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4 votes
0 answers
98 views

Weighted distribution of irrational rotation

Let $\theta\in [0,1]\setminus\mathbb{Q}$. Let $\alpha_0=\theta$ and $\alpha_1=1$. Let $0<p_0<1$ and $p_1=1-p_0$. For a finite word $I=(i_1, i_2, \dots, i_n)\in \{0,1\}^n$, denote by $I'=(i_1, ...
user119197's user avatar
4 votes
1 answer
277 views

Shannon entropy of $p(x)(1-p(x))$ is no less than entropy of $p(x)$

If $p(x)$ is a discrete probabilistic density function, one could construct another discrete probabilistic density function proportional to $p(x)[1-p(x)]$ with a corresponding partition function to ...
sunxd's user avatar
  • 191
8 votes
3 answers
255 views

Random reflections unexpectedly produce banded distributions

Start with $p_1$ a random point on the origin-centered unit circle $C$. At step $i$, select a random point $q_i$ on $C$, and a random mirror line $M_i$ through $q_i$, and reflect $p_i$ in $M_i$ to ...
Joseph O'Rourke's user avatar
2 votes
1 answer
119 views

time delay ergodic theorem

given dynamic system $(X, \mathcal{B}, F, \mu), \mu \circ F^{-1}=\mu, F $ is mixing, $ A \in \mathcal{B}, s.t. \mu(A) >0 $. consider dynamic system $(X\times X, \mathcal{B}\otimes \mathcal{B}, ...
jason's user avatar
  • 553
3 votes
0 answers
123 views

Maximal ergodic theorem on some dyadic intervals

What we refer to maximal ergodic theorem in this thread is the following: let $\left(\Omega,\mathcal F,\mu\right)$ be a probability space and let $T\colon\Omega\to \Omega$ be a measurable and measure ...
Davide Giraudo's user avatar
4 votes
2 answers
2k views

On Mathematical Foundations of Football

Football (soccer) is arguably one of the most unpredictable sports. Countless variables play a role in determining the outcome of a certain football match. Due to the high complexity of the entire set ...
Morteza Azad's user avatar
5 votes
0 answers
143 views

Smoothing properties of convolutions of $P^1(\mathbb{R})$ by $SL(2,\mathbb{R})$

Consider the action of $SL_2(\mathbb R)$ on real projective space $P^1(\mathbb R)$; given $A \in SL_2(\mathbb R)$ and $\alpha \in P^1(\mathbb R)$ we write $A . \alpha \in P^1(\mathbb R)$ for this ...
A Blumenthal's user avatar
1 vote
0 answers
79 views

Dynamics for sets related to Brownian motion: zero set, fast points

For sets like the Cantor set, we have preserving maps (eg. the shift-maps and conjugates to it) that allows us to study dynamical quantities such as invariant measure and entropy. I am wondering if we ...
Thomas Kojar's user avatar
  • 5,474
3 votes
2 answers
194 views

A Really Simple Stochastic Dynamic Billiard

Consider the following stochastic dynamical system. Fix $a > 0$, $b > 0$, $c>0$ and $v > 0$, and let $\mathbf{r}(t)=(x(t),y(t),z(t))$ be the position at time $t$ of a point which moves ...
Maurizio Barbato's user avatar
3 votes
1 answer
127 views

A Simple Stochastic Dynamic Billiard

Consider the following stochastic dynamical system. Fix $a > 0$, $b > 0$, and $v > 0$, and let $\mathbf{r}(t)=(x(t),y(t))$ be the position at time $t$ of a point which moves in the ...
Maurizio Barbato's user avatar
10 votes
2 answers
678 views

Irrational rotation - recurrence times

I consider the irrational rotation $T_\alpha(x) = x + \alpha \text{ mod } 1$ for given irrational $\alpha \in [0,1]$. For a given open interval $A \subset [0,1]$ with length $|A|>0$, I consider the ...
kamui's user avatar
  • 103
1 vote
1 answer
208 views

Absolute continuity of harmonic measure for a random walk and its reflection

Let $G$ be a hyperbolic group, and $\mu$ a (nonsymmetric) probability measure on $G$ whose support generates $G$ as a semigroup. Let $\nu$ be the associated harmonic ($\mu$ stationary) on $\partial G$....
Yellow Pig's user avatar
  • 2,964
3 votes
3 answers
394 views

When is the minimal Martin boundary closed?

Let $\Gamma$ be a finitely generated group and $\mu$ a symmetric measure of finite support on $\Gamma$. Let $\partial_{M}\Gamma$ be the Martin boundary of $(\Gamma,\mu)$ and let $\partial^{min}_{M}\...
Yellow Pig's user avatar
  • 2,964
1 vote
0 answers
336 views

Existence of solution for Poisson equation in Markov chain

Consider $X_n\in \mathcal{X}$ a controlled Markov chain taking value in a compact set $\mathcal{X}$ with action $a\in \mathcal{A}$, where the action set $|\mathcal{A}|$ is finite. (In particular, we ...
Sung-En Chiu's user avatar
12 votes
2 answers
3k views

Is it fine to inquire about a paper that's been under review for around 9 months?

I have submitted a paper on applied probability in one of SIAM journals. The paper is under review for 9 months. I asked the editor 1 month ago about it, I was told that one review report has come and ...
1 vote
1 answer
202 views

Return time estimates in countable state Markov chains

Consider a countable-state Markov chain; for the sake of concreteness identify the set of states with the set of nonnegative integers {0, 1, 2, ... }. Suppose the transition probabilities $P_{ij} = \...
Vaughn Climenhaga's user avatar
4 votes
0 answers
56 views

Is there an equivalent line time-invariant system for a linear time-varying system with specific properties? [closed]

Given a discrete-time linear time-varying system (LTV) $$x(k+1) = A(k) x(k) + B(k) u(k)$$ where $A(k)$ and $B(k)$ are generated by a stationary random process. Is there an equivalent linear time-...
Ed Tate's user avatar
  • 141
10 votes
1 answer
494 views

Ping-pong progress through a quincunx

A quincunx or Galton board consists of staggered pegs from which ping-pong balls bounce and eventually display a binomial / normal distribution in catch-bins. I am wondering if the downward progress ...
Joseph O'Rourke's user avatar
4 votes
1 answer
173 views

Expectation and Dependence

Probably a very simple question, I think I'm looking for a general statement that says 'if one decreases the independence between two processes then the expected value of the maximum of these two ...
Tom Kempton's user avatar
4 votes
1 answer
222 views

Is there a version of the Return Times Theorem for Dunford-Schwartz operators?

Bourgain's "Return Times Theorem" establishes that if $(\Omega_{j},\mathcal{F}_{j},\mathbb{P}_{j},T_{j})$ ($j=1,2$) are measure-preserving Dynamical systems (i.e. $(\Omega_{j},\mathcal{F}_{j},\mathbb{...
David's user avatar
  • 486
2 votes
1 answer
200 views

Measurable isomorphism between two non-totally ergodic systems

Suppose $(X,\mathcal A,\mu,T)$ is a finite measure-preserving system. Then we define a new measure system $(X^{(K)},\mathcal A^{(K)},\mu^{(K)},T^{(K)})$ defined by $X^{(K)}=X\times \{1,2,...,K\}$ for ...
Landon Carter's user avatar
2 votes
0 answers
157 views

Gaussian Integrals and Pseudo-Anosov Maps

The hep-th section of arXiv if often filled with beautiful semi-rigorous computations on Mathematics. However sometimes it is very difficult to understand what is being stated. Here I take from: ...
john mangual's user avatar
  • 22.8k
2 votes
0 answers
491 views

Is there a Bayesian theory of deterministic signal? Prequel and motivation for my previous question

This is a prequel to my question: What's the probability distribution of a deterministic signal or how to marginalize dynamical systems? (functional integrals in probability theory) Clearly my ...
Fabrice Pautot's user avatar
3 votes
0 answers
157 views

Question about martin boundaries of random walks induced on transient subgroups

Suppose $\Gamma$ is a discrete, finitely generated, non-amenable group, and consider a random walk given by a measure $\mu$. Assume the measure is symmetric, finitely generated, and the support of $\...
Yellow Pig's user avatar
  • 2,964
6 votes
2 answers
3k views

What's the probability distribution of a deterministic signal or how to marginalize dynamical systems? (functional integrals in probability theory)

Because I still have no idea how it is possible for me to write down seemingly important equations ... that don't make any sense (at least for me) and because I haven't got any helpful comment so far, ...
Fabrice Pautot's user avatar
2 votes
0 answers
299 views

A weighted ergodic average

According to my simulations, it looks like the number of times that the $N$ first iterates $u_0$, $\ldots$, $u_{N-1}$ of the sequence $(u_n)$ defined here meets an interval $I$ is close to $N|I|$ ...
Stéphane Laurent's user avatar
5 votes
0 answers
81 views

What statistical data/quantities are known about the time spent by a generic orbit of an ergodic system in a fixed set?

By the ergodic theorem, we know that for almost every point, the average time spent by an orbit in a set is equal to the relative measure of that set. What other information about that time can we ...
user avatar
7 votes
2 answers
321 views

Random suborbits of a rotation

Let $u_n = x + n\alpha \pmod 1$ with $\alpha$ irrational. We know that $(u_n)_{n \geq 0}$ is dense in $\mathbb{R}/\mathbb{Z}$ (equivalently $(u_n)_{n \geq 0}$ visits every open interval infinitely ...
Stéphane Laurent's user avatar
2 votes
2 answers
492 views

Can I use Birkhoff's Ergodic Theorem for Vector Valued Process?

I have a stationary process $\{u_n\}$ and I have a function $f:\mathbb{R}^L\to \mathbb{R}^+$. I want to evaluate the following limit $$\lim_{n\to \infty}\frac{1}{n}\sum_{k=1}^n g(f(\mathbf{u}_{k}))$$ ...
Samrat Mukhopadhyay's user avatar
13 votes
7 answers
2k views

Finite-space dynamical systems

This question is quite open-ended, but I will formulate several sub-questions that I'll try to make precise. It is about finite-state dynamical system: start with a finite set $X$, with say $n$ ...
Benoît Kloeckner's user avatar
15 votes
1 answer
1k views

In how many steps a random walk visits all the elements of a finite group, with a probability 1/2?

This question is a variation of the return to the origin problem. Let $G$ be the finite group $\mathbb{Z}/n \times \mathbb{Z}/n$ and let the random transformation $T: G \to G$ such that $T(a,b) = (...
Sebastien Palcoux's user avatar
3 votes
0 answers
209 views

On the decay of correlations of an ergodic sequence over the set $X_{0}=0$

The following question arose while I was trying to explore possible further extensions of a CLT by Liverani which I mentioned here already (see this link, I can tell you more details upon request). It ...
David's user avatar
  • 486
5 votes
0 answers
127 views

First return time in an interval for N particles rotating on the circle at constant random speeds

Here is my problem: draw N velocities $v_1,v_2,\dots,v_n$ in $[-\pi,\pi]^N$ from some measure (Haar measure of uniform independent for simplicity) and make $N$ particles rotate around the circle with ...
Olivier Marchal's user avatar
18 votes
0 answers
667 views

The lonely molecule

Suppose $n$ air molecules (infinitesimal points) are bouncing around in a unit $d$-dimensional cube, with perfectly elastic wall collisions. Let $k=n^{\frac{1}{d}}$. For example, in 3D, $d=3$, with $n=...
Joseph O'Rourke's user avatar
18 votes
3 answers
1k views

Not-lonely runners

The lonely runner conjecture has several formulations. They all involve a number $n$ runners running on a circular track, each with a different speeds, and the conjecture is that each runner is ...
Joseph O'Rourke's user avatar
21 votes
3 answers
1k views

Central Limit Theorem(s) for irrational rotation

Let $\alpha$ be irrational and $T: S^1 \rightarrow S^1$ be the rotation by $\alpha$. I'm interested in what type of Central Limit Theorem (if any) can hold for sums $Y_n = \frac{1}{\sqrt{n}}\sum_{k=1}^...
Marcin Kotowski's user avatar
5 votes
1 answer
348 views

"strongly mixing" action on dimers?

In Local Statistics of Lattice Dimers we study a nice familiar object, domino tilings in the plane extending out to infinity. His paper is going to discuss the frequency of various "motifs" in ...
john mangual's user avatar
  • 22.8k
7 votes
2 answers
335 views

Wait time to grid network disconnection with failing edges

Let $G_n$ be an $n \times n$ planar toroidal grid graph, with each node connected to its four neighbors, with the top row connected to the bottom, and the right column connected to the left. Suppose ...
Joseph O'Rourke's user avatar
1 vote
2 answers
415 views

$\{\phi:\int \phi d\mu=0\}$ for a fixed shift invariant $\mu$

Given a shift invariant probability measure $\mu$ on a mixing subshift of finite type. What are the Lipschitz functions with zero integral with respect to the measure $\mu?$ Clearly any $\phi\in\{-u+...
user39115's user avatar
  • 1,805
15 votes
2 answers
571 views

Spearing rolling hula hoops

Or: Stabbing rolling disks. Imagine there are $n$ unit-diameter disks rolling between $x=0$ and $x=d$, reflecting off either end. The disk centers start at a random location within $[\frac{1}{2}, d-\...
Joseph O'Rourke's user avatar
2 votes
0 answers
81 views

Link between presence of attracting random fixed points and synchronisation - is this an open question?

This is a question in the theory of random dynamical systems. Let $(X,d)$ be a compact metric space, let $(I,\mathcal{I},\nu)$ be a probability space, and let $(f_\alpha)_{\alpha \in I}$ be an $I$-...
Julian Newman's user avatar
11 votes
2 answers
928 views

Random circle rotations

Weyl's equidistribution theorem states that the orbit of a point on the circle under rotation by $\alpha$ becomes asymptotically equidistributed with respect to Lebesgue (Haar) measure whenever $\...
Vaughn Climenhaga's user avatar
7 votes
1 answer
319 views

Why aren't operator semigroups studied from a dynamical perspective?

Often times one talks about iterating a continuous map to get discrete topological dynamics, or having a 1-parameter family of continuous maps to get continuous topological dynamics. When studying ...
Jeff's user avatar
  • 277
5 votes
0 answers
221 views

Quasicompactness of transfer operators associated to IID matrix products

Let $P^1$ denote one-dimensional real projective space, and for each $A \in GL(2,\mathbb{R})$ let $\overline{A}$ denote the homeomorphism of $P^1$ induced by $A$. I am currently reading a paper which ...
Ian Morris's user avatar
  • 6,206
3 votes
1 answer
3k views

Good books on stochastic partial differential equations?

I have a system of 2 PDEs, one with a probabilistic right side, and kind of stuck on what to read about those things.. Any good books around? Both analytical (if any) and numerical methods are welcome....
mt_christo's user avatar
2 votes
1 answer
1k views

Derivative of a random process

Consider $w(t)$ as Guassian random process, with $w(t)$ being $\mathcal{N}(\mu,\sigma)$ and i.i.d for all t. I consider applying a (stochastic)derivative operation to the random process. What is the ...
Neeks's user avatar
  • 151
9 votes
2 answers
586 views

Fixed objects of the M endofunctor on category Meas

Consider the category $\operatorname{Meas}$ of measurable spaces: its objects are sets equipped with $\sigma$-algebras, and its morphisms are measurable functions between spaces. As Gerald Edgar &...
Tom LaGatta's user avatar
  • 8,512
5 votes
1 answer
140 views

Do distinct idempotent measures on finite binary systems have distinct supports?

Suppose that $(S,*)$ is a finite set equipped with a binary operation. Extend the binary operation to the vector space $V$ with basis $S$. The set of probability measures on $S$, viewed as a compact ...
Justin Moore's user avatar
  • 3,547
2 votes
1 answer
348 views

random matrix products reference

For a long time the standard (though not the easiest to find) reference on random matrix products was Bougerol and Lacrois: Bougerol, Philippe, and Jean Lacroix. Products of random matrices with ...
Igor Rivin's user avatar
  • 96.4k
7 votes
0 answers
299 views

Generalized Skorokhod spaces

Skorokhod spaces of càdlàg functions are an extremely useful setting to describe stochastic processes. I'd like to understand the Skorokhod topology from a pure topological point of view, without ...
Tom LaGatta's user avatar
  • 8,512