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Questions tagged [pr.probability]

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

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Monte Carlo method and possible applications to computer poker?

I want to do something about ”games of incomplete information“,like "Computer poker program".I know,Albert university(in canada) have do a lot of things to that field,they write a program called: "...
Xian_milk's user avatar
1 vote
3 answers
246 views

Extreme value theory

I have been asked to provide an "approximation at infinity" of an expression that at the end simplifies to $-\frac{b e^{-a t}-a e^{-b t}}{a-b}$, in a course about extreme value theory. In the course, ...
JOspina's user avatar
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2 votes
2 answers
254 views

Nice way to parametrize a bunch of non-independent discrete random variables

I'm looking for a "nice" way to parametrize the joint distribution of multiple, possibly correlated discrete random variables on {0,1}. Even for N=2, there doesn't seem to be an obvious way to do it. ...
David Shor's user avatar
20 votes
3 answers
1k views

The probability for a sequence to have small partial sums

The question Let $a_1,a_2,\dots,a_n$ be a sequence whose entries are +1 or -1. Let t be a parameter. My question is to give an estimate for the number of such sequences so that $|a_1+a_2+\dots ...
Gil Kalai's user avatar
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7 votes
2 answers
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Examples of Slowly Mixing Chains in Statistics

This should probably be community wiki, but I don't know how to set that myself. I'm looking for examples or Markov chains that are used in statistics or statistical physics, and which are known to ...
StatsWriter's user avatar
18 votes
1 answer
872 views

What's the probability that k + n^2 is squarefree, for fixed k?

While playing around with this question (when is the sum of two squares squarefree?), from some experimental computations (and bolstered by the fact that the density of squarefree positive integers is ...
Michael Lugo's user avatar
2 votes
1 answer
321 views

How to show that an infinite sequence is normal if and only if every block of equal length appears with equal frequency?

An infinite sequence is normal if all strings of equal length occur with equal asymptotic frequency. Formally, let $\Sigma$ be a finite alphabet of $b$ digits. Let $S$ be an infinite sequence and $\...
Zeyu's user avatar
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18 votes
2 answers
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Big Picture: What is the connection of Malliavin calculus with differential geometry?

I know that Paul Malliavin was heavily influenced by ideas from differential geometry while developing his calculus on Wiener space. But what are the concrete analogies between both areas of ...
vitp's user avatar
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19 votes
7 answers
3k views

A geometric interpretation of independence?

Consider the set of random variables with zero mean and finite second moment. This is a vector space, and $\langle X, Y \rangle = E[XY]$ is a valid inner product on it. Uncorrelated random variables ...
angela's user avatar
  • 415
4 votes
2 answers
2k views

Convergence of Gaussian measures

Let $X$ be a separable Banach space with its Borel $\sigma$-algebra $\mathcal F$. Let $x_n \to x$ in $X$. Fix a Gaussian covariance operator $K$, and let $\mathbb P_n$ and $\mathbb P$ be Gaussian ...
Tom LaGatta's user avatar
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3 votes
1 answer
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Finitarily Markovian Finite Factors of Bernoulli Schemes

By processes, I mean discrete, stationary stochastic processes, that is $(X,\mathcal{U},\mu,T)$ where $X$ is the set of doubly infinite sequences of some alphabet $A$, $\mathcal{U}$ is the $\sigma$-...
Stephen Shea's user avatar
6 votes
1 answer
3k views

Minimum Hamming Distance Distribution in a Random Subset of Binary Vectors+

Select $K$ random binary vectors $Y_i$ of length $m$ uniformly at random. Let the following collection of random variables be defined: $X_{i,j}=w(Y_i \oplus Y_j)$ where $w(\cdot)$ denotes the Hamming ...
kodlu's user avatar
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5 votes
3 answers
2k views

Binomial distribution parity

Let $X \text{~} \text{Binomial}(n, p)$. What is $\text{P}[X \mod 2 = 0]$? Is it of the form $1/2 + O(1/2^n)$?
Marc's user avatar
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4 votes
1 answer
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Generalized Cox Theorems, valuations on boolean sets, bayesian probabilities and posets

Bayesian probabilities are usually justified by the Cox theorems, that can be written this way: Under some technical assumptions (continuity, etc, etc...), given a set $P$ of objects $A, B, C, \ldots$...
1 vote
1 answer
783 views

Probability of n k-sided dice showing exactly m different faces

I found the following closed form solution for the abovementioned problem: $${1\over k^n}\cdot{k!\over (k-m)!}\cdot{\{{n\over m}\}}$$ with ${\{{n\over m}\}}$ being the Stirling Number of the second ...
vonjd's user avatar
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11 votes
2 answers
836 views

Quantum analogue of Wiener process

The Wiener process (say, on $\mathbb{R}$) can be thought of as a scaling limit of a classical, discrete random walk. On the other hand, one can define and study quantum random walks, when the ...
Marcin Kotowski's user avatar
6 votes
3 answers
13k views

Probability of one binomial variable being greater than another.

I need to calculate (or bound) the probability that one binomial variable is greater than other. Specifically, if $x \leftarrow B(n,p)$ and $y \leftarrow B(n,q)$, what is the probability that $y \...
user4120's user avatar
15 votes
3 answers
2k views

Disintegrations are measurable measures - when are they continuous?

This is a sequel to another question I have asked. The notion of disintegration is a refinement of conditional probability to spaces which have more structure than abstract probability spaces; ...
Tom LaGatta's user avatar
  • 8,512
11 votes
4 answers
3k views

When does a probability measure take all values in the unit interval?

Let $\mathbb{P}$ be a probability measure on some probability space $(\Omega,\mathcal{A})$. Are there conditions on the $\sigma$-algebra $\mathcal{A}$ such that for every real number $c\in [0,1]$ we ...
vitp's user avatar
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4 votes
2 answers
1k views

Can we extract information about how fast a function decay from its Laplace transform?

My question is whether we can extract information about how fast an integrable function converges to zero by looking at the asymptotics of its Laplace transform. More concrete case, let $f:\mathbb{R} ...
gondolier's user avatar
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3 votes
2 answers
324 views

How to fill a simplex with almost disjoint cuboids?

There is an algorithm that give us cuboids in $\mathbb{R}^3$, say $Q_1,Q_2,\ldots$, such that $\cup_{i=1}^{\infty} Q_i$ is the simplex with vertices $(0,0,0), (1,0,0) , (0,1,0), (0,0,1)$, and the $Q_i$...
Andrés's user avatar
  • 33
8 votes
3 answers
511 views

MicroArray, tesing if a sample is the same with high variance data.

I'll explain the problem but what I am looking for is a few suggested methods to approach this problem. You don't need to know what a microarray but if you are interested look here link text The info ...
Lisa's user avatar
  • 83
11 votes
2 answers
758 views

Notions of "independent" and "uncorrelated" for subsets of the natural numbers

In probability/statistics, there is a notion of two things being "independent", which would basically mean that any information we can get about one thing has no effect on our (probabilistic)...
Vipul Naik's user avatar
  • 7,320
2 votes
3 answers
2k views

Distribution of the sum of the $m$ smallest values in a sample of size $n$

Let $\mathbf X = [X_1, X_2, \ldots, X_n]^\mbox{T}$ be a vector random variable drawn from a known distribution with CDF $F(x)$. The CDF for the minimum value in $\mathbf X$ is clearly $P[\min_{i=1\...
ESultanik's user avatar
  • 183
6 votes
1 answer
836 views

Peakedness of multimodal distributions

In Probability theory, does there exist some measures of peaked-ness for multi-modal distributions. I guess kurtosis as such would not be a good measure of peaked-ness for multimodal distributions. ...
CSK Varma's user avatar
18 votes
4 answers
3k views

Markov chain on groups

Let $G$ be a permutation group on the finite set $\Omega$. Consider the Markov chain where you start with an element $\alpha \in \Omega$ chosen from some arbitrary starting probability distribution. ...
Gjergji Zaimi's user avatar
2 votes
2 answers
2k views

Hitting times for an N-dimensional random walk on a lattice with (strictly positive) random integer steps

Please consider a random walk on a finite N-dimensional lattice with vectors $(x_1, ..., x_N)$. We define the origin to be $(0, ..., 0)$ and the target to be at the point in the lattice furthest away ...
Rob Grey's user avatar
  • 599
9 votes
1 answer
2k views

Kullback-Leibler divergence of scaled non-central Student's T distribution

What is the Kullback-Leibler divergence of two Student's T distributions that have been shifted and scaled? That is, $\textrm{D}_{\textrm{KL}}(k_aA + t_a; k_bB + t_b)$ where $A$ and $B$ are Student's ...
Neil's user avatar
  • 598
6 votes
2 answers
3k views

Dense inclusions of Banach spaces and their duals

This seems like a really simple question, but I'm struggling with it. Let $X$ be a separable Banach space, $H$ be a separable Hilbert space, and suppose $i : H \hookrightarrow X$ is a dense, ...
Tom LaGatta's user avatar
  • 8,512
28 votes
6 answers
2k views

Random Alternating Permutations

An alternating permutation of {1, ..., n} is one were π(1) > π(2) < π(3) > π(4) < ... For example: (24153) is an alternating permutation of length 5. If $E_n$ is the number of alternating ...
john mangual's user avatar
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-1 votes
1 answer
545 views

probability mass function fitting [closed]

I have a probability mass function of some experimental data who's log looks like the following: (please ignore the fact that it is not normalized) ![alt text][1] [image shack image removed] (...
liza's user avatar
  • 307
4 votes
6 answers
1k views

Are there nonequivalent randomnesses?

There are nonequivalent geometries, nonequivalent groups finite and infinite, nonequivalent logics ( fregean and nofregean http://www.formalontology.it/suszkor.htm), even nonequivalent logicians;-) ...
kakaz's user avatar
  • 1,626
1 vote
2 answers
573 views

Exploding Levy processes

Hi, probably this is a fairly newbie question, but is it possible that the a generic Levy process explodes (i.e. tends to infinity for finite time t with positive probability)? If yes, could you ...
Grzenio's user avatar
  • 667
9 votes
0 answers
2k views

Has the Lie group preserving a probability distribution been used in Bayesian statistics?

For a (possibly signed) nondegenerate probability measure $\pi$ on $\{1,\dots,n\}$ define $$\langle \pi \rangle := \{R \in \operatorname{STO}(n): \pi R = \pi \}.$$ Here $\operatorname{STO}(n)$ denotes ...
Steve Huntsman's user avatar
14 votes
6 answers
2k views

Density of numbers having large prime divisors (formalizing heuristic probability argument)

I want to prove that the set of natural numbers n having a prime divisor greater than $\sqrt{n}$ is positive. I have a heuristic argument that this density should be $\log 2$, which is approximately ...
Vipul Naik's user avatar
  • 7,320
3 votes
1 answer
320 views

Joint Law with 2 marginals and marginal of the spread

I have a question for you and thank you in advance for your answers and ideas. Let us suppose that we have the marginal distributions of two r.v X and Y, and also the law of X-Y (or any linear ...
Averroes's user avatar
  • 375
3 votes
4 answers
2k views

statistical approach to multinomial distribution

Suppose a dice with $q$ faces is rolled $N$ times, where $N$ is very big. We define a multinomial variable $X=(X_1,\ldots,X_q)$ which counts how many times any face is occurred ($X_i$ is the number ...
Stefano's user avatar
  • 31
6 votes
2 answers
360 views

Asymptotics of symmetry types of tensors

Introduction Let's fix $m\in \mathbb N$. For each n, the unitary group $\mathbf U(m)$ is represented in the space of tensors of rank $n$ over $\mathbb C^m$ $$V_{n,m}=\bigotimes_{k=1}^n \mathbb C^m$$ ...
Gjergji Zaimi's user avatar
7 votes
4 answers
946 views

On operator ranges in Hilbert & Banach spaces

Lemma 1 from Anderson & Trapp's Shorted Operators, II isLet $A$ and $B$ be bounded operators on the Hilbert space $\mathcal H$. The following statements are equivalent: (1) ran($A$) $\subset$ ...
Tom LaGatta's user avatar
  • 8,512
2 votes
0 answers
1k views

Problem with Pearson correlation coefficient. [closed]

I have two random variables X and Y. X follows a power law distribution. I know its generating function G(x). I also know the Pearson correlation coefficient of X and Y. How do I find the generating ...
Peter's user avatar
  • 31
10 votes
1 answer
567 views

Is this a well-known probabilistic model?

While I was thinking about the Erdős discrepancy problem, the following random walk model arose rather naturally. You fix a positive integer k, and you take a random step of 1 or -1 at each stage,...
gowers's user avatar
  • 29k
5 votes
0 answers
537 views

Conditional probabilities in Banach spaces

This is the infinite-dimensional sequel to my question, Conditional probabilities are measurable functions - when are they continuous?. Let $\Omega = \Omega_1 \times \Omega_2$ be a probability space ...
Tom LaGatta's user avatar
  • 8,512
5 votes
2 answers
1k views

Is there a way to analytically compute the recurrence time of a finite Markov process?

Let $X_t$ be an ergodic (time-homogeneous) Markov process (in discrete or continuous time) on a finite state space $\{1,\dots,n\}$. Let $T(X_0)$ be the stopping time given by the infimum of times such ...
Steve Huntsman's user avatar
6 votes
3 answers
423 views

Infinite electrical networks and possible connections with LERW

I've been exposed to various problems involving infinite circuits but never seen an extensive treatment on the subject. The main problem I am referring to is Given a lattice L, we turn it into a ...
Gjergji Zaimi's user avatar
3 votes
1 answer
635 views

Non-existence of integral with respect to Poisson Random Measure

Let $\xi$ be a Poisson Random Measure of intensity $\mu$ (informally $\mathbb E\xi = \mu$). (For $f \ge 0$, say) when does $\xi f = \infty?$ Kallenberg (Foundations of Modern Probabilility) claims ...
Tom Ellis's user avatar
  • 2,895
1 vote
1 answer
3k views

Equality in the union bound.

Lemma: Let $A_1,\ldots,A_n$ are events $n\in\mathbb{N}$ then $$ \sum_{i=1}^n \mathbb{P}(A_i) = \mathbb{P}(\cup_{i=1}^n A_i) $$ if and only if $A_1,\ldots,A_n$ are mutually exclusive. Both ways are ...
alext87's user avatar
  • 3,217
4 votes
3 answers
2k views

Correspondence between Viterbi algorithm and Smith-Waterman

Viterbi is an algorithm for finding the maximum likelihood assignment to the hidden variables of an HMM, given the observed variables (we know the transition and emission probabilities of the HMM). ...
Jonathan's user avatar
  • 233
17 votes
5 answers
3k views

Conditional probabilities are measurable functions - when are they continuous?

Let $\Omega$ be a Banach space; for the sake of this post, we will take $\Omega = {\mathbb R}^2$, but I am more interested in the infinite dimensional setting. Take $\mathcal F$ to be the Borel $\...
Tom LaGatta's user avatar
  • 8,512
5 votes
3 answers
426 views

How many trial picks expectedly sufficient to cover a sample space?

Consider a sequence of independent events where an $r$ element subset of an $n$ element set is picked uniformly randomly (ie. any of the $\begin{pmatrix}n\newline r\end{pmatrix}$ possibilities being ...
amaanush's user avatar
  • 119
3 votes
4 answers
22k views

Football Squares

Dear Colleagues, This is a math question for people who know the rules of (American) football. Every year my barber runs a “football squares” game. He finds 100 customers, each put in 20 dollars, ...
Claude Schochet's user avatar