Y. Huang et al., SPONTANEOUS GENERATION OF DISCRETE SCALE-INVARIANCE IN GROWTH-MODELS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 55(6), 1997, pp. 6433-6447
We suggest that the short-wavelength Mullins-Sekerka instability, toge
ther with strong screening effects, generate spontaneously a discrete
scale invariance (DSI) in growth processes. A signature of this DSI is
the presence of log-periodic oscillations correcting the usual power
laws. This is confirmed by extensive numerical simulations on the need
le model, using various growth rules (diffusion-limited aggregation, a
ngle screening, eta model, and crack approximation) on systems contain
ing up to 5000 needles, and by some experimental data on geological cr
acks.