A stochastic process satisfying the Markov property: the distribution of the future states given the value of the current state does not depend on the past states. Use this tag for general state space processes (both discrete and continuous times); use (markov-chains) for countable state space ...

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Why does markov chains power method converge at the rate of |λ_2/λ_1 |

I'm doing some researches on Markov Chains, and every time I meet this statement, that The rate of convergence of the power method is given by |λ_2/λ_1 |^k→0, when k→inf. And where λ_1 and λ_2 are ...
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Markovian Coefficients Unclear Definitiondtdt

I have come across the following unclear definition: Consider $dS(t) = S(t)[\mu(t)dt + \sigma(t) dW(t)]$ "Assume that the coefficient $\sigma$ is Markovian. That is, (with abuse of notation) ...
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14 views

Analysis of Steady State Probability for Markov Process

I have a balance equation, representing a Markov Chain, which yields $$ (K - z) \pi(Z_c = z) = (\lambda_c + (z+1)x) \pi(Z_c = z+1) $$ where K is the maximum state of the server. The term $\lambda_c$ ...
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17 views

Markov process which is not martingale

I have seen the examples of a discrete time martingale that is not a Markov Process. Can you construct me an example of discrete time Markov Process that is not a martingale?
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15 views

When are the marginals of an extremal invariant measure also extremal invariant?

Let's suppose that $X$ is a compact metric space, and thus as is $X \times X$. If given a Markov process on $X \times X$ with marginals that are Markov processes on $X$, then we know that the ...
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8 views

Hidden Markov Model to Markov Model

Can every HMM be converted into some $nth$ order Markov model? My thoughts are that you could just multiply the emission probabilities in each state by the probability of state transitions. For ...
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14 views

Computing the PMF for N(t) in a renewal process

I'm in a stochastic processes course, and we just started on renewal theory. Unfortunately, we skipped the section on queuing theory, and nearly example in my textbook for renewal processes uses ...
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$X_n, n> 0$ is a Markov Chain, how to interpret $Z_n = (X_n,X_{n+1}), n > 0$?

Am a newbie to Markov Chain. So, this might be incredibly naive/stupid question. If $X_n, \, n > 0$ is MC, am having difficulty imagining/interpreting process $Z_n = (X_n,X_{n+1}), n > 0$. I ...
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27 views

Continuous-time Markov Question

I have a question about a continuous-time Markov process on the discrete space. I am given the generator and asked for find the expected time the Markov process needs to get back to state 3, given ...
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24 views

Showing the square of a Markov process is or isn't Markov

Hi I am trying to show that if $X_n$ is a markov process, whether or not $X_n^2$ is a markov process. $X_n$ is a markov process if $P\{X_k = a_k|X_{k-1} = a_{k-1}, X_{k-2} = a_{k-2}, ..., X_k = a_1 ...
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Find the generator of Markov Process

Homework question: Consider the Markov process $X_t=B_t-t^2+t$ where $B_t$ is the Brownian motion. Find the generator $Q$ of this process. I am completely confused how to find the generator for ...
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Steady state of a $4 \times 4$ transition matrix

Normally I just take $q(M_{m\times n} - I_{m\times n})$ to workout the steady state, but here I have: $$\left(\begin{array}{rrrr} 0 & 0 & .8 & .2 \\ .4 & .6 & 0 & 0 \\ .2 ...
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17 views

Limiting probability of Markov chain(Terminology)

If I am asked to find the limiting probability of a Markov chain, what does this pertain to? $\lim \limits_{n \to \infty} P^n$? Where $P$ is the stepping matrix and $n$ is the number of steps. "What ...
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22 views

Error in thinking: Poisson Process is a Markov Process

I am a bit confused on proving the Markov property for Poisson processes. That is, we want to prove, if $X = (X_t: t \in \mathbb{R})$ is a Poisson process with rate $\lambda$: $P(X_{t_n} = a_n | ...
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26 views

How's the damping factor in Google PageRank algorithm calculated

I'm doing some researches about Google's PageRank algorithm for my thesis, I've found that the damping factor x (for example), where x is in : P` = x.P + (1-x)Q where P is the original ...
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31 views

Stationary distribution of a “birth-death model” that does not have Markov property

A typical birth-death process is defined such as the probability of going from any state $j$ to any state $i$ is given by: $$ p_{ij}= \begin{cases} b_i & \text {if $j = i+1$} \\ ...
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25 views

showing a condition implies convergence to invariant distribution

For an arbitrary Markov chain, I'm trying to show that $\lVert{ P_{\mu}\circ \theta_n^{-1} - \nu \rVert}\to 0$ iff $\sum_j \lvert{ P_{ij}^n - \nu(j)\rvert}\to 0$, where $\theta_n^{-1}$ is a shift ...
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20 views

inequality for finite state markov chains

Let $X$ be a discrete-time Markov process in $S$ with invariant distribution $\nu$. Show that for any measurable set $B\subset S$ such that $$P_{\nu}\{X_n \in B\, \textrm{i.o.} \}\geq \nu B.$$ I'm ...
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53 views

continuous time Markov chain, something the book does not explain

I have a problem with something in my book, under the chapter of continuous time Markov chains. I will post a link to what the book does. They do something which they seem to take for granted, but I ...
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radius of markov chain

For an irreducible markov chain one can show, that $\limsup \sqrt[n]{p_{ij}^{(n)}}$ is independent of the choice of the states $i$ and $j$ where $p_{ij}^{(n)}$ is the probability to get from $x$ to ...
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38 views

Representation of Markov process adapted to given Filtration

Let $X$ be continuous Markov process adapted to a filtration generated by Brownian motion $B$. Does there exist a function $f$ such that $X_t = f(t,B_t)$? My guess is that it should have such ...
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35 views

Ornstein-Uhlenbeck processs: Markov, but not martingale?

I'm puzzled about properties of the Ornstein-Uhlenbeck process, given by the Itō integral $$ X_t = x e^{-\lambda t} + \sigma \int_0^t e^{-\lambda(t-s)} d W_s \,. $$ I compute that $\{X_t\}$ is not ...
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31 views

Infinitesimal generator of Markov jump process and delta measure

How can I prove that the following integral is null? \begin{equation} \int_{\mathbf{R}^{d}} \gamma\left(z\right) \delta_{z}\left(y\right), \qquad \gamma>0 \end{equation} I want to use this ...
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47 views

Markov chain with infinite number of transient and positive recurrent states?

Is it possible to have a markov chain with an infinite number of transient states, and an infinite number of positive recurrent states? Thank you!
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222 views

Prove markov chain is null recurrent

Two fair coins are tossed repeatedly. Let Xn denote (Total Number of Heads from Coin 1)-(Total Number of Heads from Coin 2) after n tosses. Thus the state space is {0, ±1, ±2, .... }. Show that the ...
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18 views

Three-State Markov Process with Differential Equations

This question is from a take home quiz and I could really use the help. Thanks in advance
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2answers
62 views

Mean recurrence time and stationary distribution of a Markov chain?

In a Markov chain is there a theorem relating the existence of the stationary distribution and the mean recurrence time? E.g. impossible for stationary distribution to exist therefore mean recurrence ...
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62 views

proving null recurrence of random walk (Markov chain)

How would I prove that the zero state of a random walk with a positive probability of staying in the same state is null recurrent. (sorry if this isn't a random walk and just a Markov chain.) eg. ...
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61 views

What is the value of this game?

We have 3 black and 2 red balls in an urn. If we pick a black ball, we lose 1 USD. If we pick a red ball we win 1 USD. We can chose to start the game or not. If we start the game we can stop after ...
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26 views

Show $P(S_{2n}=x|S_0=x) \ge \frac{1}{N}$

Let $X_n$ be an aperiodic, discrete-time Markov chain so $S=\{1,...,N\}$ whose transition probability is symmetric. How can I show that for all $x \in S$ and all integers $n$, $P(S_{2n}=x|S_0=x) \ge ...
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22 views

Maximal principle for elliptic or linear integro-differential operator

Consider $L$ the operator forming as $$ Lg= -g^{'}(x)+(g(x+1)-g(x)) $$. $h$ on $[0,\infty)$ satisfies the following integro-differential equation $$ Lh \geq 0 $$ with boundary condition: $$ ...
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20 views

Transition rate matrix from transition probability matrix

If I have a $2 \times 2$ continuous time Markov chain transition probability matrix (generated from a financial time series data), is it possible to get the transition rate matrix from this and if ...
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28 views

Continuous time Markov chains, how would this definition be expanded from time-homogeneous to time-inhomogeneous.

Below I have a picture of how we can view a continuous time Markov chain that is time-homogeneous. Now, I am wondering what happens when we have a inhomogeneous continuous Markov chain. I have ...
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35 views

Markov processes and semimartingales

Semimartingales and Markov processes are two fundamental families in probability theory. There are many specific processes that belongs to the intersection of those two families, e.g. Levy processes. ...
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35 views

What is the Deterministic Traffic Generation Model?

I am studying Markov chains and queuing theory. I was curious about traffic generation models and actually happened to see the Deterministic Traffic Model, referred to as $D$ in Kendall's notation. ...
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Queue system with queue-triggered input process

I have a queue system, a classic system with an input generator, a queue and a servant. The servant is a $M$-servant with a certain serving rate $\mu$. The queue can contain an infinite number of ...
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Average time of permanence in a state of a Markov-chain

I know that in a Markov-chain the mean permanence time in a state is a random variable distributed accordingly to: Geometric distribution for Time Discrete Markov Chains Exponential distribution for ...
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22 views

Is the exit time independent of the state jumped to in a Markov chain?

Let $X$ be a continuous time Markov chain on a countable state space $S$, and let $\tau_n$ be the $n^{th}$ time at which the chain jumps out of a set $D$ (i.e. times $t$ at which, for some $\epsilon ...
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27 views

Markov renewal process vs Markov Jump process

The venerable wikipedia for "Markov renewal process" says that: "a Markov renewal process is a random process that generalizes the notion of Markov jump processes". So what's the definition of a ...
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16 views

How to compute the probability of a node given its Markov Blanket?

I'm trying to find P(a|b,e,~j,~m) in the image below. I think it's .3774, but when I try doing it by using the markov blanket formula (also in the picture) I get: P(a | b,e)*P(~j | a) * P(~m | a) = ...
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49 views

The difference between Dynamic Optimization, Stochastic Programming, Optimal control and Markov Decision Processes

I've seen the following terms thrown around somewhat interchangeably, and I'm confused. What are the distinctions between them, and what are some representative problems that each deals with? ...
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1answer
95 views

Elementary proof of geometric / negative binomial distribution in birth-death processes

The birth-death process concerns a population of $n_0$ individuals, each of which reproduce and die at a constant rate as time $t$ increases from $t=0$. Each individual splits into two individuals ...
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What is the importance of the infinitesimal generator of Brownian motion?

I have read that the infinitesimal generator of Brownian motion is $\frac{1}{2}\small\triangle$. Unfortunately, I have no background in semigroup theory, and the expositions of semigroup theory I have ...
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Finite state Markov chains and expectations

Let $X_t$ be a finite state Markov chain with generator matrix $Q$. For a give function $f(x)>0$ define: $$ u(t, i) = \mathbb{E}\left[\int_t^T f(X_s) \mathrm{d} s| X_t = i\right] $$ Are there any ...
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65 views

Expected number of steps between states in a Markov Chain

Suppose I am given a state space $S=\{0,1,2,3\}$ with transition probability matrix $\mathbf{P}= \begin{bmatrix} \frac{2}{3} & \frac{1}{3} & 0 & 0 \\[0.3em] \frac{2}{3} ...
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Poisson processes are the only renewal processes which are Markov Chains.

How would one prove the Proposition: "Poisson processes are the only renewal processes which are Markov Chains." A renewal process $N=(N(t))$ is a process for which $$N(t)=\max\{n : T_n \leq t\}$$ ...
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13 views

Invariant measure for gradient flows

I found here that a stochastic process from the SDE $dX_t=-\nabla V(X_t)dt + \sqrt{2 \beta^{-1}} dB_t $ has a unique invariant measure (if $V$ is suitable smooth), also called Gibbs distribution ...
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65 views

Exercise on Markov chain

Prove, or give an explicit counterexample to refute, the following assertion: if $\{X_n\}$ is a Markov chain, then $\{X_n^2\}$ is also a Markov chain. It's easy to show that ...
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Question about Markov chain

We know that if $\{X_n\}$ is a Markov chain, then $X_{n+1}$ is independent with the past states $X_0,\ldots,X_{n-1}$ given current state $X_n$, that is ...
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96 views

Markov chain problem with finite states

Consider any Markov chain on a state space with exactly $r$ states. We want to find the largest $N>0$ such that there exists states $i,j$ for every $n < N$ we have $p_{ij}^{(N)} > 0$ and ...