Colloquium
12:30 p.m., Thursday (February 9, 2006)
MATH 104
Andrew Rechnitzer
University of Melbourne
The analytic structure of lattice models  looking inside unsolved problems
What it means for a problem to be "solved" really depends on who you
talk to; you can square the circle if you are happy to use more than a
ruler and compass. In this talk, I will describe work that has lead to
"unsolvability" results for a wide class of combinatorial problems
that arise in statistical physics.
The starting point for these results are techniques which allow us to
peek inside the solutions of these problems without actually having to
solve them. The structure of the solutions proves that they do not
belong to the most pervasive class of functions in mathematical
physics, so called differentiablyfinite functions. This, in turn,
shows that the models cannot be solved using many traditional
combinatorial methods.
Refreshments will be served at 12:15 p.m. (MATX 1115, Math Lounge).
