Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
Theory and applications of probability and stochastic processes: e.g. central limit theorems, large deviations, stochastic differential equations, models from statistical mechanics, queuing theory.
2
votes
Accepted
Minimax optimal multiple hypothesis test
Deterministic $\Psi$ is bound to fail. You must randomize. Consider three probability measures supported on $\{1,2\}$. A deterministic $\Psi$ will have only two of the measures in its image. The adver …
7
votes
Accepted
Diameter bound for graphs: spectral and random walk versions
The conjectured inequality is false in General.
Proof: Let $\ell=\lfloor n^{1/2}/2 \rfloor$ and let
$G_1,G_2,\dots,G_\ell$ be disjoint cliques of size $\ell$. Let $K$ be a clique on $n-\ell^2 >n/2$ …
4
votes
Random spanning trees probability problem
The connection between uniform spanning trees $T$ and stable polynomials used in Fedor Petrov's answer is indeed beautiful, and yields a sharp bound. I want to mention that the slightly weaker bound o …
2
votes
Accepted
Asymptotic properties of weighted random walks / infinite convolutions of random variables
Let $(X_n)_{n\in\mathbb{N}}$ be i.i.d. real random variables and let $0<c<1$.
Then the following are equivalent:
(a) There exists $r>0$ such that $P(|X_k|>e^{rk} \; \, \text{infinitely often} )=0$.
( …
1
vote
General definition for $k$-dependence of a family of sub-$\sigma$-algebra
One possible definition is to assume a graph structure on the index set, where the maximal degree is $k$. Then you assume that every algebra $\mathcal{F}_i$ is independent of the join of the algebras …
3
votes
Forgery theorem: the Brownian motion stays close to any curve with positive probability
There was part of the hint that you ignored, namely using Levy's construction. To add some detail, the approximation of $S^{n}$ by BM is done recursively in each dyadic interval, rather than globally. …
11
votes
Accepted
Concentration bounds for martingales with adaptive Gaussian steps
Observe that $X_n=X_{n-1}(1+Z_n)$ where $\{Z_k\}_{k \ge 1}$ are i.i.d. standard normal. Hence to analyze the asymptotic distribution of $|X_n|$, pass to logarithms, to get $$\log(|X_n|)= \log(|X_1|) + …
2
votes
Accepted
Maximum of a sequence is $o(\sqrt{n})$
First suppose that hypotheses (a) and (b) hold. I will write $w_{i,n}$ instead of $w_i^n$ for clarity.
Given $\epsilon>0$, the Monotone convergence theorem implies that there exists $M$ such that $ …
2
votes
Polynomial time mixing Markov chain for multimodal distribution
As noted in the comment by James Martin, some assumption is needed on the Markov chain, e.g., that each step of the chain can be implemented on a Turing machine in polynomial time.
The Swendsen-Wang …
5
votes
Accepted
What is the exact definition of a sharp transition?
The parameters $p_n$ are not arbitrary numerical parameters. They represent the expectation of one binary variable in a product space. Changing them additively is very different from changing the powe …
1
vote
Show that the set of strictly stationary, mean zero and finite variance stochastic processes...
Yes, $\mathcal{P}$ is closed in the spaces
\begin{equation}
\mathcal{P}_1:=\left\{ X = (X_t)_{t \in \mathbb{Z}} \, : \, \mathbb{E} X_t = 0 \hbox{ and } \mathbb{E}[X_t^2]< \infty, \, \forall\, …
2
votes
Distributions of distance between two random points in Hilbert space
Here is another variation of the fine solution suggested by Mike and made precise by Iosif Pinelis.
Let $Z$ be a polish (i.e., separable and complete) metric space with metric $d(\cdot,\cdot).$
Given …
2
votes
Vector version of concentration of Lipschitz functions on sphere (Levy's Lemma)
One can avoid the $n$-dependence. Let $H$ be a Hilbert space, endowed with the norm
$\|\cdot\|$.
Given $f:\mathbb{S}^{d-1}\to H$ which is $L$-Lipschitz, the goal is to prove a concentration inequalit …
4
votes
Accepted
Local probabilities for lattice random walk
For the one dimensional case, a quite nice bound is in Theorem 4.2 of [1]. See also [2]. The dependence on $\epsilon$ that you seek was first shown by Kesten[3].
The combinatorial approach was revive …
1
vote
Accepted
Bernoulli trials with small dependencies: asymptotics (central limit theorem, law of the ite...
For $0<\beta \le 1/2$, any limiting distribution of the rescaled process $S_n/n^\beta$ will be fully supported in $[-1,1]$, so it will not be normal.
The downward drift will imply (using Hoeffding's …