ I wonder whether it is possible to compute some nontrivial upper ...
AgnostMystic's user avatar
0 votes
0 answers
100 views

What are the primitive notions and axioms in model theory? [migrated]

I know every theory has its primitive notions and axioms. Now I am reading Basic Model Theory, and there is no term or sentence referred as to a primitive notion or an axiom. But, I think I know that ...
Wenchuan Zhao's user avatar
-2 votes
0 answers
132 views

Elimination over $\mathbb F_p[x,y]$

Let $p$ be a prime. Consider the two independent modular equations: $$a_1x^2+b_1y^2+c_1xy\equiv d_1\bmod p$$ $$a_2x^2+b_2y^2+c_2xy\equiv d_2\bmod p$$ Is it possible to extract the common roots $(x,y)\...
Turbo's user avatar
  • 13.7k
8 votes
1 answer
335 views

Is the Whitehead bracket $\pi_{p}(X)\otimes \pi_{q}(Y)\to \pi_{p+q-1}(X\vee Y)$ injective?

Let $X$ and $Y$ be finite CW-complexes and $p,q\geq 2$. The Whitehead bracket induces a homomorphism $\pi_{p}(X)\otimes \pi_{q}(Y)\to \pi_{p+q-1}(X\vee Y)$, $\alpha\otimes \beta\mapsto [\alpha,\beta]$....
J.K.T.'s user avatar
  • 487
1 vote
1 answer
173 views

Hilbert scheme of points on an arithmetic surface

$\DeclareMathOperator\Hilb{Hilb}\DeclareMathOperator\Spec{Spec}$Let $X$ be a smooth surface over a field $k$. Fogarty proved that the Hilbert scheme of points $\Hilb^n(X)$ is regular. My primary ...
Stephen McKean's user avatar
1 vote
2 answers
372 views

What is the proper name for this "tersest path" problem in Infinite Craft?

The web game Infinite Craft gives you a starting set of elements $V_0\subset V$ and a mapping $E$ of type $V\times V\rightarrow V$. In fact, $F$ is commutative: $E(v_a,v_b) = E(v_b,v_a)$. So another ...
Quuxplusone's user avatar
3 votes
0 answers
47 views

One parameter subgroups of reductive algebraic groups

If I have a reductive algebraic group $G$ defined over a non-archimedean local field $F$. We can define a one-parameter subgroup to be a group homomorphism from $G_{m}$ to $G$. I was wondering, if I ...
Ekta's user avatar
  • 63
7 votes
1 answer
120 views

Is it possible for the dihedral angles of a polyhedron to all grow simultaneously?

(Originally on MSE.) Suppose $P$ and $Q$ are combinatorially equivalent non-self-intersecting polyhedra in $\mathbb{R}^3$, with $f$ a map from edges of $P$ to edges of $Q$ under said combinatorial ...
RavenclawPrefect's user avatar
2 votes
1 answer
231 views

If Kolmogorov continuity criterion gives the optimal Hölder regularity then does the process have all moments?

Although very useful in the Gaussian (or other infinite moment) setting, Kolmogorov continuity criterion is non optimal in the finite moment setting. For example, let $X(t)=Zt$ where $Z$ is a random ...
user479223's user avatar
  • 1,250
3 votes
1 answer
184 views

Some questions about induced subgraphs of the directed hypercube graph

Let $Q^n$ be the hypercube graph in $n$ dimensions. Hao Huang famously showed that any induced subgraph on more than $2^{n-1}$ must have maximum degree $ \geq \sqrt{n}$. It is also known that this ...
Agile_Eagle's user avatar
3 votes
0 answers
69 views

Norm estimate for parabolic SPDE solution

When $X$ satisfies $${\rm d}X_t=\varphi_t{\rm d}t+\Phi_t{\rm d}W_t$$ on a Hilbert space $H$, where $W$ is a $Q$-Wiener process on a Hilbert space $U$, we know by the Ito formula that $$\|X_t\|_H^2-\|...
0xbadf00d's user avatar
  • 161
6 votes
1 answer
375 views

Tame-Wild dichotomy; why can't tame algebras be wild?

I would like to understand the Tame-Wild dichotomy, and in particular why an algebra cannot be tame and (semi-)wild at the same time. I've looked in the papers by Drozd and Crawley-Boevey [D80, CB88]. ...
Jacob FG's user avatar
  • 477
2 votes
0 answers
46 views

Smoothness of the Fréchet Function

Let $M$ be a compact Riemannian manifold and $d$ be the induced distance function. Suppose $\mu$ is a probability measure on $M$ with continuous density. The Fréchet function is defined as $$ F(x) = \...
Yueqi's user avatar
  • 21

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