scholarly journals Constructive Study of Modulational Instability in Higher Order Korteweg-de Vries Equations

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 54 ◽  
Author(s):  
Elena Tobisch ◽  
Efim Pelinovsky

Our present study is devoted to the constructive study of the modulational instability for the Korteweg-de Vries (KdV)-family of equations u t + s u p u x + u x x x (here s = ± 1 and p > 0 is an arbitrary integer). For deducing the conditions of the instability, we first computed the nonlinear corrections to the frequency of the Stokes wave and then explored the coefficients of the corresponding modified nonlinear Schrödinger equations, thus deducing explicit expressions for the instability growth rate, maximum of the increment and the boundaries of the instability interval. A brief discussion of the results, open questions and further research directions completes the paper.

2021 ◽  
Vol 2 (3) ◽  
pp. 907-926
Author(s):  
Lihui Chen ◽  
Haifeng Hu ◽  
Yuzhou Chen ◽  
Jing Gao ◽  
Guohua Li

LSPR of Cu2−xS and the resulting plasmonic applications are summarized. Remaining open questions and further research directions are proposed.


10.37236/2028 ◽  
2012 ◽  
Vol 18 (2) ◽  
Author(s):  
Maria Madonia ◽  
Giuseppe Scollo

This paper addresses the problem of characterizing classes of pairs of binary trees of equal size for which a signed reassociation sequence, in the Eliahou-Kryuchkov sense, can be shown to exist, either with a size induction hypothesis (reducible pairs), or without it (solvable pairs). A few concepts proposed by Cooper, Rowland and Zeilberger, in the context of a language-theoretic approach to the problem, are here reformulated in terms of signed reassociation sequences, and some of their results are recasted and proven in this framework. A few strategies, tactics and combinations thereof for signed reassociation are introduced, which prove useful to extend the results obtained by the aforementioned authors to new classes of binary tree pairs. In particular, with reference to path trees, i.e. binary trees that have a leaf at every level, we show the reducibility of pairs where (at least) one of the two path trees has a triplication at the first turn below the top level, and we characterize a class of weakly mutually crooked path tree pairs that are neither reducible nor solvable by any previously known result, but prove solvable by appropriate reassociation strategies. This class also includes a subclass of mutually crooked path tree pairs. A summary evaluation of the achieved results, followed by an outline of open questions and future research directions conclude the paper.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Shuai Li ◽  
C. M. Wang ◽  
Z. Z. Du ◽  
Fang Qin ◽  
Hai-Zhou Lu ◽  
...  

AbstractThe classical and quantum Hall effects are important subjects in condensed matter physics. The emergent 3D quantum Hall effects and nonlinear Hall effect have attracted considerable interest recently, with the former elevating the quantum Hall effect to a higher dimension and the latter extending the Hall effect to higher-order responses. In this perspective, we briefly introduce these two new members of the Hall family and discuss the open questions and future research directions.


2007 ◽  
Vol 73 (2) ◽  
pp. 153-157 ◽  
Author(s):  
P.K. SHUKLA ◽  
NITIN SHUKLA ◽  
L. STENFLO

Abstract.We consider a kinetic modulational instability of broadband (random phase) magnetic-field-aligned circularly polarized dispersive Alfvén waves in plasmas. By treating random phase Alfvén waves as quasi-particles, we consider their nonlinear interactions with ion quasi-modes within the framework of the wave-kinetic and Vlasov descriptions. A nonlinear dispersion relation governing such interactions is derived and analyzed. An explicit expression for the kinetic modulational instability growth rate is presented. Our results can be of relevance to the nonlinear propagation of incoherent Alfvén waves, which have been frequently observed in interstellar media, in the solar corona and in the solar wind, as well as in the foreshock regions of planetary bow-shocks and laboratory plasmas.


2015 ◽  
Vol 93 (3) ◽  
pp. 271-277
Author(s):  
H. Alinejad ◽  
M. Mahdavi

The effects of dust temperature and energetic (nonthermal) ions are incorporated in the study of modulated instability of dust-acoustic (DA) waves in a dusty plasma containing warm adiabatic dust grains, isothermal electrons and hot ions obeying a nonthermal distribution. Based on the multiple space and time scales perturbation, a nonlinear Schrödinger equation is derived with a solution showing a new relationship between the modulated DA wave packets and ion nonthermality. It is shown that as the population of fast ions increases, the transition from stable dark envelope solitons to unstable ones shifts to the smaller wavelength regions. The instability growth rate reduces owing to the presence of nonthermal ions. It is also found that the effects of dust temperature and electron concentration modify the criteria for the modulational instability of DA waves. The results could be useful for understanding the properties of modulated wave packets and their evolution in space and laboratory dusty plasmas, such as those in and around the Earth’s foreshock.


Author(s):  
Avishalom Tor

This Handbook chapter examines the main distinct concerns facing the application of empirical behavioral evidence to antitrust law and economics—also known as “behavioral antitrust.” More than many (though not all) other legal fields, antitrust law is primarily concerned with the conduct of firms in markets rather than in individual behavior per se. Yet much of the empirical evidence that behavioral antitrust draws on concerns individual behavior outside the firm, often in nonmarket settings. Hence besides adducing additional, direct empirical evidence on behavioral phenomena within firms and markets, there is a need to determine when and how the behavioral evidence on human judgment and decision behavior more generally is informative for antitrust. To this end, the chapter considers the ways in which markets and firms shape behavior. Direct evidence and theoretical analysis both reveal these institutions variously to facilitate rationality and deviations from it. After illustrating the implications of the complex interaction among markets, firms, and the rationality of antitrust actors across different areas of the law and enforcement policy, the chapter concludes by sketching some important open questions and future research directions in behavioral antitrust.


1999 ◽  
Vol 62 (4) ◽  
pp. 367-388 ◽  
Author(s):  
M. L. BÉGUÉ ◽  
A. GHIZZO ◽  
P. BERTRAND ◽  
E. SONNENDRÜCKER ◽  
O. COULAUD

A semi-Lagrangian two-dimensional fully relativistic Vlasov code for multicomputer environments is developed to study trapped-particle dynamics in phase space induced by relativistic modulational and Raman instabilities. Attention is focused on the efficiency properties of the numerical scheme, which allows a very fine description of particle dynamics in phase space. Vlasov simulations show the appearance of coherent vortex structures as a result of the nonlinear saturation mechanism of the relativistic modulational instability. Growth rates are computed and found to be in good agreement with theoretical values obtained from the dispersion relation by Quesnel et al, [Phys. Plasmas4, 3358–3368 (1997)] and Guérin et al. [Phys. Plasmas2, 2807–2814 (1995)]. In the case of coupling between the relativistic modulational instability and two-plasmon decay, stochastic behaviour can be observed due to the competition between different plasmas waves.


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