Laplacian growth with separately controlled noise and anisotropy - art. no. 061102

Conformal mapping models are used to study the competition of noise and ani sotropy in Laplacian growth. For this purpose, a family of models is introd uced with the noise level and directional anisotropy controlled independent ly. Fractalization is observed in both anisotropic growth and growth with v arying noise. The fractal dimension is determined from the cluster size sca ling with cluster area. For isotropic growth d=1.7, at both high and low no ise. For anisotropic growth with reduced noise the dimension can be as low as d=1.5 and apparently is not universal. Also, we study the fluctuations o f particle areas and observe, in agreement with previous studies, that exce ptionally large particles may appear during growth, leading to pathological ly irregular clusters. This difficulty is circumvented by using an acceptan ce window for particle areas.