Course in Stochastics in Autumn 2002


   Stefan Geiss

   Stochastic Processes and Applications

   Time and Place : Monday    10-12 MaD 381
                    Wednesday 10-12 MaD 381
   First lecture  : 9/09/2002

   Description:

   Assume that You have a fair coin and play the following game:
   You and a second player have a starting capital of about 100
   Euro. The coin will be flipped and if You have the tail, then
   You get 1 Euro from the other player, in the other case You have
   to give her or him 1 Euro. One may ask the following questions:

   [Q1] What can You say about the length of the game, if You assume
        that the game ends if You or Your partner has lost all the
        money?
   [Q2] What is the probability that the game never ends?

   If the coin is not fair, which may happen, one should ask:

   [Q3] What is the probability that You loose all Your money before
        Your partner looses all her or his money?

   The course will answer these questions. For example [Q1] is related
   to the beautiful and surprising Law of Iterated Logarithm.

   Contents of the course:

    1. Sums of independent random variables
       (Zero-One Laws and applications to random walks,
       Strong law of large numbers, Law of iterated logarithm)
    2. Martingale theory
       (Fundamental inequalities according to Doob and Burkholder-Davis-Gundy,
       Limit theorems for uniformly integrable martingales)
    3. Applications (Stochastic models)

   Literature:

    D. Williams: Probability with Martingales (Cambridge)
    A.N. Sirjaev: Probability (Springer)

   Examination_1
   Examination_2