English
Related papers

Related papers: Skewed Lorentzian pulses and exponential frequency…

200 papers

A stochastic model for intermittent fluctuations due to a super-position of uncorrelated Lorentzian pulses is presented. For constant pulse duration, this is shown to result in an exponential power spectral density for the stationary…

Plasma Physics · Physics 2017-03-08 O. E. Garcia , A. Theodorsen

Fluctuations due to a super-position of uncorrelated Lorentzian pulses with a random distribution of amplitudes and duration times are considered. These are demonstrated to be strongly intermittent in the limit of weak pulse overlap,…

Plasma Physics · Physics 2018-03-14 O. E. Garcia , A. Theodorsen

The auto-correlation function and the frequency power spectral density due to a super-position of uncorrelated exponential pulses are considered. These are shown to be independent of the degree of pulse overlap and thereby the intermittency…

Plasma Physics · Physics 2017-04-26 O. E. Garcia , A. Theodorsen

Turbulent motions due to flux-driven thermal convection is investigated by numerical simulations and stochastic modelling. Tilting of convection cells leads to the formation of sheared flows and quasi-periodic relaxation oscillations for…

Fluid Dynamics · Physics 2020-08-26 G. Decristoforo , A. Theodorsen , O. E. Garcia

A stochastic model is presented for a super-position of uncorrelated pulses with a random distribution of amplitudes, sizes, velocities and arrival times. The pulses are assumed to move radially with fixed shape and amplitudes decaying…

Plasma Physics · Physics 2023-05-10 J. M. Losada , A. Theodorsen , O. E. Garcia

A stochastic model for a super-position of uncorrelated pulses with a random distribution of and correlations between amplitudes and velocities is analyzed. The pulses are assumed to move radially with fixed shape and amplitudes decreasing…

Plasma Physics · Physics 2024-12-09 O. Paikina , J. M. Losada , A. Theodorsen , O. E. Garcia

A stochastic model for a superposition of uncorrelated pulses with a random distribution of amplitudes, sizes, and velocities is analyzed. The pulses are assumed to move radially with fixed shape and amplitudes decreasing exponentially in…

Plasma Physics · Physics 2024-01-11 J. M. Losada , O. Paikina , O. E. Garcia

A stochastic model for intermittent fluctuations in the scrape-off layer of magnetically confined plasmas has been constructed based on a super-position of uncorrelated pulses arriving according to a Poisson process. In the most common…

Plasma Physics · Physics 2018-05-04 Audun Theodorsen , Odd Erik Garcia

Recently, it has been proposed that the turbulent fluctuations measured in a linear plasma device could be described as a superposition of uncorrelated Lorentzian pulses with a narrow distribution of durations, which would provide an…

Plasma Physics · Physics 2012-09-11 B. Ph. van Milligen , R. Sánchez , C. Hidalgo

A well-known stochastic model for intermittent fluctuations in physical systems is investigated. The model is given by a super-position of uncorrelated exponential pulses, and the degree of pulse overlap is interpreted as an intermittency…

Plasma Physics · Physics 2018-01-17 Audun Theodorsen , Odd Erik Garcia

A mapping of nonextensive statistical mechanics into Gibbs' statistical mechanics exists, which leads to a generalization of Einstein's formula for fluctuations. A unified treatment of stability of relaxed states in nonextensive statistical…

Classical Physics · Physics 2018-01-30 Andrea Di Vita

Turbulence is generally associated with universal power-law spectra in scale ranges without significant drive or damping. Although many examples of turbulent systems do not exhibit such an inertial range, power-law spectra may still be…

Fluid Dynamics · Physics 2015-06-16 Vasil Bratanov , Frank Jenko , David Hatch , Michael Wilczek

The dispersion characteristics of an circularly polarized electromagnetic wave of arbitrary amplitude, propagating in a highly (thermally and kinematically) relativistic plasma, are shown to approach those of a linear wave in an…

Plasma Physics · Physics 2018-07-17 Swadesh Mahajan , Manasvi Lingam

Statistical fluctuations of the light emitted from amplifying random media are studied theoretically and numerically. The characteristic scales of the diffusive motion of light lead to Gaussian or power-law (Levy) distributed fluctuations…

Fluctuations in the boundary region of the Alcator C-Mod tokamak have been analyzed using gas puff imaging data from a set of Ohmically heated plasma density scan experiments. It is found that the relative fluctuation amplitudes are modest…

Plasma Physics · Physics 2017-09-13 A. Theodorsen , O. E. Garcia , R. Kube , B. LaBombard , J. L. Terry

Relativistic magnetically dominated turbulence is an efficient engine for particle acceleration in a collisionless plasma. Ultrarelativistic particles accelerated by interactions with turbulent fluctuations form non-thermal power-law…

Plasma Physics · Physics 2023-06-14 Cristian Vega , Stanislav Boldyrev , Vadim Roytershteyn

We present an exact calculation of the power spectrum of the electromagnetic fluctuations in a relativistic equilibrium plasma described by Maxwell-J\"uttner distribution functions. We consider the cases of wave vectors parallel or normal…

Plasma Physics · Physics 2013-12-06 C. Ruyer , L. Gremillet , D. Bénisti , G. Bonnaud

Single-point measurements of fluctuations in the scrape-off layer of magnetized plasmas are generally found to be dominated by large-amplitude bursts which are associated with radial motion of blob-like structures. A stochastic model for…

Plasma Physics · Physics 2013-05-30 O. E. Garcia

We study cumulative scattering effects on wave front propagation in time dependent randomly layered media. It is well known that the wave front has a deterministic characterization in time independent media, aside from a small random shift…

Analysis of PDEs · Mathematics 2016-01-20 Liliana Borcea , Knut Solna

Strong frequency dependence is unlikely in diffusive or over-damped systems. When exceptions do occur, such as in the case of stochastic resonance, it signals an interesting underlying phenomenon. We find that such a case appears in the…

Statistical Mechanics · Physics 2015-12-11 Ayse Ferhan Yesil , M. Cemal Yalabik
‹ Prev 1 2 3 10 Next ›