scholarly journals Linear dispersion relation of geodesic acoustic modes driven by trapped and circulating energetic particles – CORRIGENDUM

2021 ◽  
Vol 87 (6) ◽  
Author(s):  
I. Chavdarovski ◽  
M. Schneller ◽  
A. Biancalani
Author(s):  
Quentin Fontaine ◽  
Agostino Apra ◽  
Giovanni Lerario ◽  
Elisabeth Giacobino ◽  
Alberto Bramati ◽  
...  

2010 ◽  
Vol 77 (3) ◽  
pp. 357-365 ◽  
Author(s):  
B. DASGUPTA ◽  
DASTGEER SHAIKH ◽  
P. K. SHUKLA

AbstractWe derive a generalized linear dispersion relation of waves in a strongly magnetized, compressible, homogeneous and isotropic quasi-neutral plasma. Starting from a two-fluid model, describing distinguishable electron and ion fluids, we obtain a six-order linear dispersion relation of magnetized waves that contains effects due to electron and ion inertia, finite plasma beta and angular dependence of phase speed. We investigate propagation characteristics of these magnetized waves in a regime where scale lengths are comparable with electron and ion inertial length scales. This regime corresponds essentially to the solar wind plasma, where length scales, comparable with ion cyclotron frequency, lead to dispersive effects. These scales in conjunction with linear waves present a great deal of challenges in understanding the high-frequency, small-scale dynamics of turbulent fluctuations in the solar wind plasma.


2015 ◽  
Vol 766 ◽  
pp. 326-336 ◽  
Author(s):  
Tore Magnus A. Taklo ◽  
Karsten Trulsen ◽  
Odin Gramstad ◽  
Harald E. Krogstad ◽  
Atle Jensen

AbstractWe report laboratory experiments and numerical simulations of the Zakharov equation, designed to have sufficient resolution in space and time to measure the dispersion relation for random surface gravity waves. The experiments and simulations are carried out for a JONSWAP spectrum and Gaussian spectra of various bandwidths on deep water. It is found that the measured dispersion relation deviates from the linear dispersion relation above the spectral peak when the bandwidth is sufficiently narrow.


2017 ◽  
Vol 31 (05) ◽  
pp. 1750045
Author(s):  
Yizhe Yuan ◽  
Xiaoyong Guo ◽  
Liqun An ◽  
Wen Xu

We present a theoretical study on graphene-semiconductor planar structures. The frequency of the photonic modes in the structure, which can be efficiently tuned via varying the sample parameters, is within the terahertz (THz) bandwidth. Furthermore, it is found that a roughly linear dispersion relation can be obtained for photonic modes in the THz region. Hence, the proposed graphene-semiconductor planar structures can be served as THz waveguide with desirable transmission characteristics.


1982 ◽  
Vol 49 (2) ◽  
pp. 284-290 ◽  
Author(s):  
A. D. D. Craik

The development of three-dimensional localized disturbances in unstable flows was recently studied by Craik [1] using a model dispersion relation. The adoption of such an approximate formula for the linear dispersion relation allows a dramatic reduction in computational effort, in comparison with more precise calculations (e.g., Gaster [3], [5]), yet may still yield quite accurate results. Craik [1] gives simple analytical solutions for various limiting cases of his chosen model. Here, this model is further investigated. Numerical results are given which are free of previous scaling assumptions and the accuracy of the proposed model is assessed by comparison with known exact computations for plane Poiseuille flow. Certain improvements are made by including further terms in the model dispersion relation and the influence of these additional terms is determined. A further model is investigated which yields “splitting” of the wave packet into two regions of greatest amplitude, one on either side of the axis of symmetry. Such behavior may be characteristic of many flows at sufficiently large Reynolds numbers. Extension of this work to three-dimensional and slowly varying flows seems a practical possibility.


1972 ◽  
Vol 7 (1) ◽  
pp. 13-48 ◽  
Author(s):  
T. D. Rognlien ◽  
S. A. Self

A treatment is given of the problem of constructing normal modes for anarbitrarily bounded system from roots of the linear dispersion relationD( ω, k) = 0 for the corresponding infinite or periodically bounded system. For a system described by continuous macroscopic variables, and of general cylindrical form (uniform along an axisz, say), each transverse eigenmode gives rise to a set of axial normal modes constructed from a pair of dominant rootskαz(ω) ofD= 0 satisfying the boundary conditions which are characterized by complex reflexion coefficients for the dominant waves. The implications of the results for the interpretation of experiments on plasma waves and instabilities on finite cylinders are discussed, with particular reference to the effects of end-plate damping and axial current onQ-machines.


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