Moderat
Reputation
1,531
Top tag
Next privilege 2,000 Rep.
 Sep 12 comment Last two digits of $3^{400}$ I have seen it before, but it was not discussed in this class, which makes me think that we are supposed to do this simply using the basics of modular arithmetic? Sep 12 asked Last two digits of $3^{400}$ Sep 9 comment Proving a non-stopping time For $\mathbf{X} = \{X_n : n \ge 0\}$ a stochastic process, a stopping time $T$ is a random time such that for each $n \ge 0$, the event $\{T = n\}$ is completely determined by (at most) the total information known up to time n, $\{X_0, \dots, X_n\}$. I know how to informally state that $W_y$ is not a stopping time (because it depends on a time $X_n \notin \{X_0, \dots, X_{n-1}\}$ but I'm not sure how to formally prove/state this. Sep 9 asked Proving a non-stopping time Sep 7 comment Verifying prime factorization equivalence class A perfect answer. Thank you. Sep 7 accepted Verifying prime factorization equivalence class Sep 7 asked Verifying prime factorization equivalence class Sep 5 accepted Proving that $X_n$ is (or is not) a Markov Chain Sep 5 comment Proving that $X_n$ is (or is not) a Markov Chain So for $X_n=1$, should I construct a counter example where we incorrectly predict the value of $X_{n+1}$ based only on $X_n$? Showing that we need the previous two states, not just previous 1? Sep 5 comment Proving that $X_n$ is (or is not) a Markov Chain @AndreaColonna What are you implying about the answer? Sep 4 comment Proving that $X_n$ is (or is not) a Markov Chain It just occurred to me that I might try making a table of all differing values x_n+1 can assume given x_n at a certain value. Sep 4 accepted How to show that the $k$th return to $y$ is a stopping time Sep 4 comment How to show that the $k$th return to $y$ is a stopping time So you mean that the event that $T_y^k$ is greater than $n$? If so, I understand thank you Sep 4 asked Proving that $X_n$ is (or is not) a Markov Chain Sep 4 comment How to show that the $k$th return to $y$ is a stopping time Sorry, I'm new to Markov chains, can you clarify what you mean by this? Sep 4 revised How to show that the $k$th return to $y$ is a stopping time edited title Sep 4 revised Are all compact sets in $\Bbb R^n$, $G_\delta$ sets? formatting Sep 4 suggested approved edit on Are all compact sets in $\Bbb R^n$, $G_\delta$ sets? Sep 4 asked How to show that the $k$th return to $y$ is a stopping time Sep 1 revised Proving that $a,n$ and $b, n$ relatively prime implies $ab,n$ relatively prime corrected question