Critical burstingK. Kumar1, P. Pal2 and S. Fauve3
1 Department of Physics and Meteorology, Indian Institute of Technology Kharagpur 721302, India
2 Kabi Sukanta Mahavidyalaya, Bhadreswar, District- Hooghly West Bengal 712221, India
3 Laboratoire de Physique Statistique, CNRS UMR 8550, ENS 24 rue Lhomond, 75005 Paris, France
received 3 January 2006; accepted in final form 19 April 2006
published online 17 May 2006
We present a deterministic mechanism to generate random bursts. It is illustrated using a low-dimensional dynamical system, derived for the problem of zero-Prandtl-number thermal convection, that shows a direct bifurcation from the motionless state to a time-dependent regime. The flow kinetic energy involves random peaks with power law histogram and frequency spectrum. We show that this results from the existence of exact exponentially growing solutions and propose this as an elementary deterministic mechanism to generate random bursts. Contrary to SOC models, we consider a low-dimensional continuous dynamical system without any prescribed threshold dynamics.
47.20.-k - Flow instabilities.
47.20.Lz - Secondary instabilities.
45.70.Ht - Avalanches.
© EDP Sciences 2006