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 49551
2 votes
1 answer
421 views

Random walk always stays below a level $a$

Suppose we have a random walk $S_n$ with i.i.d. steps $X_i$. We assume that $$\mathbb{E}[X_i] = -\mu, \text{Var}[X_i] = 1,$$ where $\mu$ is close (or going) to zero. We also assume that the moment gen …
Xiao's user avatar
  • 485
6 votes
0 answers
146 views

Running minimum of exponential random walks

Let $\{X_i\}$ be a collection of i.i.d. Exp$(1)$ random variables. For $k \in \mathbb{Z}_{>0}$, define $$S_k = \sum_{i=1}^k X_i$$ and note that $\mathbb{E}[S_k] = k$. I was wondering if there is any w …
Xiao's user avatar
  • 485
2 votes
1 answer
222 views

Maximum of sums of iid $X_i$'s where $X_i$ is the difference of two exponential r.v

Given $X_i = A_i - B_i$ where $A_i\sim \text{ Exp}(\alpha)$ and $B_i \sim \text{ Exp}(\lambda)$. Define $S_k = \sum_{i=1}^k X_i$ with $S_0 = 0$, and $$M_n = \max_{1\leq k \leq n} S_k.$$ Is it possibl …
Xiao's user avatar
  • 485