Skip to main content

Timeline for Proving a non-stopping time

Current License: CC BY-SA 3.0

8 events
when toggle format what by license comment
Sep 15, 2012 at 9:54 comment added Stéphane Laurent You have understood my comment: I meant it is more clear to prove that $W_y$ is not a stopping time for an example (such as your example) instead of proving that $W_y$ is not a stopping time for the "generic case"
Sep 15, 2012 at 7:18 comment added Did Not sure I understand your comment but if one looks for an example where no W_y is a stopping time, then the simpler the better, hence, you could try (X_n) i.i.d. uniform on a finite set.
Sep 15, 2012 at 5:50 comment added Stéphane Laurent Thanks @did. That's true, in fact we are looking for a counter-example and we should define a specific Markov chain for which the stopping-time property fails to be true.
Sep 15, 2012 at 4:50 comment added Did Of course this proof is valid in the generic case. But it may happen that for some $x$, $X_2=y$ never happens, then $[W_y=1]=\varnothing$ hence, with respect to $\Pr_x$, the event $[W_y=1]$ does belong to $\mathcal F_1$.
Sep 10, 2012 at 9:54 history edited Stéphane Laurent CC BY-SA 3.0
deleted 3 characters in body
Sep 9, 2012 at 19:45 comment added Moderat This is rather more advanced than my class, but after looking up some terms, you have taught me quite a lot. +1
Sep 9, 2012 at 19:44 vote accept Moderat
Sep 9, 2012 at 18:08 history answered Stéphane Laurent CC BY-SA 3.0