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1 vote
1 answer
308 views

Proof of the Dunford-Pettis theorem in the context of probability spaces

I'd like to know if there's a proof of the Dunford-Pettis theorem without using relatively advanced theorems of functional analysis such as Eberlein–Smulian Theorem. Since I'm only interested in ...
1 vote
0 answers
38 views

Can conditional distributions with respect to a sufficient sub-$\sigma$-algebra be represented by a single Markov kernel?

Let $(\Omega, \mathcal{F})$ be a measurable space, and let $\mathcal{P}$ be a collection of probability measures on this space. A sub-$\sigma$-algebra $\mathcal{G} \subset \mathcal{F}$ is said to be ...
3 votes
2 answers
545 views

Intensity and compensator for a jump process

Set-up and assumptions. Let $(\mathscr{F}_t, t \geq 0)$ be a right-continuous complete filtration. Let $(X_t, t\geq 0 )$ be a pure jump $\mathbb{R}$-valued process with unit jumps, that is, $$ X_t = \...
10 votes
2 answers
1k views

Simple proof of sharp constant in DKW inequality

The DKW inequality says that if $F_n$ is the empirical CDF corresponding to real-valued random variables $X_1, \dots, X_n$ distributed identically and independently from a distribution with CDF $F$, ...
2 votes
1 answer
147 views

Lower bound in the singularity of random Bernoulli matrices

Let $A_n$ be a random $n \times n$ matrix with entries in $\{-1, +1\}$. As usual, "random" here means with respect to the uniform measure over such matrices. The strong version of the ...
29 votes
3 answers
3k views

Is there a probability theory developed in intuitionistic logic?

Since Boole it is known that probability theory is closely related to logic. According to the axioms of Kolmogorov, probability theory is formulated with a (normalized) probability measure $\mbox{...
0 votes
0 answers
31 views

Looking for a citation for this simple generalization of the Markov bound to non-negative super-martingales

Does anybody know a reference for the following theorem? Theorem 1. Let $(X_t)_{t=0}^\infty$ be a non-negative supermartingale. Then, for any constant $c > 0$, the event $(\exists > t)\, X_t \...
4 votes
0 answers
219 views

Conditional distribution of steps of random walk given the sum

Set-up. Consider a random walk $S_n=\sum_{i=1}^n X_i$, where $\{ X_i, 1\leq i < \infty \} $ is a sequence of i.i.d. random variables with distribution $\mu$, $\mathbb{E}X_1 = 0$. Let $a > 0$. ...
3 votes
1 answer
405 views

Moments of a random variable related to uniform distribution on sphere

Let $u$ be taken uniformly from the unit sphere $\mathbb S^{n-1}$ and $D$ be a diagonal matrix. I'd like to find a general formula for $$ \mathbb E[(u^\top D u)^m] $$ for $m=1,2,3, \dots$, in terms of ...
3 votes
0 answers
129 views

A Talagrand inequality for the supremum of partial sums over function classes under dependence. (Reference request)

As a consequence to the Talagrand concentration inequality, it is well known that for a measurable space $(S,\mathcal{S})$ and an i.i.d. sample $X_1,...,X_n$ of $S$-valued random variables, if $\...
1 vote
0 answers
42 views

Sub-Gaussian analysis via bounded decomposition?

Let $\psi_\alpha(x) := \exp(x^\alpha)-1$. The Sub-Gaussian Norm $\lVert X \rVert_{\psi_2}$ of a random variable $X$ is defined as $$ \lVert X\rVert_{\psi_2} = \inf\{c>0\mid \mathbb{E}[\varphi_2(|X|/...
11 votes
1 answer
500 views

Uncountable families of measurable sets with pairwise positive intersections

Let $(X,\mathcal{B},\mu)$ be an arbitrary finitely additive probability measure space, let $a>0$ and let $(A_i)_{i\in I}$ be an uncountable family of subsets with measure $\geq a$. Is there an ...
1 vote
0 answers
150 views

What are alternative mathematical definitions of observers beyond Bennett and Hoffman's framework?

Motivation: This question is inspired by a talk from Avi Wigderson given on Randomness, where the idea that the randomness is in the eye of the observer is suggested. In the study of information ...
0 votes
2 answers
222 views

Reference to get quickly to modern discrete probability theory

I've had some formal training in Analysis - Functional Analysis, Basic Operator Algebra - and I've started working on probability - specifically Combinatorial Statistical Mechanics and Spin-Glasses. ...
1 vote
0 answers
74 views

Asymptotically small submatrices of random matrices

Consider an ensemble of $N \times N$ random Hermitian matrices distributed according to some unitarily invariant measure $$P(M) \mathrm{d}M = \frac{1}{Z_{N}} e^{-\mathrm{tr}[ Q(M)]}\mathrm{d}M,$$ for ...
-1 votes
1 answer
61 views

Asking for some references on correlations of joint optimization problems

Here are two problems that I am trying to understand, and it would be nice if someone could provide references on whether there is some structure theorem for these problems that have been studied in ...
8 votes
1 answer
428 views

Wishart matrices: are eigenvalues and eigenvectors independent?

Let $W = X^TX$ denote a standard Wishart matrix, i.e., where $X$ is a Gaussian random matrix with iid standard Normal entries. In this case we can write $W = U D U^T$, where $U$ is orthogonal and $D$ ...
2 votes
1 answer
79 views

What is weak convergence of random permutons?

In various papers on permutons you can find statements similar to this (see Maazoun's thesis) For any $n$ let $\sigma_n$ be a random permutation of size $n$. TFAE: $(\mu_{\sigma_n})_n$ converges in ...
3 votes
1 answer
135 views

Concentration of sample median for iid Gaussians

Let $X_1, \dots, X_n$ be iid according to $\mathcal{N}(0, 1)$, and let $M_n$ be the median of the $X_1, \dots, X_n$. I recall reading a concentration inequality for $M_n$ that was (roughly) as follows:...
2 votes
0 answers
83 views

Random time change and ergodicity

I guess it is a standard question in ergodic theory but I failed to find any reference to similar problems and I have no clue on how to tackle it. Let $(B_{t})_{t\in \mathbb{R}}$ be a standard ...
4 votes
1 answer
175 views

Looking for J.-C. Deville technical report from 2000

Yves Tillé's book Sampling Algorithms mentions several times a technical report by J.-C. Deville: J.-C. Deville (2000), Note sur l’algorithme de Chen, Dempster et Liu, Tech. rept. CREST-ENSAI, Rennes....
1 vote
1 answer
56 views

How to study the convergence of the sample mode for arbitrary probability spaces

(This is not the problem I actually care about, but an analogy with similar issues to the problem I'm actually considering.) Consider a probability space with i.i.d. random variables $X_i$ producing ...
2 votes
0 answers
205 views

When should the empirical measure of an infinite sequence be defined?

Let $(x_n)_{n \in \mathbb{N}}$ be a (deterministic) sequence of nonnegative reals, possibly even with $x_n \in \mathbb{N}$ if you prefer. Then we'd like to define the empirical measure of such a ...
4 votes
0 answers
87 views

Statistics of random Voronoi S-tessellations

Given a locally finite set of points $\{x_1,x_2,\dots\}\subset\mathbb{R}^d$, the Voronoi cell of a point $x_{i}$, denoted by $C(x_{i})$, consists of all the points in $\mathbb{R}^d$ that are closer to ...
27 votes
7 answers
9k views

Why are two "random" vectors in $\mathbb R^n$ approximately orthogonal for large $n$?

I saw that two random independent vectors are approximately orthogonal in high dimensional space. How can I prove this? And is there an intuitive explanation? Thank you.
11 votes
1 answer
950 views

Uniformization/measurable selection theorems

Let $X,Y$ be measurable spaces and $F\subseteq X\times Y$. We say that $f:X\to Y$ is a uniformization map for $F$ if $(x,f(x))\in F$ for each $x\in \pi_X(F)$ where $\pi_X$ is the left projection map. ...
1 vote
0 answers
114 views

An urn model with weighted objects and replacement

Consider the following game: In an urn, there are $K$ balls, $x_0$ of them are blue and light (mass $m_0$), $x_1$ are blue and heavy ($m_1$), $x_2$ are red and light ($m_2$), the rest $x_3$ are red ...
2 votes
1 answer
153 views

Interpolation theorem for general rough paths

In Friz and Hairer's notes on rough paths, there is exercise 2.9 which is called the "interpolation theorem". It says that if you have a sequence of rough paths $\mathbf X^n=(X^n,\mathbb X^n)...
16 votes
5 answers
3k views

Simple random walk on a locally finite graph: when is it recurrent?

I'm giving a talk tomorrow about a result in computer science which I recently proved. It's a recurrence-transience result on a random process which is related in spirit to a simple random walk. My ...
2 votes
1 answer
202 views

Strong Liouville property of virtually abelian groups

Let $G$ be a finitely generated group and let $\mu$ be a symmetric non-degenerate measure on $G$. By strong Liouville property for $(G, \mu)$, we mean that every positive $\mu$-harmonic function on $G$...
4 votes
0 answers
127 views

A "resampling identity" for the Bessel(3) process

I've come across the following resampling identity and was wondering if this is known since it seems rather natural. Take $X$ a two-sided Brownian motion conditioned to always stay below $1$. (So if ...
1 vote
0 answers
43 views

Moments on the Stiefel manifold

Let $S_{n, k} = \{V \in \mathbb{R}^{n \times k} : V^T V = I_k\}$ denote the Stiefel manifold, $1 \leq k \leq n$. Let $P \in \mathbb{R}^{n \times n}$ denote a symmetric real, positive definite matrix, ...
2 votes
1 answer
526 views

What are some (popular) references on variants of the classical gambler's ruin problem that exists in literature?

It is fascinating that the gambler's ruin problem which is so ubiquitous in modern probability theory (cf. the Levin-Peres text on Markov chain and Mixing Times) actually dates back to a letter from ...
0 votes
0 answers
149 views

Reference book for a probability course

In the next months I am planning to deliver a (more-or-less) advanced course in probability theory. My students will have had already a first encounter with discrete probability theory (discrete ...
2 votes
1 answer
177 views

Optimization over Poisson-binomial distributions

I am studying the problem of how an expected utility maximizer should optimally form a portfolio of uncorrelated Bernoullis. Fix an increasing sequence of $n$ numbers in $(0,1)$, $0<p_1<\dots<...
2 votes
1 answer
81 views

Rate of convergence of random samples wrt Hausdorff distance

Let $X$ be a compact metric space with a probability measure $\mu$. We can draw random samples $X_n = \{x_1,\cdots, x_n\}$ from $X$ using $\mu$, and I am interested in the rate of convergence of $X_n$ ...
0 votes
0 answers
85 views

When is a family of distributions "closed" with respect to minimal sufficient statistics?

As in the title, I am interested in understanding how to express the idea that a parametric family of distribution is "closed" with respect to minimal sufficient statistics. Before giving ...
2 votes
1 answer
170 views

Law of large numbers for a continuum of Bernoullis

Suppose I have a family of $n$ independent Bernoulli random variables described by a vector of parameters $(p_i)_{i=1}^n$. As it is well known, the number of successes within this family is a random ...
4 votes
0 answers
330 views

Book recommendation in functional analysis and probability

I am interested by functional analysis and probability. I would like to know if you have any books that deal with these two subjects (at a graduate level) to recommend? I'm looking for a book that has ...
3 votes
0 answers
60 views

Comparison theorem for SDEs driven by a continuous martingale

Consider the well-known comparison theorem for SDEs, versions of which appear in several textbooks, e.g., Karatzas and Shreve, Proposition 5.2.18, or Revuz and Yor, Theorem IX.3.7. The result states ...
4 votes
1 answer
122 views

Borel measures on the Martin boundary and the Poisson-Martin representation theorem

I have been studying the construction of the Martin boundary on a discrete set $X$ admitting an irreducible transient random walk $(X,P)$ from Wolfgang Woess' book titled "Random Walks on Infinte ...
0 votes
0 answers
89 views

Stein's Lemma for conditional expectation?

Let $X=(X_1,\ldots,X_d)$ be a standard normal random vector in $\mathbb R^d$, let $m:\mathbb R^d \to \mathbb R$ be a function, and let $E=E_m$ denote the expectation operator conditioned on $m(X) > ...
3 votes
2 answers
223 views

Measures with superexponential moments on finitely generated groups

Let $\Gamma$ be an infinite finitely generated group and let $\nu$ be a measure on $\Gamma$ which generates a transient random walk. I was reading this paper, and the authors prove many of their ...
2 votes
0 answers
74 views

References for a class of Banach space-valued Gaussian processes

Let $E$ be a separable Banach space, consider a centered $E$-valued Gaussian process $\{x_t,t\ge 0\}$ that satisfies \begin{equation} \mathbb{E}\phi(x_s)\psi(x_t)=R(s,t)K(\phi,\psi),\quad \phi,\psi\in ...
4 votes
1 answer
204 views

How probability-rich is the $\sigma$-algebra generated by a sequence of sets? (Sierpiński's theorem on non-atomic measures without using the AoC.)

$\newcommand\F{\mathcal F}\newcommand\si{\sigma}\newcommand\Om{\Omega}\newcommand\ep{\varepsilon}$Let $p\in(0,1)$ and let $(\Om,\F,P)$ be a probability space. Let $(A_n)$ be a sequence in $\F$ such ...
1 vote
0 answers
43 views

Definition of "interval of continuity" for function defined on sets

At the beginning of Chapter 8 of Kubilius's Probabilistic Methods in the Theory of Numbers, the author defines $Q=Q(E)$ to be a completely additive nonnegative function defined for all Borel subsets $...
0 votes
0 answers
37 views

Compatibility of 2-copulas

An $n$-copula is the joint distribution function of a distribution on $[0,1]^n$ with uniform marginals. A family of 2-copulas $(C_{i,j})_{i<j\leq n}$ is compatible if there exists an $n$-copula $\...
1 vote
0 answers
92 views

Modulus of Continuity, Heat Flow, and Derivative Estimates

Given $f : \mathbf{R}^d \to \mathbf{R}$, define $P_t f$ by \begin{align} (P_t f)(x) = \mathbf{E} \left[ f (x + \sqrt{t} G) \right], \end{align} where $G \sim \mathcal{N} (0, I_d)$ is a standard ...
0 votes
0 answers
92 views

MDP Average Reward independent of Initial State

Consider a Markov Decision Process where the state space $S$ and the action space $A$ are continuous and compact. In state $s$, if action $a$ is chosen and the next state becomes $s'$, the ...
4 votes
0 answers
80 views

Does this filtration have a name?

In the context of Ethier&Kurtz Markov Processes: Characterization and Convergence (Chapter 4, equation (3.2)) as well as the two papers Martingale problems for conditional distributions of Markov ...

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