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12 votes
3 answers
666 views

An "inchworm-like" random walk on an integer interval

Imagine I place $k$ stones on an infinite one-dimensional integer interval $Z$ s.t. no stone is more than some distance $d$ from any other stone. For example, if $d=1$ and $k = 5$, we might place the ...
AmberWave's user avatar
  • 121
11 votes
2 answers
1k views

Is there a differentiable random walk?

Is there a random walk which is differentiable or smooth? Like brownian motion except smoothed out on small distances. I was wondering if there is a "natural" or "canonical" analogue of brownian ...
user114084's user avatar
10 votes
4 answers
679 views

The min of the mean of iid exponential variables

Let $X_1, \ldots, X_n, \ldots$ be iid exponential random variables with mean 1. It is well-known that $\min_{1\le j < \infty} \frac{X_1 + \cdots + X_j}{j}$ follows the uniform distribution U(0,1). ...
John Wong's user avatar
  • 773
8 votes
2 answers
259 views

Particularities about the honeycomb lattice for the computation of connectivity constant

After reading the paper The connective constant of the honeycomb lattice equals $\sqrt{2+\sqrt{2}}$ by Hugo Duminil-Copin and Stanislav Smirnov (arXiv:1007.0575) published some time ago in Annals Math....
Johnny Cage's user avatar
  • 1,561
5 votes
1 answer
523 views

Scaling of First-passage times for Random Walk on integer lattices

Consider simple symmetric random walk $S_{n} = (S_{n}^{(1)},\dots, S_{n}^{(d)})$ on the d-dimensional integer lattice with starting point the origin. Let $\tau_{N}$ be the first time $S_{n}$ exits ...
John Lotos's user avatar
4 votes
1 answer
829 views

Probability that a "closable" self-avoiding random walk forms a polygon

Consider a self-avoiding random walk on an infinite graph (for concreteness, the grid of 2-dimensional lattice points $\mathbb{Z}^2$), in which on each step, the next position is chosen uniformly at ...
Mechanical snail's user avatar
2 votes
0 answers
193 views

If the operators $B_i'$ satisfy an inequality, prove that $B_1'+\dotsb+ B_n'$ also satisfies the same inequality

Related: On a deceptively tricky calculus problem. The way that Leonard Gross proves the log Sobolev inequality is in the following stages: He proves that for any operator $B$ that satisfies the log ...
matilda's user avatar
  • 90
1 vote
1 answer
385 views

How fast does this Gaussian random walk move away from the origin?

Suppose $z_i$ are IID zero-centered $d$-dimensional Gaussian random variables with unit-trace covariance $\Sigma$ and $g(z_i)$ is the sum of its components. Consider the following random walk: $$x_s=\...
Yaroslav Bulatov's user avatar
1 vote
1 answer
247 views

Arc Sine law for Random Walk conditioned to non-absorption or not?

Let $S_n$ be simple symmetric Random walk on the integers in $[-N,N]$ with states $N$ and $-N$ absorbing. Let $\tau$ be the time to absorption when $S_0 = 0$. Is the $E(S^{2}_{n}| \tau \geq n)$ known?...
John Lotos's user avatar
1 vote
1 answer
456 views

Random walk with gaussian increments - Probability that it falls below 0

Suppose $\{Z_{i}\}_{i=1,2,\ldots}$ are normally distributed (identically and independent) random variables with mean $\mu>0$ and positive variance $\sigma^{2}$. Suppose we want to calculate the ...
Babypopo's user avatar
0 votes
1 answer
183 views

Probability to cross dynamic boundary for 1D-random walk?

context: Imagine we have an evolving bit sequence (ex: 001011...) where the probability to get 0 or 1 is 1/2. n is the lengh of my sequence (the number of bits) I can make an analogy with random walk: ...
Jonathan's user avatar
0 votes
2 answers
3k views

Two dimensional brownian motion first passage time

Hello, I am looking for information on how to solve/compute first passage time for two dimensional Brownian motion. any papers, references, books or web links for study will be helpful. thanks ...
Lakshmi's user avatar
  • 21