Anjan Prasad Gantapara
|Phone:||+49 711 685-67606|
|Fax:||+49 711 685-63658|
|Email:||Anjan.Gantapara _at_ icp.uni-stuttgart.de|
|Address:||Anjan Prasad Gantapara|
Institute for Computational Physics
Prof. Dr. Rudolf Hilfer
A high precision multi-canonical Monte Carlo method is developed. This multi-canonical method is employed for the computation of exact order parameter distributions for the two dimensional Ising model. The extraction of universal behavior from finite size functions still remains of interest. Various boundary conditions have been taken into account.The order parameter distributions for finite lattice sizes up to 128 at temperatures above, below, and at the critical point are computed. All the results are fully converged with respect to the number of Monte Carlo steps. For critical systems the approach to the Gaussian behavior is generally slow. For large system sizes the fat tails observed in Ref  are found to appear also for temperatures approaching critical point from below. The effect of the boundary conditions at criticality in the far tail regime are studied with high precision. Currently we are marching towards lattice size 256. Hilfer R, Biswal B, Mattutis H G, and Janke W Phys. Rev. E 68,046123 (2003).