Speaker
Wolfhard Janke
(Institute for Theoretical Physics, Leipzig)
Description
The loop-gas approach to lattice field theory provides an
alternative, geometrical description in terms of linelike
objects. The resulting statistical random-graph ensemble
composed of loops and chains can be efficiently generated by
Monte Carlo simulations using the so-called "worm" update
algorithm. Concepts from percolation theory and the theory
of self-avoiding random walks are used to describe
estimators of physical observables that utilize the nature
of the worm algorithm. The fractal structure of the random
loops and chains as well as their scaling properties are
studied. The general approach is illustrated for the O(1)
loop model, or high-temperature series expansion of the
Ising model, on a honeycomb lattice, with its known exact
results for some
quantitites providing valuable benchmarks.
