most recent 30 from http://mathoverflow.net 2013-06-19T21:46:19Z http://mathoverflow.net/feeds/question/106257 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/106257/hitting-time-of-a-subset Igor Rivin 2012-09-03T16:20:38Z 2012-09-03T16:26:37Z

<p>Suppose you have the simple random walk on $L=\mathbb{Z}^n,$ and $A \subset L$ is a subset (in my case, the subset is a union of hyperplanes, so in particular infinite). There is a random variable $T(A)$ -- the expected time to get from the origin to $A.$ The question is: is there some standard technology to upper bound the expectation of $T(A)?$ Any particularly recommended things to read? </p>