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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 ...
MrTheOwl's user avatar
  • 111
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 ...
Drew Brady's user avatar
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 \...
Neal Young's user avatar
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 ...
Pluviophile's user avatar
  • 1,608
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|/...
Mark Schultz-Wu's user avatar
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 ...
mathoverflowUser's user avatar
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. ...
total dependent random choice's user avatar
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 ...
Saúl RM's user avatar
  • 10.6k
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 $\...
Daan's user avatar
  • 141
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 ...
anon1802's user avatar
  • 131
-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 ...
Aaradhya Pandey's user avatar
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:...
Capybara's user avatar
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 ...
Sauciton's user avatar
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 ...
Stefan Perko's user avatar
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 ...
cgmil's user avatar
  • 277
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 ...
Tobias Fritz's user avatar
  • 6,406
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....
Timothy Chow's user avatar
  • 82.7k
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 ...
Qidong He's user avatar
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 ...
PontyMython's user avatar
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 ...
Martin Hairer's user avatar
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, ...
Drew Brady's user avatar
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 $G$...
SMS's user avatar
  • 1,407
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 ...
Aditya Guha Roy's user avatar
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 ...
Johnny Cage's user avatar
  • 1,561
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 ...
Francesco Bilotta's user avatar
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 $D$ ...
Drew Brady's user avatar
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<...
Francesco Bilotta's user avatar
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 ...
Francesco Bilotta's user avatar
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 ...
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 $X_n$ ...
Kaira's user avatar
  • 305
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 ...
ColorfulLion's user avatar
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 ...
Steve's user avatar
  • 101
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) > ...
dohmatob's user avatar
  • 6,853
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 ...
Jorkug's user avatar
  • 121
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 ...
Iosif Pinelis's user avatar
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 ...
Takao Hishikori's user avatar
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 $...
Greg Martin's user avatar
  • 12.8k
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 $\...
Stefan Perko's user avatar
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 ...
πr8's user avatar
  • 801
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 ...
Euclid's user avatar
  • 115
0 votes
0 answers
54 views

Reference request: "doubly empirical" measure associated to a random measure

I am considering the following type of situation. Suppose we have a random probability measure, by which I mean a probability measure on a space of probability measures atop some Polish space $X$. In ...
pseudocydonia's user avatar
4 votes
1 answer
261 views

What is the convergence rate of this "infinite monkey"-type probability?

Cross-posted from Math Stack Exchange, where it hasn’t received an answer yet: Let $S$ be a finite set and $n,m\in\mathbb N$. Consider the process $R=(R_i)_{i\in\mathbb N}$ where all $R_i$ are iid ...
Joseph Expo's user avatar
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 ...
Mushu Nrek's user avatar
0 votes
0 answers
99 views

Random walks on groups

I recently started reading Wolfgang Woess' book titled "Random Walks on Infinite Groups". In the section where he introduces Markov chains and random walks on a set $X$, he has defined a ...
Dimitri's user avatar
2 votes
1 answer
97 views

A Kolmogorov inequality for sums of contiguous subsequences

If $X_1, \ldots X_n$ are independent real-valued random variables such that $E[X_k] = 0$ and $E[X_k^2]$ is finite for each $k$, Kolmorogov's inequality gives an upper bound on $P[\max_{1\le k \le n}|...
Rob Arthan's user avatar
2 votes
1 answer
627 views

Does some published texbook take a particular approach (described here) to the transition from discrete to continuous probability distributions?

(I posted this question at matheducators.stackexchange.com and it seems to be considered an inappropriate question for that site. I don't understand why.) Imagine an introductory probability course ...
Michael Hardy's user avatar
0 votes
1 answer
102 views

Lower bounds for truncated moments of Gaussian measures on Hilbert space

Let $\mu_C$ be a centered Gaussian probability Borel measure on a real separable Hilbert space $\mathcal{H}$ with covariance operator $C$. Denote the ball with radius $r$ in $\mathcal{H}$ centered at ...
S.Z.'s user avatar
  • 505
4 votes
1 answer
283 views

Reference request: Gaussian measures on duals of nuclear spaces

I am interested in constructive quantum field theory where Gaussian measures on duals of nuclear spaces (specifically, the space of tempered distribution $\mathcal{S}'(\mathbb{R}^n)$) play a key role. ...
CBBAM's user avatar
  • 721
1 vote
1 answer
101 views

Reference for the 'Brownian Representation Formula'

I am reading a paper ('Hydrodynamics of the N-BBM Process', by De Masi, Ferrari, Presutti, Soprano-Loto) which quotes the 'Brownian representation formula' to represent the solution of a free boundary ...
user1598's user avatar
  • 177
1 vote
1 answer
344 views

Is the Borel-Cantelli Lemma applicable here? [duplicate]

Consider $(X_{n})_{n\in\mathbb{N}}$ a sequence of random variables taking values in the set $\mathbb{Z}_{\geq 0}$ where $\mathbb{P}(X_{n} = i) > 0 $ for every $i\in\mathbb{Z}_{\geq0}$ which are ...
user1234's user avatar
  • 161

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