Do you want to publish a course? Click here

Peaked structures in noise power spectra as signature of avalanche correlation

102   0   0.0 ( 0 )
 Publication date 2006
  fields Physics
and research's language is English




Ask ChatGPT about the research

An outstanding topic on noise phenomena is the occurrence of peaked structures in many natural systems in a wide range 10^-1 - 10^6 Hz. All existing theories failed to explain this issue. The present theory based on first prin-ciple statistics of elementary events clustered in time-amplitude correlated large avalanches leads to a noise spectral power master equation suitable for any peaked noise spectra. The excellent agreement with our current noise experiments in high Tc superconductors in the dendritic regime and with optical noise experiments in E.coli demonstrates firstly that avalanche correlation is the physical source of spectral peaks.



rate research

Read More

We theoretically study energy pumping processes in an electrical circuit with avalanche diodes, where non-Gaussian athermal noise plays a crucial role. We show that a positive amount of energy (work) can be extracted by an external manipulation of the circuit in a cyclic way, even when the system is spatially symmetric. We discuss the properties of the energy pumping process for both quasi-static and fnite-time cases, and analytically obtain formulas for the amounts of the work and the power. Our results demonstrate the significance of the non-Gaussianity in energetics of electrical circuits.
Crackling noise is a common feature in many dynamic systems [1-9], the most familiar instance of which is the sound made by a sheet of paper when crumpled into a ball. Although seemingly random, this noise contains fundamental information about the properties of the system in which it occurs. One potential source of such information lies in the asymmetric shape of noise pulses emitted by a diverse range of noisy systems [8-12], but the cause of this asymmetry has lacked explanation [1]. Here we show that the leftward asymmetry observed in the Barkhausen effect [2] - the noise generated by the jerky motion of domain walls as they interact with impurities in a soft magnet - is a direct consequence of a magnetic domain walls negative effective mass. As well as providing a means of determining domain wall effective mass from a magnets Barkhausen noise our work suggests an inertial explanation for the origin of avalanche asymmetries in crackling noise phenomena more generally.
The impact of bound states in Landauer-Buttiker scattering approach to non-equilibrium quantum transport is investigated. We show that the noise power at frequency $ u$ is sensitive to all bound states with energies $omega_b$ satisfying $|omega_b| < u$. We derive the exact expression of the bound state contribution and compare it to the one produced by the scattering states alone. It turns out that the bound states lead to specific modifications of both space and frequency dependence of the total noise power. The theoretical and experimental consequences of this result are discussed.
Financial correlation matrices measure the unsystematic correlations between stocks. Such information is important for risk management. The correlation matrices are known to be ``noise dressed. We develop a new and alternative method to estimate this noise. To this end, we simulate certain time series and random matrices which can model financial correlations. With our approach, different correlation structures buried under this noise can be detected. Moreover, we introduce a measure for the relation between noise and correlations. Our method is based on a power mapping which efficiently suppresses the noise. Neither further data processing nor additional input is needed.
As a solvable and broadly applicable model system, the totally asymmetric exclusion process enjoys iconic status in the theory of non-equilibrium phase transitions. Here, we focus on the time dependence of the total number of particles on a 1-dimensional open lattice, and its power spectrum. Using both Monte Carlo simulations and analytic methods, we explore its behavior in different characteristic regimes. In the maximal current phase and on the coexistence line (between high/low density phases), the power spectrum displays algebraic decay, with exponents -1.62 and -2.00, respectively. Deep within the high/low density phases, we find pronounced emph{oscillations}, which damp into power laws. This behavior can be understood in terms of driven biased diffusion with conserved noise in the bulk.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا