DiscMathMeeting: Battlezone

http://domino.mpi-sb.mpg.de/internet/events.nsf/c1256081005596d0c125605d007f8191/d5cb57e488bdce3ac125717000430f8a!OpenDocument

This time, we will try a slightly stricter moderation to prevent over-excessive discussions. In particular, we will have the talk in the conference format, then a short clarification of the content and then a discussion on the presentation itself.

Here is an abstract of the talk:

Jim Propp's rotor router model is a simple deterministic analogue of a
random walk. Instead of distributing chips randomly, it serves the
neighbors in a fixed order. We analyze the difference between Propp machine
and random walk on the infinite two-dimensional grid. We show that,
independent of the starting configuration, at each time, the number of chips
on each vertex deviates from the expected number of chips in the random walk
model by at most a constant c, which is 7.83 for clockwise rotor sequences
and 7.28 otherwise. This is the first result which demonstrates that the
order in which the neighbors are served makes a difference.