Iteration of Mandelbrot cascades

Seminar: 
Applied Mathematics
Event time: 
Tuesday, April 22, 2014 - 12:00pm to 1:00pm
Location: 
AKW 200
Speaker: 
Jacques Peyriere
Speaker affiliation: 
Université Paris-Sud (France)
Event description: 

The Mandelbrot cascade constructed from a random variable W of expectation 1, when non degenerate, provides a new variable Y of expectation 1. The law of Y depends only on the law of W, so Mandelbrot cascades can be viewed as a mapping T from probability distributions to probability distributions. Starting from a suitable distribution, this mapping can be iterated. This gives rise to a Central Limit Theorem.

When dealing with Mandelbrot cascades in a random environment new phenomena occur. One has to distinguish two regimes:

1) The conservative case for which there is a CLT, which can be non-standard.

2) In the non-conservative case the map T has a unique fixed point which is also a fixed point of some kind of smoothing transformation.