Question: 5.5 Let {X n } be a random walk for which zero is an absorbing state and such that from a positive state, the process
5.5 Let {Xn} be a random walk for which zero is an absorbing state and such that from a positive state, the process is equally likely to go up or down one unit. The transition probability matrix is given by (5.9) with r0 = 1 and p, = q; = ; for i ? 1.
(a) Show that {Xn} is a nonnegative martingale.
(b) Use the maximal inequality II, (5.7) to limit the probability that the process ever gets as high as N > 0.
Step by Step Solution
There are 3 Steps involved in it
Get step-by-step solutions from verified subject matter experts
