Mouloud Tribeche

• Professor
• Founding member of the Algerian Academy of Sciences and Technologies. at University of Sciences and Technology Houari Boumediene

Ion acoustic waves (IAWs) are studied for degenerate trapped electron and non-degenerate ion plasma in the presence of quantizing magnetic field in the Tsallis framework. The presence of a magnetic field induces a trapping effect on degenerated electrons, which is studied using the generalized form of the Fermi–Dirac in the non-extensive framework....

The formation and the basic features of arbitrary amplitude ion-acoustic solitary waves (IASWs) in an electronegative plasma containing cold negative ion fluid, warm positive ion fluid and nonextensive electrons are theoretically investigated by using the pseudo-potential technique. The pseudo-potential is analytically and numerically analyzed and...

The modification of Debye length and electric potential due to the combined effects of nonextensive distribution of particles in an electron-ion plasma system, ratio of electron temperature to ion temperature, and external static magnetic field is theoretically examined. The expression for the modified Debye length is derived by solving Poisson's e...

In this paper, dressed solitons in dusty plasma in the presence of polarization forces acting on the dust grains are investigated. Including fourth-order nonlinearities of electric potential and integrating the resulting energy equation, an exact soliton solution is obtained for dust acoustic waves in dusty plasma. This exact solution reduces to th...

The sheath criterion is modified for a plasma consisting of two-temperature nonextensively distributed electrons and positive ions with finite temperature. Using a two-fluid model, effects of the plasma parameters, such as temperature and density of positive ions and temperature ratio and degree of nonextensivity of both electron species on the all...

Through a kinetic approach, in which temperature fluctuations are taken into account, we obtain generalized fractional statistics interpolating between Fermi-Dirac and Bose-Einstein statistics. The latter correspond to the superstatistical analogues of the Polychronakos and Haldane-Wu statistics. The virial coefficients corresponding to these stati...

Effects of presence of ions on the existence and structure of arbitrary amplitude ion-acoustic solitary waves in a plasma consisting of thermal ions and two-temperature nonextensive electrons are investigated. It is shown that solitons of both polarity (compressive and rarefactive) can exist in such a plasma, depending on the range of the plasma pa...

The problem of arbitrary amplitude ion- acoustic solitary waves (IASWs), which accompany electronegative plasmas having positive ions, negative ions, and nonextensive electrons is addressed. The energy integral equation with a new Sagdeev potential is analyzed to examine the existence regions of the IASWs. Different types of electronegative plasmas...

Many complex systems exhibiting fluctuations can be described by decomposing their dynamics at different scales. Their statistical properties are then given by a mixture of statistics, i.e., superstatistics. In this paper, we study quantum entanglement in a system, obeying a superstatitical model. Such an approach is expected to be a suitable appro...

We examine the excitation of breather structures in a degenerate relativistic plasma consisting of nonextensive electrons and cold ions. For this purpose, the multiple-time scale perturbation technique is used to obtain a nonlinear Schrodinger equation (NLSE). We then consider different localized solutions regarding analytical breather solutions of...

In this paper, we consider entanglement in a system out of equilibrium, adopting the viewpoint given by the formalism of superstatistics. Such an approach yields a good effective description for a system in a slowly fuctuating environment, within a weak interaction between the system and the environment. For this purpose, we introduce a new version...

A hydrodynamic model is employed to investigate the linear and non-linear propagation of Electrostatic Positron Acoustic Waves (EPAWs) in a 4-component relativistic-degenerate Electron-Positron-Ion (EPI) plasma. The plasma constituents are cold positrons, hot relativistic-degenerate electrons and positrons, and cold static ions in the background. T...

The problem of small amplitude dust- acoustic double-layers in a polarized dusty plasma is addressed . Our results show that in such a plasma double-layers structures, the amplitude and nature of which depend sensitively on the plasma parameters, can exist. In particular, it may be noted that as the polarization parameter R increases, the domain of...

We investigate theoretically the effects of the nonthermal polarization force acting on dust grains in an inhomogeneous plasma containing Maxwellian electrons, nonthermal ions, and fluid negatively charged dust grains. The effects of this polarization force are significantly modified due to the presence of the nonthermal ions. In particular, an inc...

The thermodynamic properties of the blackbody radiation are revisited, for the first time, within the theoretical framework of the κ-statistics introduced by Kaniadakis. Using the κ-counterpart of the Bose-Einstein distribution, generalized expressions for the free energy, the entropy, the specific heat, and the pressure are obtained. All quantitie...

A theoretical investigation is made to study envelope excitations and rogue wave structures of the newly predicted positron- acoustic waves (PAWs) in a plasma with nonextensive electrons and nonextensive hot positrons. The reductive perturbation technique (RPT) is used to derive a nonlinear Schrödinger equation- like (NLSE) which governs the modula...

The polarization force acting on dust particles in a dusty plasma is revisited within the theoretical framework of the Tsallis statistical mechanics. The generalized nonextensive polarization force expression is derived. As application, the modifications arising in the propagation of dust- acoustic solitary waves, and dust sheath formation are anal...

The effects of the polarization force on the self-similar expansion into vacuum of an unmagnetized, collisionless dusty plasma are addressed. It is found that the polarization force may drastically influence the general trends of the self-similar expansion. It is noticed that when the polarization force dominates over the electrical one, the self-s...

Dynamique non lin eaire des plasmas Cours et exercices, Master 2 Physique Théorique, parcours: Théorie et Modélisation en Physique des Plasmas

Dynamique non lin eaire des plasmas Cours et Exercices, Master 2 Physique Théorique, parcours: Théorie et Modélisation en Physique des Plasmas

Ion- acoustic rogue waves are investigated in a two-component magnetized solar wind plasma, composed of positively charged fluid ions, as well as nonextensive electrons. Typical solar wind plasmas parameters are used. It is shown that the wave number domain for the onset of ion- acoustic modulational instability enlarges as the electrons evolve tow...

The problem of electron- acoustic (EA) rogue waves in a plasma consisting of fluid cold electrons, nonthermal nonextensive electrons and stationary ions, is addressed. A standard multiple scale method has been carried out to derive a nonlinear Schrödinger-like equation. The coefficients of dispersion and nonlinearity depend on the nonextensive and...

The problem of nonlinear quantum positron- acoustic waves (QPAW's) is addressed in a dense astrophysical plasma. The latter is composed of four different species. Using the quantum hydrodynamic model (QHD) model and carrying out a weakly nonlinear analysis, Korteweg- de Vries (K- dV) and generalized K- dV equations are derived. The influence of qua...

The problem of nonlinear quantum positron-acoustic waves (QPAW's) is addressed in a dense astrophysical plasma. The latter is composed of four different species. Using the quantum hydrodynamic model and carrying out a weakly nonlinear analysis, Korteweg-de Vries (K-dV) and generalized K-dV equations are derived. The influence of quantum effects on...

In this article we have investigated the propagating properties of coupled Kinetic Alfven-acoustic waves in a low beta plasma having superthermal electrons and positrons. Using the standard reductive perturbation method, a nonlinear Korteweg-de Vries (KdV) type equation is derived which describes the evolution of Kinetic Alfven waves. It is found t...

We rely on our proof of the non-decreasing character of quantum Kaniadakis entropy under projective measurement [Phys. Rev. E 92, 032114 (2015)], and put it into perspective with the results of Bosyk et al. [arXiv:1506.02090]. Our method, adopted for the proof that Kaniadakis entropy does not decrease under a projective measurement, is based on the...

The combined effects of an oblique magnetic field and electron trapping on dissipative dust-acoustic waves (DAWs) are examined in a varying charge electronegative dusty plasmas with application to the Halley Comet plasma (∼10⁴ km from the nucleus). A weakly nonlinear analysis is carried out to derive a modified Korteweg-de Vries-Burger- like equati...

Nonthermal particle distribution are commonly found in space plasmas, for example, planetary magnetosphere, solar and stellar coronas, solar wind. In the literature, nonthermal distributions have been characterized by Cairns, Kappa, Lorentian and Tsallis distributions. Since all these distributions have excess of energetic particles, over and above...

During active Sun, the solar flares emissions in the range of UV and X- ray penetrate down into the D-region of the ionosphere. This leads to an increasing of the ionization rate. As a consequence, the propagation of a Very Low Frequency (VLF) radio signal is then affected. In this work, we have studied the X-ray solar flares effect on the NRK tran...

Dust is an ubiquitous component of space and astrophysical environments, occurring for example in planetary rings, comets and the Earth's ionosphere [1]. Dusty plasmas are known to support a wide variety of ultra low-frequency wave modes. The most well studied of such modes are the so called dust-acoustic wave (DAW) [2] and dust ion-acoustic wave (...

The aim of the present communication is to investigate the charge variation induced nonlinear dust acoustic wave damping in a charge varying electronegative dusty plasma with nonthermal ions. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Kort...

Weakly nonlinear ion-acoustic (IA) double-layers (DLs), which accompany electronegative plasmas composed of positive ions, negative ions, and nonextensive electrons are investigated. A generalized Korteweg-de Vries equation with a cubic nonlinearity is derived using a reductive perturbation method. Different types of electronegative plasmas inspire...

The combined effects of ionization, ion loss and electron suprathermality on dust ion- acoustic solitary waves in a collisional dusty plasma are examined. Carrying out a small but finite amplitude analysis, a damped Korteweg- de Vries (dK-- dV) equation is derived. The damping term decreases with the increase of the spectral index and saturates for...

Ce polycopié se veut être une introduction à la physique statistique non- extensive. En guise d'applications, nous avons délibérément choisi de ne présenter que certains de nos résultats de recherche ayant trait à la distribution de Fermi-Dirac non-extensive. Celle-ci est une généralisation à un paramètre de la distribution bien connue de Fermi-Dir...

Ce chapitre de cours constitue la première mouture d'une introduction aux oscillations non linéaires dans les plasmas poussiéreux électronégatifs. Il constitue une partie du cours "Physique des Plasmas Complexes (PPC)" que nous dispensons aux étudiants de Master 2 Physique Théorique, parcours: Théorie et Modélisation en Physique des Plasmas. De plu...

Weak ion-acoustic solitary waves (IASWs) in an unmagnetized quantum plasmas having two- fluid ions and fluid electrons are considered. Using the one-dimensional quantum hydrodynamics model and then the reductive perturbation technique, a generalized form of nonlinear quantum Korteweg–de Vries (KdV) equation governing the dynamics of weak ion acoust...

Ce polycopié constitue la première mouture d'une introduction à la dynamique faiblement non linéaire d'un plasma qui (sommairement) se définit comme étant un gaz électrifié dont les atomes sont dissociés en ions à charge positive et électrons à charge négative. Il constitue une partie du cours "Dynamique Non Linéaire des Plasmas (DNLP)" que nous di...

The role the polarization force acting on dust particles may play on the energy carried by the dust- acoustic (DA) soliton is examined. This force is due to the deformation of the Debye sheath around the dust particulates in the background of non-uniform plasmas. The energy carried by the DA solitons is derived. This energy decreases with an increa...

The electron trapping in a weakly nondegenerate plasma is reformulated and re- examined by incorporating the nonextensive entropy prescription. Using the q-deformed Fermi--Dirac distribution function including the quantum as well as the nonextensive statistical effects, we derive a new generalized electron density with a new contribution proportion...

We examine the effects of the κ-deformed Kaniadakis electron distribution on small amplitude electron-acoustic double-layers (EADLs). The deformed mean kinetic energy of the electrons is computed to narrow the values of the deformation parameter κ that underpins Kaniadakis entropy. It is shown that the Kaniadakis entropy effect is to higher the cri...

The combined effects of ionization, ion loss, and electron suprathermality on dust ion-acoustic solitary waves in a collisional dusty plasma are examined. Carrying out a small but finite amplitude analysis, a damped Korteweg-de Vries (dK–dV) equation is derived. The damping term decreases with the increase of the spectral index and saturates for Ma...

A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries (mKd...

A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equ...

The Hamiltonian guiding center drift orbit formalism is used which permits the efficient calculation of ionic trajectories perturbed by a fast-wave in a stochastic magnetic …eld. The magnetic …field is assumed to be a small perturbation from a zero-order “"equilibrium”" fi…eld possessing magnetic surfaces, toroidal symmetry and modeled analytically...

A theoretical investigation is carried out to study the existence, formation and basic properties of ion acoustic (IA) double layers (DLs) in a magnetized bi-ion plasma consisting of warm/cold ions and Boltzmann distributed electrons. Based on the reductive perturbation technique, an extended Korteweg de-Vries (KdV) equation is derived. The propaga...

The implications of the non- Maxwellian electron distributions (nonthermal/or suprathermal/ or nonextensive distributions) are examined on the dust- ion acoustic (DIA) rogue/freak waves in a dusty warm plasma. Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation (NLSE). The latter...

La statistique non extensive de Tsallis, généralisation à un seul paramètre de la statistique de Boltzmann- Gibbs, a récemment connu un grand regain d’intérêt. On se propose dans ce travail de présenter un état de l’art de cette nouvelle statistique en insistant sur son contexte, ses fondements, ses domaines d’application et surtout sur la nécessit...

The polarization force-induced changes in the dust-acoustic waves (DAWs) modulational instability (MI) are examined. Using the reductive perturbation method, the nonlinear Schrödinger equation that governs the MI of the DAWs is obtained. It is found that the effect of the polarization term R is to narrow the wave number domain for the onset of inst...

The modifications arising in the dusty plasma sheath structure due to the presence of polarization forces acting on the dust grains are investigated. The corresponding appropriate Bohm criterion for sheath formation is obtained. It is found that the critical Mach number beyond which the dusty plasma electrostatic sheath sets in, decreases whenever...

The problem of the head-on collision of two ion- acoustic solitary waves (IASWs) is addressed in electronegative plasmas with a nonextensive electron velocity distribution. Our plasma model is inspired from the experimental studies of Ichiki et al. [Phys. Plasmas 8, 4275 (2001)]. Using the extended Poincare-Lighthill-Kuo (PLK) perturbation method,...

It is well-known that the von Neumann entropy of a quantum state does not decrease with a projective measurement. This property holds for Tsallis and Rényi entropies as well. In this brief report, we show that the recently introduced quantum version of the Kaniadakis entropy preserves this property.

Modulation instability of ion-acoustic waves (IAWs) is investigated in a collisionless unmagnetized one dimensional plasma, containing positive ions and electrons following the mixed nonextensive nonthermal distribution [Tribeche et al., Phys. Rev. E 85, 037401 (2012)]. Using the reductive perturbation technique, a nonlinear Schrödinger equation wh...

A first use of the κ- deformed Kaniadakis distribution in the context of nonlinear plasma waves is outlined. The deformed mean kinetic energy of the electrons is computed to narrow the values of the deformation parameter κ that underpins Kaniadakis entropy. As application, we examine the influence of κ on small amplitude ion- acoustic double- layer...

Editorial Le Comité Editorial a l’immense plaisir d’annoncer que le numéro 1 du volume 2 de la Revue Algérienne de Physique (www.usthb.dz/RAP) est maintenant finalisé. Comportant dix articles, ce numéro est mis, en libre accès, à la disposition de la communauté universitaire. Les dix articles, à l’instar de tout article soumis à la RAP, ont fait l’...

Ion-acoustic rogue waves (IARW) are addressed in a two-component plasma composed of positively charged fluid ions, as well as electrons obeying the q-nonextensive distribution function in the presence of the external magnetic field B with application to the solar wind. The basic set of hydrodynamic equations is presented, and the nonlinear Schrödin...

Ion-acoustic rogue waves (IARW) are addressed in a two-component plasma composed of positively charged fluid ions, as well as electrons obeying the q-nonextensive distribution function in the presence of the external magnetic field B with application to the solar wind. The basic set of hydrodynamic equations is presented, and the nonlinear Schrödin...

Study of linear or nonlinear wave phenomena in electron-positron (e-p) plasmas attracted much attention during the last decade due to their frequent occurrence in active galactic nuclei, pulsar magnetosphere and in solar atmosphere. The electron-positron (e-p) plasmas are also believed to play an important role in understanding the early universe....

The concept of ion nonthermality is generalized within the theoretical framework of the Tsallis thermostatistics. In this connection, a physically meaningful ion distribution function is outlined. In this communication, we have investigated solitary dust acoustic wave propagation in a charge varying dusty plasma in the presence of ion nonthermality...

The effects of electron nonextensivity for a given nonthermality state, on Debye shielding and electrostatic sheath formation are examined. A physically meaningful Cairns-Tsallis distribution is outlined and a generalized expression for the Debye screening length λ_{D}^{q,α} is obtained. It is shown that an increase of the entropic index q causes λ...

A first use of the Kaniadakis entropy in the context of quantum information is presented. We first show that (as all smooth and concave trace-form entropies) it exhibits some properties allowing it to be a possible candidate for a generalized quantum information theory. We then use it to determine the degree of entanglement. The influence of the pa...

Dans ce travail, l'onde acoustique poussiéreuse dans un plasma poussiéreux magnétisé à charge variable a été étudiée. En incorporant les effets non thermiques des ions, dont la distribution des vitesses est modélisée par une fonction de distribution non thermique de Cairns. Le courant de charge non thermique des ions a été établi dans le cadre de l...

weak ion-acoustic (IA) solitary wave propagation is investigated in the presence of electron trapping and background nonextensivity. A physically meaningful distribution is outlined and a schamel-like equation is derived. The role a background electron nonextensivity may play on the energy carried by the IA soliton is then examined. It is found tha...

L’observation des structures d’ondes solitaires avec une déplétion de la densité, effectuée par le satellite Freja [1] a incité Cairns et ses collaborateurs à étudier les effets de la présence des électrons nonthermiques dans le milieu plasma, sur les propriétés des ondes acoustiques ioniques (IAWs) [2]. À cet effet, la fonction de distribution des...

The electrons exchange–correlation influence on the energy carried by the quantum ion-acoustic soliton (QIAS) is succinctly discussed. Starting from the one-dimensional quantum hydrodynamic model (in which the term of exchange–correlation for electrons is included), a deformed Korteweg–de Vries-like equation is derived. It is found that the QIAS en...

Les plasmas sont des gaz ionisés que l’on rencontre aussi bien à l’état naturel que dans l’industrie. En plus des atomes, molécules, ions et électrons, ils contiennent fréquemment des objets solides (poussières) dont la taille peut varier du nanomètre au centimètre. Ces plasmas, que l’on nomme alors plasmas poussiéreux, sont très répandus en astrop...

Notre présente étude consiste à revisiter, au moyen d'une approche analytique et numérique, les structures acoustiques poussiéreuses non linéaires associées à un plasma complexe dans le contexte du formalisme non extensif. Pour ce faire, nous avons utilisé les équations de base du modèle fluide et certains résultats de la théorie cinétique. Nous no...

Ce travail consiste en une étude du transfert thermique dans un revêtement multicouche réalisé par projection plasma et destiné à la protection des surfaces exposées à un environnement agressif tel que la protection contre l’oxydation à haute température. Il s’agit de simuler l’effet du flux de chaleur du plasma imposé lors de la projection sur la...

We propose to put the well-known nonthermal and suprathermal empirical distributions, used in plasma physics, onto a more rigorous foundation. Their use is frequently criticized because of a lack of formal derivation and physical explanation. A connection between these non-Maxwellian distributions and the Beck-Cohen superstatistics is suggested. Th...

La Revue Algérienne de Physique (RAP : ISSN : 1112-8224) est un Journal Scientifique dédié à la Physique et ses Applications. Elle se fixe comme objectifs l’amélioration, la valorisation et une meilleure dissémination des travaux de recherche en Physique des communautés académique et industrielle. Edité deux fois par année par l’Association Algérie...

We propose to put the well-known nonthermal and suprathermal empirical distributions, used in plasma physics, onto a more rigorous foundation. Their use is frequently criticized because of a lack of formal derivation and physical explanation. A connection between these non-Maxwellian distributions and the Beck-Cohen superstatistics is suggested. Th...

We examine the effect of the electron exchange-correlation on weak and arbitrary amplitude quantum dust ion-acoustic (QDIA) solitons. The reduced quantum hydrodynamic (QHD) model is used. Carrying out a fully nonlinear analysis, it is found that the effect of the exchange-correlation on the main quantities for solitary-wave propagation can be quite...

The propagation and interaction between ion acoustic multi-solitons in an unmagnetized multicomponent plasma consisting of fluid hot ions, positrons and both hot and cold electrons, are investigated by employing the extended Poincare-Lighthill-Kuo (PLK) method. Two different Kortewege-de Vries (K- dV) equations are derived. The Hirota's method is a...

Nonlinear quantum positron-acoustic (QPA) waves are investigated for the first time, within the theoretical framework of the quantum hydrodynamic model. In the small but finite amplitude limit, both deformed Korteweg-de Vries and generalized Korteweg-de Vries equations governing, respectively, the dynamics of QPA solitary waves and double-layers ar...

The charge variation induced nonlinear dust-acoustic wave damping in a charge varying dusty plasma with nonextensive ions is considered. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Korteweg-de Vries (dK-dV) equation the coefficients of whic...

The electrons exchange-correlation influence on the energy carried by the quantum ion- acoustic soliton (QIAS) is succinctly discussed. Starting from the one-dimensional quantum hydrodynamic model (in which the term of exchange-correlation for electrons is included), a deformed Korteweg-de Vries- like equation is derived. It is found that the QIAS...

Using the extended Poincaré-Lighthill-Kuo (EPLK) method, the interaction between two ion acoustic solitary waves (IASWs) in a multicomponent magnetized plasma (including Tsallis nonextensive electrons) has been theoretically investigated. The analytical phase shifts of the two solitary waves after interaction are estimated. The proposed model leads...

X-ray and UV radiations emitted from the sun during solar flares, may cause enhancement of the ionization in the lower ionosphere. To study the effect of solar flares and their occurrence in the daytime on the D layer of the ionosphere (60-90 Km), we used Very Low Frequency (VLF) data of the NRK-ALG GCP (NRK: 63.85 N, 22.45 W, 37.5 KHz; Algiers: 36...

The role electron nonextensivity may play on the energy carried by the ion-acoustic (IA) solitons is examined. A Korteweg–de Vries (K–dV) equation is derived. It is found that an increase of the nonextensive parameter qq leads to a decrease of the soliton amplitude and width. The soliton energy is depleted as qq increases.

The 18O(p,α)15N reaction influences the isotopes production such as 19F, 18O, and 15N which can be used to test the models of stellar evolution. 19F is synthesized in both asymptotic giant branch (AGB) and metal-rich Wolf-Rayet (WR) stars. Using R-matrix theory we allow new values of resonances parameters in 19F. We show that the most important con...

Over the last few years, a great deal of attention has been paid to nonextensive statistic mechanics based on the deviations of Boltzmann-Gibbs-Shannon (BGS) entropic measure. A suitable nonexten-sive generalization of the BGS entropy for statistical equilibrium was first recognized by Renyi and subsequently proposed by Tsallis [1], suitably extend...

The propagation of cylindrical and spherical electron acoustic (EA) shock waves in unmagnetized plasmas consisting of cold fluid electrons, hot electrons obeying a superthermal distribution and stationary ions, has been investigated. The standard reductive perturbation method (RPM) has been employed to derive the cylindrical/spherical Korteweg-de-V...

Weak ion acoustic (IA) solitary waves are investigated in a mixed nonextensive high energy-tail electron distribution, focusing on the influence of an interplay between nonthermality and nonextensivity on the IA soliton nature, its carried energy and associated rogue waves. The IA soliton exhibits compression or rarefaction depending on the strengt...

Alternative localized dust-ion acoustic waves are investigated in a magnetized charge varying dusty plasma with nonthermal electrons having a vortex-like velocity distribution. The correct non-Maxwellian charging currents are obtained based on the well-known orbit limited motion theory. Following the standard reductive perturbation technique, a Sch...

Blackbody radiation is reconsidered using the counterpart of the Bose-Einstein distribution in the κ statistics arising from the Kaniadakis entropy. The generalized Planck radiation law is presented and compared to the usual law, to which it reduces in the limiting case κ→0. Effective Einstein's coefficients of emission and absorption are defined i...

A study is presented for the oblique propagation of low-frequency ion-acoustic (IA) shock waves in a magnetized plasma having cold viscous ion fluid and nonextensively distributed electrons. A weakly nonlinear analysis is carried out to derive a Korteweg de-Vries-Burger like equation. Dependence of the shock wave characteristics (height, width and...

Solar flares cause additional ionization in the D layer of the ionosphere (60-90 Km), which appears as amplitude and phase perturbations on the VLF signal. In this work, we present results of the properties of the VLF signals perturbations (amplitude, phase, h’ and β) and their dependences with solar flares flux (For the period: 2007-2012). In this...

Weak ion-acoustic (IA) solitary wave propagation is investigated in the presence of electron trapping and background nonextensivity. A physically meaningful distribution is outlined and a Schamel-like equation is derived. The role a background electron nonextensivity may play on the energy carried by the IA soliton is then examined. It is found tha...

Weak dust acoustic (DA) solitary waves are investigated in a mixed nonthermal high energy-tail electron distribution, focusing on the influence of an interplay between nonthermality and superthermality on the DA soliton energy. It is shown that in a pure superthermal plasma (α=0), electron thermalization (κ→∞) leads to an increase of the energy car...

Large amplitude dust ion acoustic (DIA) solitons as well as double layers (DLs) are studied in a dusty plasma having a high-energy-tail electron distribution. The influence of electron deviation from the Maxwellian distribution and ion streaming on the existence domain of solitons is discussed in the (M, f) space using the pseudo-potential approach...

A theoretical investigation is carried out to analyse the propagation of ion acoustic (IA) waves in a magnetized bi-ion plasma having two populations of fluid ions and kappa-distributed electrons. The propagation properties of all possible modes (in the linear regime) are investigated. The nonlinear evolution of the IA solitary waves is governed by...

Using the generalized Fermi–Dirac distribution function arising from Tsallis statistical mechanics, we revisit the Sommerfeld model for metallic elements. The chemical potential, the total energy and the heat capacity are calculated. It is shown that the linearity between the heat capacity and the temperature is q-dependent, where q stands for the...