Target and trapping problems: From the ballistic to the diffusive regime

1999 ◽  
Vol 110 (2) ◽  
pp. 1112-1122 ◽  
Author(s):  
A. M. Berezhkovskii ◽  
D. J. Bicout ◽  
G. H. Weiss
Keyword(s):  
Diffusive Regime ◽  
Trapping Problems

scholarly journals Electromagnetic Waves Through Disordered Systems: Comparison of Intensity, Transmission and Conductance

2001 ◽  
Vol 694 ◽  
Author(s):  
Fredy R Zypman ◽  
Gabriel Cwilich
Keyword(s):  
Probability Distribution ◽  
Disordered Systems ◽  
Electromagnetic Waves ◽  
Delta Function ◽  
Rayleigh Distribution ◽  
Dirac Delta Function ◽  
Universal Form ◽  
Dirac Delta ◽  
Diffusive Regime ◽  
Analytical Expressions

AbstractWe obtain the statistics of the intensity, transmission and conductance for scalar electromagnetic waves propagating through a disordered collection of scatterers. Our results show that the probability distribution for these quantities x, follow a universal form, YU(x) = xne−xμ. This family of functions includes the Rayleigh distribution (when α=0, μ=1) and the Dirac delta function (α →+ ∞), which are the expressions for intensity and transmission in the diffusive regime neglecting correlations. Finally, we find simple analytical expressions for the nth moment of the distributions and for to the ratio of the moments of the intensity and transmission, which generalizes the n! result valid in the previous case.

scholarly journals Run-and-tumble bacteria slowly approaching the diffusive regime

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
Andrea Villa-Torrealba ◽  
Cristóbal Chávez-Raby ◽  
Pablo de Castro ◽  
Rodrigo Soto
Keyword(s):  
Diffusive Regime ◽  
Run And Tumble

scholarly journals Acoustic Detection of Oceanic Double-Diffusive Convection: A Feasibility Study

2010 ◽  
Vol 27 (3) ◽  
pp. 580-593 ◽  
Author(s):  
Tetjana Ross ◽  
Andone Lavery
Keyword(s):  
Acoustic Scattering ◽  
Double Diffusive Convection ◽  
Western Antarctic Peninsula ◽  
Acoustic Detection ◽  
Acoustic Backscattering ◽  
Diffusive Regime ◽  
Diffusive Convection ◽  
In Situ Observations ◽  
Double Diffusive

Abstract The feasibility of using high-frequency acoustic scattering techniques to map the extent and evolution of the diffusive regime of double-diffusive convection in the ocean is explored. A scattering model developed to describe acoustic scattering from double-diffusive interfaces in the laboratory, which accounted for much of the measured scattering in the frequency range from 200 to 600 kHz, is used in conjunction with published in situ observations of diffusive-convection interfaces to make predictions of acoustic scattering from oceanic double-diffusive interfaces. Detectable levels of acoustic scattering are predicted for a range of different locations in the world’s oceans. To corroborate these results, thin acoustic layers detected near the western Antarctic Peninsula using a multifrequency acoustic backscattering system are shown to be consistent with scattering from diffusive-convection interfaces.

scholarly journals Mean field limits for interacting Hawkes processes in a diffusive regime

Bernoulli ◽  
2022 ◽  
Vol 28 (1) ◽  
Author(s):  
Xavier Erny ◽  
Eva Löcherbach ◽  
Dasha Loukianova
Keyword(s):  
Mean Field ◽  
Hawkes Processes ◽  
Diffusive Regime ◽  
Mean Field Limits

Probing Conductive Masses in the Diffusive Regime - Equivalent Sources and Bodies

1999 ◽  
Author(s):  
G. Perrusson ◽  
B. Bourgeois ◽  
D. Lesselier ◽  
M. Lambert ◽  
B. Duchene
Keyword(s):  
Diffusive Regime ◽  
Equivalent Sources

scholarly journals Monte Carlo Investigation of Shot-noise Suppression in Nondegenerate Ballistic and Diffusive Transport Regimes

2000 ◽  
Vol 53 (1) ◽  
pp. 3 ◽  
Author(s):  
L. Reggiani ◽  
A. Reklaitis ◽  
T. González ◽  
J. Mateos ◽  
D. Pardo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Active Region ◽  
Inelastic Scattering ◽  
Shot Noise ◽  
Noise Suppression ◽  
Signal To Noise Ratio ◽  
Diffusive Transport ◽  
Poisson Solver ◽  
Diffusive Regime ◽  
Shot Noise Suppression

We review recent theoretical investigations of shot-noise suppression in nondegenerate semiconductor structures surrounded by two contacts acting as thermal reservoirs. Calculations make use of an ensemble Monte Carlo simulator self-consistently coupled with a one-dimensional Poisson solver. By taking the doping of the injecting contacts and the applied voltage as variable parameters, the influence of elastic and inelastic scattering as well as of tunneling between heterostructures in the active region is investigated. In the case of a homogeneous structure at T = 300 K the transition from ballistic to diffusive transport regimes under different contact injecting statistics is analysed and discussed. Provided significant space-charge effects take place inside the active region, long-range Coulomb interaction is found to play an essential role in suppressing shot noise at applied voltages much higher than the thermal value. In the elastic diffusive regime, momentum space dimensionality is found to modify the suppression factor γ, which within numerical uncertainty takes values respectively of about ⅓, ½ and 0·7 in the 3D, 2D and 1D cases. In the inelastic diffusive regime, shot noise is suppressed to the thermal value. In the case of single and multiple barrier non-resonant heterostructures made by GaAs/AlGaAs at 77 K, the mechanism of suppression is identified in the carrier inhibition to come back to the emitter contact after having been reflected from a barrier. This condition is realised in the presence of strong inelastic scattering associated with emission of optical phonons. At increasing applied voltages for a two-barrier structure, shot noise is suppressed up to about a factor of 0·50 in close analogy with the corresponding resonant barrier-diode. For an increasing number of barriers, shot noise is found to be systematically suppressed to a more significant level by following approximately a 1/(N + 1) behaviour, N being the number of barriers. This mechanism of suppression is expected to conveniently improve the signal-to-noise ratio of these devices.

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