IMT Institutional Repository: No conditions. Results ordered -Date Deposited. 2024-03-28T23:01:10ZEPrintshttp://eprints.imtlucca.it/images/logowhite.pnghttp://eprints.imtlucca.it/2012-02-24T13:39:36Z2012-02-24T13:39:36Zhttp://eprints.imtlucca.it/id/eprint/1178This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11782012-02-24T13:39:36ZRandomly pinned landscape evolutionA simple scheme for the evolution of a fluvial landscape in heterogeneous environments is critically examined to capture the essential mechanism responsible for the recurrent scale-free landforms in the river basin. It is shown that, regardless of boundary and initial conditions, geomorphological constraints in the form of quenched randomly pinned regions play a key role in the robust emergence of aggregation patterns with a scaling behavior in agreement with that of real river basins. Guido Caldarelliguido.caldarelli@imtlucca.itAchille GiacomettiAmos MaritanIgnacio Rodriguez-IturbeAndrea Rinaldo2012-02-24T12:56:03Z2013-11-20T13:19:15Zhttp://eprints.imtlucca.it/id/eprint/1172This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11722012-02-24T12:56:03ZStationary self-organized fractal structures in an open, dissipative electrical systemWe study the stationary state of a Poisson problem for a system of N perfectly conducting metal balls driven by electric forces to move within a medium of very low electrical conductivity onto which charges are sprayed from outside. When grounded at a confining boundary, the system of metal balls is experimentally known to self-organize into stable fractal aggregates. We simulate the dynamical conditions leading to the formation of such aggregated patterns and analyse the fractal properties. From our results and those obtained for steady-state systems that obey minimum total energy dissipation (and potential energy of the system as a whole), we suggest a possible dynamical rule for the emergence of scale-free structures in nature. Marco MaraniJayanth R BanavarGuido Caldarelliguido.caldarelli@imtlucca.itAmos MaritanAndrea Rinaldo