Electrostatic rogue waves in double pair plasmas

Abstract

A nonlinear Schrödinger equation is derived to investigate the modulational instability (MI) of ion-acoustic (IA) waves (IAWs) in a double pair plasma system containing adiabatic positive and negative ion fluids along with super-thermal electrons and positrons. The analytical analysis predicts two types of modes, viz. fast (ω f ) and slow (ω s ) IA modes. The possible stable and unstable parametric regions for the IAWs in presence of external perturbation can be observed for both ω f and ω s . The number density of the negative ions and positrons play a vital role in generating the IA rogue waves (IARWs) in the modulationally unstable region. The applications of our present work in astrophysical environments [viz. D-region (H + , O − 2 ) and F-region (H + , H − ) of the Earth's ionosphere] as well as in laboratory plasmas [viz. pair-ion Fullerene (C + , C − )] are pinpointed.

Dust‐acoustic envelope solitons in super‐thermal plasmas

“…Figure describes that the stable (unstable) domain of the DAWs increases with an increase in the value of the ion (electron) temperature (via σ 4 = T i / T e ). The instability criterion of the DAWs for super‐thermality of electrons, positrons, and ions in four component EPID plasma can be observed in Figure , and it can be seen from this figure that (a) when for κ = 1.8, 2.0, and 2.2 the corresponding k c value is k c ≡ 2.6 (dotted blue curve), k c ≡ 2.3 (dashed green curve), and k c ≡ 2.2 (solid red curve); (b) so, the k c value decreases with the increase of κ and this result is in good agreement with the result of Ahmed et al's work.…”

“…The normalized governing equations to study the DAWs can be written as: where n d is the adiabatic dust grains number density normalized by its equilibrium value n d 0 ; u d is the dust fluid speed normalized by the DA wave speed C d = ( Z d k B T i / m d ) 1/2 (with T i being the ion temperature, m d being the dust grain mass, and k B being the Boltzmann constant); ϕ is the electrostatic wave potential normalized by k B T i / e (with e being the magnitude of single electron charge); the time and space variables are normalized by and λ Dd = ( k B T i /4 πZ d n d 0 e 2 ) 1/2 , respectively; p d = p d 0 ( N d / n d 0 ) γ (with p d 0 being the equilibrium adiabatic pressure of the dust, and γ = ( N + 2)/ N , where N is the degree of freedom and for one‐dimensional case, N = 1 then γ = 3); p d 0 = n d 0 k B T d (with T d being the temperatures of the adiabatic dust grains); and other plasma parameters are considered as σ 1 = 3 T d / Z d T i , σ 2 = n p 0 / Z d n d 0 , and σ 3 = Z i n i 0 / Z d n d 0 . The expression for the number density of electrons, positrons, and ions following the κ ‐distribution can be expressed, respectively, as …”

“…A number of authors have investigated the modulational instability (MI) of the carrier waves by employing the NLSE. [10][11][12][13] Chowdhury et al [10] examined the existence of the bright and dark envelope solitons in a quantum plasma medium, and observed that the thickness of the bright and dark envelope solitons is crucially affected by the variation of the plasma parameters while the height of envelope solitons remains constant. Ahmed et al [11] investigated the MI of the ion-acoustic waves in the presence of -distributed electrons and positrons, and found that the critical wave number (k c ) decreases with increasing the value of .…”

Dust-acoustic rogue waves in non-thermal plasmas

“…The point, at which the transition of P/Q curve intersect with k-axis, is known as threshold or critical wave number k (= k c ) [18,19,20,21,22,23,24,25]. The governing equation for highly energetic DARWs in the modulationally unstable parametric regime (P/Q > 0) can be written as [26,27,28,29,30]…”

Dust-acoustic rogue waves in an electron depleted plasma

“…and n −0 > n +0 for our numerical analysis. Now, the expression for positive ion number density obeying κ-distribution is given by [21]…”