Skip to main content
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
Results tagged with
Search options not deleted user 29697

Theory and applications of probability and stochastic processes: e.g. central limit theorems, large deviations, stochastic differential equations, models from statistical mechanics, queuing theory.

88 votes

Why do roots of polynomials tend to have absolute value close to 1?

I think the following geometric argument is interesting and maybe sufficient to answer "why" at an intuitive level (?). When we take the powers of $x$ in the complex plane, the absolute value scales g …
usul's user avatar
  • 4,529
5 votes

concentration inequality for entropy from sample

Here's a step that seems nice enough to point out. It still leaves a parameter to pick, and I'm not sure it's ever better than applying Bernstein, but it does something different. We can get a probab …
usul's user avatar
  • 4,529
5 votes
1 answer
318 views

Bounding the max-loaded bin using${m \choose k} \|A\|_k^k$

Throw $m$ balls into $n$ bins independently, each ball selecting a bin from the distribution $A \in \Delta_n$. This question is about lower-bounding the max-loaded bin. Background. In this MO answer I …
usul's user avatar
  • 4,529
4 votes
3 answers
337 views

Do subgaussian variables obey the slightly-stronger-than-Chernoff tail bound?

If $X \sim Normal(0,1)$, then we have the tail bound: $$ (*) \qquad\Pr[X > t] \leq \mathcal{O}\left(\frac{e^{-t^2/2}}{t}\right) .$$ Now for general variables $X$, a nice condition is that $X$ be su …
usul's user avatar
  • 4,529
4 votes

Deciding when to stop searching for a new type of shell on a beach?

The Good-Turing estimator addresses a very similar problem. The model is that there is an unknown number of types $n$ and a probability distribution $p \in \Delta_n$. Each time you pick up a new she …
usul's user avatar
  • 4,529
4 votes
1 answer
472 views

Concentration inequalities in $\ell_{\infty}$ for sums of iid random ("nice") functions?

I'm looking for "tail-bound-like" inequalities that look like this (I state a specific setting but more general settings are interesting): Let $D$ be a distribution on a set of "nice" functions $g …
usul's user avatar
  • 4,529
4 votes

The relative error of approximating a binomial

Don't forget that far out in the left tail, the Binomial CDF is multiplicatively approximated by the PMF, because terms grow geometrically. Example. For $t \leq \frac{np}{2}$, we claim $\Pr[X = t] \le …
usul's user avatar
  • 4,529
4 votes
Accepted

Do these $L^p$ type statistics characterize distributions?

No, it looks like many different sufficiently symmetric distributions with enough concentration at $0$ will have $\arg\min_c E[|X-c|^p] = 0$ for all $p > 0$. Concrete family of examples: if $$ X = \be …
usul's user avatar
  • 4,529
4 votes

Proofs of main probability results from other fields

Maybe this is a stretch, but laws of large numbers, and more precise concentration of measure bounds, can be proven by the "isoperimetric" approach which can be called geometric and was pioneered by T …
4 votes

The distribution of the number of chord intersections

For the expectation, linearity of expectation should help a lot. There are ${n\choose 2}$ pairs of chords, and if each chord is drawn i.i.d. then each pair has some probability of intersection of $p$, …
usul's user avatar
  • 4,529
3 votes
Accepted

Does there exist a Penalized Conditional Expectation?

This is a bit different and doesn't address the question, but hopefully close enough to be useful: we know some things about $\mathbb{E} L(Z,Y)$ for other loss functions $L$. If and only if $L$ is a …
usul's user avatar
  • 4,529
3 votes

Example of a (strictly) proper scoring rule on a general measurable space?

Turns out that Gneiting and Raftery give an example in Section 4.2 of the continuous ranked probability score (CRPS), which is strictly proper for $\mathcal{P}$ equal to the Borel probability measures …
usul's user avatar
  • 4,529
3 votes

Can we do better than Azuma-Hoeffding when the variance is small?

Adding to Iosif Pinelis' answer, there are two points here. First, as he says, the fact that we have a martingale rather than i.i.d. variables doesn't change much as proofs generally extend. So, secon …
usul's user avatar
  • 4,529
3 votes
Accepted

Bounds on the mills ratio

Here's a sketch and a link for how I prove it. Let $$ f(x) = - \left( \frac{1}{x} - \frac{1}{x^3} + \frac{3}{x^5}\right) \phi(x) .$$ Now show (lemma): $\frac{df}{dx} = \left(1 + \frac{15}{x^6}\righ …
usul's user avatar
  • 4,529
3 votes

Finite-sample deviation bound of empirical distribution from true distribution

A self-contained proof. Step 1: $\mathbb{E} \|\hat{P}_n - P\|_2^2 \leq \frac{1}{n}$. Step 2: McDiarmid's inequality. Let $X_i$ be the number of samples of $i \in \{1,\dots,k\}$. Then $X_i \sim \te …
usul's user avatar
  • 4,529

15 30 50 per page