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We consider quasi-one-dimensional Bose-Einstein condensates and study the properties of matter-wave bright solitons within the framework information theoretic approach. In the limit of negligible trapping effect, we calculate Shannon entropy, Fisher information, and Renyi entropy for different mean-field interactions, and study the interplay between group velocity dispersion and nonlinear atomic interaction. We see that information theoretic approach can clearly reveal localization and delocalization properties of matter-wave density distribution. In all the cases, entropic uncertainties are found to be satisfied. Key words: Bose-Einstein condensate, matter-wave solitons, Shannon entropy, Fisher information, Renyi entropy, 1. Introduction Bose-Einstein condensation (BEC) is a widely studied research topic among physicists and applied mathematicians. Its first experimental realization in 1995 using the vapour of rubidium [1] and sodium [...]

Using the solution generating technique.s of Das and Chaudhuri (Pramana J. Phys. 40, 277 (1993); Pramana J. Phys. 58, 449 (2002)), static magnetovac solutions of Einstein-Maxwell equations in general relativity are constructed from the stationary gravitational soliton solutions of Einstein's field equations corresponding to a Kerr object. The techniques followed in the present paper have not been much used in the literature so far although the results are obtained in a straightforward way. The stationary gravitational two-soliton solutions of Einstein's field equations for a Kerr object are generated using the soliton technique of Belinskii and Zakharov (Sov. Phys. JETP 48, 985 (1978); Sov. Phys. JETP 50, 1 (1979)). In the next step, following the procedure of Das and Chaudhuri, mentioned above, static magnetovac solutions of Einstein-Maxwell field equations corresponding to the generated stationary two-soliton solutions of the Kerr object are constructed. The solutions are found to be well behaved at spatial infinity and contain monopole, dipole, and other higher mass multipoles. The mass and the dipole moment of the source are evaluated. It is shown that by redefining some constants appearing in the solutions, Bonnor's (Z. Phys. 190, 444 (1966)) magnetic dipole solutions are faithfully reproduced. Key words: general relativity, exact solutions, magnetostatic solutions, Einstein-Maxwell field, two-soliton solution Utilisant la technique de generation de solution de Das et Chauduri (Pramana J. Phys. 40, 277 (1993); Pramana J. Phys. 58, 449 (2002)), des solutions statiques magnetovac des equations d'Einstein-Maxwell en relativite generale sont construites a partir des solutions solitoniques stationnaires des equations de champ d'Einstein correspondant a un objet de Kerr. Les techniques utilisees ici n'ont pas ete beaucoup utilisees dans la litterature jusqu'a present, bien que les resultats soient obtenus de maniere directe. Les solutions gravitationnelles stationnaires a deux solitons des equations d'Einstein pour un objet de Kerr sont generees en utilisant la technique de Belinski et Zakharov (Sov. Phys. JETP 48, 985 (1978); Sov. Phys. JETP 50, 1 (1979)). Dans l'etape suivante, suivant la procedure de Das et Chauduri mentionnee plus haut, sont obtenues les solutions statiques magnetovac des equations de champ d'Einstein-Maxwell correspondant aux solutions statiques a deux solitons generees pour un objet de Kerr. Nous trouvons que les solutions ont un bon comportement a l'infini spatial et contiennent monopole, dipole et multipoles de masse d'ordre plus eleve. La masse et le moment dipolaire de la source sont evalues. Nous montrons que, en redefinissant certaines constantes apparaissant dans la solution, les solutions dipolaires de Bonnor (Z. Phys. 190, 444 (1966)) sont pleinement reproduites. [Traduit par la Redaction] Mots-cles : relativite generale, solutions exactes, solutions magnetostatiques, champ de Einstein-Maxwell, solution a deux solitons, 1. Introduction In this paper, we construct static magnetic dipole solutions of Einstein-Maxwell (EM) field equations from the stationary gravitational two-soliton solutions of a Kerr object [1]. To generate magnetostatic [...]

In this study, we discuss string cosmology with solitonic NS-NS matter, which arises when dilaton coupled p-brane gas dominates the universe and is subject to a fractional action motivated from viscosity dissipative effects occurring in the universe. Exact solutions are found from the stationary conditions of the fractional action. It was observed that the universe is non-singular, undergoing accelerated expansion in time and may not be dominated by dark energy because it is strongly affected by dissipations through the fractional parameter [alpha]. The numerical ranges of [alpha] were obtained using H(z) at the 1[sigma] level for two independent cases: a vacuum energy dominated energy and a non-dominant vacuum energy universe. Our results are in agreement with astronomical observational limits and support both string cosmology and the fractional action cosmology. Key words: string cosmology, dilatonic NS-NS matter, fractional action cosmology, non-singular universe. Nous examinons ici une cosmologie cordiste de matiere solitonique NS-NS (non lineaire Schrodinger), qui apparait lorsqu'un gaz, fait de p-brane couplee a un dilaton, domine l'univers et est sujet a une action fractionnaire refletant les effets de dissipation visqueuse dans l'univers. Nous trouvons des solutions exactes pour les conditions stationnaires de l'action fractionnaire. Nous observons que cet univers est sans singularite, en expansion acceleree dans le temps et pourrait ne pas etre domine par une energie sombre puisqu'il est fortement affecte par la dissipation via le parametre fractionnaire [alpha]. Les domaines numeriques de [alpha] sont determines en utilisant H(z) au niveau 1[sigma] pour deux cas independants : un univers dont l'energie est dominee par l'energie du vide et l'autre lorsqu'elle ne l'est pas. Nos resultats sont en accord avec les limites des observations astronomiques et supportent a la fois la cosmologie cordiste et la cosmologie a action fractionnaire. [Traduit par la Redaction] Mots-cles : cosmologie cordiste, matiere dilatonique NS-NS, cosmologie a action fractionnaire, univers sans singularite., Introduction One of the most promising phenomenological candidates for quantum gravity is string theory because it solves several fundamental problems in the physics of the early universe, including the singularity [...]

In this paper, Hirota's bilinear method is extended to construct multisoliton solutions of a (2+1)-dimensional variable-coefficient Toda lattice equation. As a result, new and more general one-soliton, two-soliton, and three-soliton solutions are obtained, from which the uniform formula of the N-soliton solution is derived. It is shown that Hirota's bilinear method can be used for constructing multisoliton solutions of some other nonlinear differential-difference equations with variable coefficients. PACS Nos.: 05.45.Yv, 02.50.Fz, 04.20.Jb. Nous presentons ici une extension de la methode bilineaire de Hirota pour obtenir les solutions de l'equation sur reseau de Toda en (2+1) dimensions, avec des coefficients variables. Comme resultat, nous trouvons des solutions nouvelles et plus generales a un soliton, deux solitons et trois solitons, desquelles nous tirons la solution uniforme a N solitons. Nous montrons que la methode bilineaire de Hirota peut etre utilisee pour construire des solutions multi-solitoniques d'autres equations non lineaires differentielles et aux differences (finies) avec des coefficients variables. [Traduit par la Redaction], 1. Introduction Since 1834 when the soliton phenomenon was first observed by J.S. Russell, many exact solutions of nonlinear partial differential equations (PDEs) have been obtained. Most notably, the Korteweg--de [...]

Head-on collisions of magnetoacoustic solitary waves (MASWs) are studied in magnetized pair ion-electron plasma. The extended Poincare-Lighthill-Kuo perturbation method is used to derive the Korteweg--de Vries equations for MASWs in this three-component plasma. The effects of the magnetic field intensity [B.sub.0], the ratio of negative ions to positive ions number density S, and the plasma number density on the phase shift are investigated. It is found that these parameters can significantly influence the phase shifts of colliding MASWs. The present investigation should be useful for understanding the propagation and interaction between two MASWs that may occur in pair ion plasmas with electron impurities. PACS Nos.: 52.25.Xz, 52.35.Sb, 52.35.Mw. Nous etudions les collisions frontales d'ondes solitaires magneto-acoustiques (MASW) dans un plasma ion-electron pair magnetise. Nous utilisons la methode de perturbations de Poincare-Lighthill-Kuo pour obtenir les equations de Korteweg- -de Vries (KdV) pour des MASW dans ce plasma a trois composantes. Nous analysons les effets sur le dephasage dus a la densite de champ magnetique [B.sub.0], au rapport S de la densite d'ions negatifs sur les ions positifs et a la densite du plasma. La reponse est que ces parametres peuvent affecter significativement le dephasage dans des collisions de MASW. Cette etude devrait etre utile pour mieux comprendre la propagation et l'interaction entre deux MASW qui peuvent apparaitre dans un plasma ionique avec des impuretes electroniques. [Traduit par la Redaction], 1. Introduction In recent years, pair ion (PI) plasmas consisting of only positive and negative ions of equal mass have received considerable attention. PI plasmas represent a new state of [...]

One of the key challenges for future electronic memory and logic devices is finding viable ways of moving from today's two-dimensional structures, which hold data in an x-y mesh of [...]

A metal film perforated by a regular array of subwavelength holes shows unexpectedly large transmission at particular wavelengths, a phenomenon known as the extraordinary optical transmission (EOT) of metal hole arrays (1). EOT was first attributed to surface plasmon polaritons, stimulating a renewed interest in plasmonics (2-4) and metallic surfaces with subwavelength features (5-7). Experiments soon revealed that the field diffracted at a hole or slit is not a surface plasmon polariton mode alone (8). Further theoretical analysis (9) predicted that the extra contribution, from quasi-cylindrical waves (10-13), also affects EOT. Here we report the experimental demonstration of the relative importance of surface plasmon polaritons and quasi-cylindrical waves in EOT by considering hole arrays of different hole densities. From the measured transmission spectra, we determine microscopic scattering parameters which allow us to show that quasi-cylindrical waves affect EOT only for high densities, when the hole spacing is roughly one wavelength. Apart from providing a deeper understanding of EOT, the determination of microscopic scattering parameters from the measurement of macroscopic optical properties paves the way to novel design strategies., Understanding EOT quantitatively has been one of the main challenges in plasmonics in the past decade (see ref. 7 for a review). An important contribution to EOT may be the [...]

A sine-Gordon soliton star model with a mix of dark energy and Fermi matter is studied in the two-dimensional Brans-Dicke gravity model. The phase structure is analysed for a strong-coupling Thirring model. Subsequently, a soliton star model with cool Fermi matter coupling is constructed. We found that the soliton state and the mass of a star can change the density and pressure of matter at certain temperatures. Moreover, the stability of dark energy in the center of a star is proved when the coupling coefficient of the scalar field and Fermi matter satisfies some constraint conditions. PACS Nos: 03.05.Kk, 04.40.Dg, 97.60.-s Nous etudions un modele sine-Gordon d'une etoile soliton avec un melange d'energie sombre et de matiere fermionique dans un modele de la gravite de Brans-Dicke en deux dimensions. Nous analysons la structure de phase dans un modele de Thirring avec couplage fort. Ensuite, nous construisons un modele d'etoile soliton avec couplage de matiere fermionique froide. Nous trouvons que l'etat soliton et la masse de l'etoile peuvent changer la densite et la pression a certaines temperatures. De plus, nous demontrons la stabilite de l'energie sombre au centre de l'etoile lorsque le coefficient de couplage du champ scalaire et de la matiere fermionique satisfait certaines conditions. [Traduit par la Redaction], 1. Introduction In 1998, two teams studying distant Type I supernovae [1, 2] independently discovered the accelerated expansion of the universe. Other observations, of cosmic microware background radiation, large-scale structure, [...]

Two-dimensional evolution equations are derived as applied to flows in the near-wall jet and the Blasius boundary layer on a flat plate on which a mechanism of inviscid--inviscid infraction controls the development of large-sized short-scaled disturbances. The first one is an extension of the Korteweg--de Vries equation. As distinct from the shallow-water wave motion underlying the Kadomtsev--Petviashvili equation, the fluid parameters are not assumed to depend only weakly on the direction transversal to the oncoming stream. The second dynamical system provides a two-dimensional analog of the Benjamin--Davis--Acrivos equation. Simple line-soliton solutions are presented in both cases. A generalized Hirota function allows a pair of crossed solitons to be obtained at some distance from a solid surface in the near-wall jet. An oblique periodic nonlinear wave train pointed out for the Blasius boundary layer comes in place of the Tollmien--Schlichting waves when their amplitude attains sufficiently large values. DOI: 10.2514/1.40761

The theory of linear dispersive equations predicts that waves should spread out and disperse over time. However, it is a remarkable phenomenon, observed both in theory and practice, that once nonlinear effects are taken into account, solitary wave or soliton solutions can be created, which can be stable enough to persist indefinitely. The construction of such solutions can be relatively straightforward, but the fact that they are stable requires some significant amounts of analysis to establish, in part due to symmetries in the equation (such as translation invariance) which create degeneracy in the stability analysis. The theory is particularly difficult in the critical case in which the nonlinearity is at exactly the right power to potentially allow for a self-similar blowup. In this article we survey some of the highlights of this theory, from the more classical orbital stability analysis of Weinstein and Grillakis-Shatah-Strauss, to the more recent asymptotic stability and blowup analysis of Martel-Merle and Merle-Raphael, as well as current developments in using this theory to rigorously demonstrate controlled blowup for several key equations.

On the basis of appropriate modified Korteweg-deVries (mKdV) equation derived for three cases of [n.sub.n0] < [n.sub.e0], [n.sub.n0] = [n.sub.e0], and [n.sub.n0] > [n.sub.e0] together with [n.sub.n0] ([n.sub.e0]) as the density of negative ions (electrons), we observe that compressive and rarefactive mKdV solitons propagate in an inhomogeneons magnetized plasma having negative ions at their critical density. Two types of modes (fast and slow) separately evolve as the compressive and rarefactive solitons. However, only the solitons corresponding to the fast mode get reflected, if the obliqueness of the magnetic field lies under certain critical angle [[psi].sub.CR] which gets larger under higher thermal motions of the ions and shows stronger dependence on it when less number of negative ions are present in the plasma. There is a possibility of the change of polarities after the reflection of the solitons. The solitons suffer stronger reflection under the effect of larger ion thermal motions and smaller obliqueness of the magnetic field. The compressive solitons are found to downshift, whereas the rarefactive solitons are upshifted after the reflection, and these shifts get higher for the increasing concentration of the negative ions and lower obliqueness of the magnetic field. The compressive (rarefactive) solitons shift less (more) in the plasmas with ions of higher thermal energy; however, the upshift shows opposite behavior for the case of [n.sub.n0] > [n.sub.e0.] Index Terms--Compressive and rarefactive solitons, critical density, negative ions, soliton reflection, thermal and gyratory motions of ions.

The concept of soliton dispersion management pertaining to the effect of varying dispersion with external harmonic oscillator potential for chirped solitons is discussed. Results suggest the successful suppression of the interaction forces between the two dispersion managed solitons by properly choosing the soliton parameters.

The nonlinear dynamics of a passive mode-locked fiber laser containing a long period fiber grating are evaluated. Results suggest the existence of passive mode-locking and autosoliton generation in the cavity of the laser.

Analyzing a free boundary problem for harmonic functions in an infinite planar domain, we prove that in a solitary water wave each particle is transported in the wave direction but slower than the wave speed. As the solitary wave propagates, all particles located ahead of the wave crest are lifted, while those behind it experience a downward motion, with the particle trajectory having asymptotically the same height above the flat bed.

The Pariser-Parr-Pople- density matrix renormalization group (PPP-DMRG) method is applied to semiempirical quantum chemical study on neutral and positively charged trans-PA oligomers with up to 101 carbon atoms. The comparison of the geometrical and electronic distortions induced by defects with the theoretical work shows that sufficient account of the electron correlation is necessary for describing the systems.

The design and analysis of an Nth-order optical integrator using the digital filter technique is presented. The optical integrator is synthesized using planar-wavegnide technology. It is shown that a first-order optical integrator can be used as an optical dark-soliton detector by converting an optical dark-soliton pulse into an optical bell-shaped pulse for ease of detection. The optical integrators can generate an optical step function, staircase function, and paraboliclike functions from input optical Gaussian pulses. The optical integrators may be potentially used as basic building blocks of all-optical signal processing systems because the time integrals of signals may sometimes be required for further use or analysis. Furthermore, an optical integrator may be used for the shaping of optical pulses or in an optical feedback control system. OCIS codes: 070.0070, 130.0130, 230.0230.

The evolution of a gust front to bore to solitary wave transition, and comprehensive information on the evolving nocturnal boundary layer (NBL) associated with this change, are described with analysis of radar and profiler measurements. The observations were obtained on 21 June 2002 in the Oklahoma panhandle during the International [H.sub.2]O Project. The evolution of this system, from a strong bore (initiated by a vigorous gust front) to a solitary wave, was observed over a 4-h period with Doppler radar and surface measurements. Detailed information on the mature bore structure was obtained by a cluster of profiling instruments including two boundary layer wind profilers, a lidar ceilometer, and a microwave profiling radiometer. A strong bore was initiated by an extensive gust front that perturbed an incipient NBL whose development (prior to sunset) was enhanced by shading from the parent mesoscale convective system. At the time of bore formation, the NBL was about 300 m deep and exhibited a surface temperature about 4 K less than the afternoon maximum. Initially, the bore assumed kinematic properties similar to those of a gust front. As the NBL stabilized, the bore matured and exhibited undular formations over 30-60-km segments along the bore axis. A 30-km-wide cloud field accompanied the mature bore system within three hours of its formation. System-relative airflow within the cloud field was front-to-rear and exhibited a primary hydraulic jump updraft (4-5 m [s.sup.-1] magnitude) within the bore core. The bore core exhibited a low, smooth cloud base, a cloud depth of 2.5 km, nearly adiabatic liquid water content, and pronounced turbulence. The maximum parcel displacements within the bore were about 2 km (sufficient for marginal convective initiation), and the net parcel displacement from before to after bore passage was 0.64).9 km.

Electronic structure calculations on a conjugated polymer chain by Hartree-Fock and density functional theory show a sequence of self-localized states, which stand in contrast to the single self-localized soliton state described by the Su-Schrieffer-Heeger model Hamiltonian. An extended Hubbard model, which treats electron-electron interactions up to second neighbors, is constructed to demonstrate that the additional states arise from a strong band-bending effect due to the presence of localized electric fields of charged solitons. We suggest the optical response of these electronic states may be associated with the near-edge oscillations observed in photo-induced absorption spectra. Our calculations indicate further that in the presence of counterions, the additional localized states continue to exist. Implications regarding soliton mobility and high-resolution ion sensing are briefly discussed. conducting polymer | self localization | soliton

A distortion-free digital image is transmitted through parallel propagation of white-light photovoltaic dark solitons. The waveguide channels induced by white-light dark solitons can guide both the laser beam and the white-light beam well. We determine experimentally the critical separations of the dark solitons in the directions parallel and perpendicular to the crystalline c axis for the given crystal thickness. OCIS codes: 230.7370, 210.4680, 190.5330.

The phenomenon of modulation instability (MI) and its associated gain spectra in Bragg grating (BG) structure for generating the ultrashort pulses is investigated. MI for the BG structure in fibers under the influence of non-Kerr nonlinearity is analyzed.

A numerical and experimental study of the formation dynamics of soliton-like optical beams in biased nematic-liquid-crystal planar cells is reported. The soliton-induced waveguide is observed in transmission by use of a second light source and crossed polarizers.

Nonlinear pulse propagation through a fiber Bragg grating structure in which pulse dynamics are determined by nonlinear-coupled mode (NLCM) equations is investigated and discussed.

We report the cancellation of the soliton self-frequency shift in a silica-core photonic crystal fiber with a negative dispersion slope. Numerical and experimental results show that stabilization of the soliton wavelength is accompanied by exponential amplification of the red-shifted Cherenkov radiation emitted by the soliton. The spectral recoil from the radiation acts on the soliton to compensate for the Raman frequency shift. This phenomenon may find applications in the development of a family of optical parametric amplifiers., Solitary waves, or solitons, are self-localized regions of energy or matter that occur in a large variety of fundamental processes in many natural and artificially created nonlinear systems, such as [...]

A model is described which explains the functional dependence of a Josephson fluxonic diode (JFD) forward bias I-V curve on parameters of the junction.

The properties of submicron intrinsic Joesphson junctions (IJJ), fabricated on Bi-2212 liquid phase epitaxy film are investigated and reported.

Optical transverse instabilities in quantum-dot (QD) microresonators are examined. A model for the QD suseptibility is developed that takes inhomogeneous broadening of dot emissions into account.

An overview of the state of the art in this field is presented. The basic set of evolution equations are derived, and various pw solutions and their stability behavior are analyzed.

Stable circular domain walls (droplets) and dark-ring cavity solitons are examined in models of vectorial Kerr resonators and degenerate optical parametric oscillators.

Localized states (LS) in a single-mirror feedback system that uses sodium vapor as the nonlinear medium are investigated and reported.

Pattern formation in passive systems is described, including the coupling between the modulational modes and the quasineutral homogenous zero mode. And the interaction and stability of both bright and dark localized structures (LS).

The Newton-Fourier (NF) approach from the analysis of cavity solitons is generalized to the analysis of periodic patterns deriving from a stationary modulational instability (MI) and not endowed with cylindrical symmetry.

A study is reported of transverse two-dimensional stationary and oscillating solitons in a wide-aperture laser with a saturable absorber and fast nonlinearity of both gain and absorption.

This Feature Section of the IEEE Journal of Quantum Electronics (Feb 2003) focuses on the topic of cavity solitons (CS). An overview introduction is provided, with a bibliography.

The existence and properties of spatial solitons, excited in externally driven nonlinear resonators, is described and discussed.

An overview of theoretical and experimental research involving spatial optical solitons excited in arrays of nonlinear waveguides is presented.

An overview of research involving quadratic solitons is presented.

An overview of research involving spatial optical solitons is presented.

Observations of solitons and related phenomena are described. Models are discussed.

A new model for the active modulation component of a mode-locked laser cavity is described and discussed.

The modelocking performance of an actively mode-locked inhomogeneously broadened laser in various group velocity dispersion (GVD) regions is examined. Numerical simulation and experiments are employed.

Nonlinear waveguiding effects in engineered quasi-phase-matching (QPM) geometries in periodically poled lithium niobate (PPLN) are investigated. Specifically, the existence and propagation of pure nonlinear guided modes in QPM gratings with different domain lengths in different transverse regions of the medium are examined.

Research suggests that solitons in the Bay of Biscay are produced locally via the surfacing of an internal tidal energy beam which originates from the continental shelf break, rather than traveling along the thermocline.

Research describing the propagation of solitary waves in nonlinear transmission lines is presented. In particular the effects of heterostructure barrier vactor loading are investigated.

Research is presented concerning the proposal and demonstration of a technique which can be used for the generation of dark and bright soliton trains simultaneously from continuous-wave light.

Three methods of measuring instantaneous frequency of optical pulses are presented.

The effects of noise on soliton propagation in erbium-doped fiber amplifiers were studied using a version of the split-step Fourier method.

A recirculation loop experiment was used to investigated the soliton optical phase stability versus amplified spontaneous noise.

Continuous wave magnetostatic wave signals and their effects on microwave magnetic envelope soliton pulse formation in magnetic films were studied.