AS100 (Large Deviations)

Fall 2009, Block 1

 

Course Description: The study of rare events occupies an important part in many probabilistic analyses. While there are many types of rare events, the theory of exponentially small events deserves a special consideration. In this course we will develop the mathematical background for exploring the subject of large deviations, which studies the structure and transformations of such exponentially small events. We will start with a study of how quickly the law of large numbers holds, then develop some general theories, such as the Gartner-Ellis theorem, the contraction principle and Varadhan's lemma, and then apply them in a number of ways. For example, we will give precise estimates of large deviations for a sequence of independent random variables (Cramer's theorem). If time permits, we will also study rare events that depend on random processes, e.g., brownian motion. Along the way, we describe how entropy plays a central role in the calculation of probabilities of large deviations. A more concrete approach to the subject, based on applications to finance and actuarial science will be given the corresponding course 'Topics in large deviations and finance' in Block 3.

 

Lectures and Exercise Sessions with Magdalena Musat (musat@math.ku.dk) : Mondays 15-17 (Aud. 7) and Wednesdays 9-10 (Room 109), 10-12 (Aud. 3).

     

      

 

Course Information

 

Lecture Notes

 

Mandatory Assignments