arXiv subjects

Marco Zannetti

Publications and source records attributed to Marco Zannetti.

39 records · Page 3Linked to original sources

arXiv1996

The approach to scaling in phase-ordering kinetics

The influence of the initial fluctuations on the onset of scaling in the quench to zero temperature of a two dimensional system with conserved order parameter, is analyzed in detail with and without topological defects. We find that the initial fluctuations greatly affect the way scaling is reached, while the number of components of the order parameter does not play a significant role. Under strong initial fluctuations the preasymptotic linear behavior is replaced by the mean field behavior of the large-N model, producing the multiscaling to standard-scaling crossover also in the physically interesting cases of systems with a small number of components.

cond-mat↗

arXiv1995

Multiscaling to Standard Scaling Crossover in the Bray-Humayun Model for Phase Ordering Kinetics

The Bray-Humayun model for phase ordering dynamics is solved numerically in one and two space dimensions with conserved and non conserved order parameter. The scaling properties are analysed in detail finding the crossover from multiscaling to standard scaling in the conserved case. Both in the nonconserved case and in the conserved case when standard scaling holds the novel feature of an exponential tail in the scaling function is found.

cond-mat↗

arXiv1994

Scaling and Crossover in the Large-N Model for Growth Kinetics

The dependence of the scaling properties of the structure factor on space dimensionality, range of interaction, initial and final conditions, presence or absence of a conservation law is analysed in the framework of the large-N model for growth kinetics. The variety of asymptotic behaviours is quite rich, including standard scaling, multiscaling and a mixture of the two. The different scaling properties obtained as the parameters are varied are controlled by a structure of fixed points with their domains of attraction. Crossovers arising from the competition between distinct fixed points are explicitely obtained. Temperature fluctuations below the critical temperature are not found to be irrelevant when the order parameter is conserved. The model is solved by integration of the equation of motion for the structure factor and by a renormalization group approach.

cond-mat↗