We characterize the spectral properties of weak turbulence in a liquid crystal sample driven by an external electric field, as a function of the applied voltage, and we find a 1=f noise spectrum S(f) = 1/f^n within the whole range 0 < n < 2. We theoretically explore the hypothesis that the system complexity is driven by non-Poisson events resetting the system through creation and annihilation of coherent structures, retaining no memory of previous history (crucial events). We study the time asymptotic regime by means of the density psi(t) of the time distances between two crucial events, yielding n = 3 - m, where m is defined through the long-time form psi(t) = 1/t^m, with 1 < m < 3. The system regression to equilibrium after an abrupt voltage change experimentally confirms the theory, proving violations of the ordinary linear response theory for both n > 1 and n < 1.
Event-driven power-law relaxation in weak turbulence / Silvestri L.; Fronzoni L.; Grigolini P.; Allegrini P.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - ELETTRONICO. - 102:(2009), pp. 014502-014502. [10.1103/PhysRevLett.102.014502]
Event-driven power-law relaxation in weak turbulence
Silvestri L.;
2009
Abstract
We characterize the spectral properties of weak turbulence in a liquid crystal sample driven by an external electric field, as a function of the applied voltage, and we find a 1=f noise spectrum S(f) = 1/f^n within the whole range 0 < n < 2. We theoretically explore the hypothesis that the system complexity is driven by non-Poisson events resetting the system through creation and annihilation of coherent structures, retaining no memory of previous history (crucial events). We study the time asymptotic regime by means of the density psi(t) of the time distances between two crucial events, yielding n = 3 - m, where m is defined through the long-time form psi(t) = 1/t^m, with 1 < m < 3. The system regression to equilibrium after an abrupt voltage change experimentally confirms the theory, proving violations of the ordinary linear response theory for both n > 1 and n < 1.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.