title: Scaling function for the critical diffusion coefficient of a critical fluid in a finite geometry.
abstract: The long-wavelength diffusion coefficient of a critical fluid confined between two parallel plates, separated by a distance L, is strongly affected by the finite size. Finite size scaling leads us to expect that the vanishing of the diffusion coefficient as xi(-1) for xi<<L, xi being the correlation length, would crossover to L-1 for xi>>L. We show that this is not strictly true. There is a logarithmic scaling violation. We construct a Kawasaki-like scaling function that connects the thermodynamic regime to the extreme critical (xi>>L) regime.
authors.affiliation: Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700 032, India.
authors.forename: Palash
authors.initials: P
authors.lastname: Das
authors.forename: Jayanta K
authors.initials: JK
authors.lastname: Bhattacharjee