Woo-Pyo Hong

Optical solitary wave solutions for the higher order nonlinear Schrödinger equation with cubic-quintic non-Kerr terms

We find general analytical bright and dark solitary wave solutions for the higher order nonlinear Schrodinger equation with cubic-quintic terms describing the effects of ultra-short (femtosecond) optical soliton propagation in non-Kerr media. The allowed model coefficients regions for the dark and bright solitary waves are found from the existence requirement of the solutions. All the physical parameters in the solitary wave solutions are obtained as functions of the model coefficients. Explicit examples are presented.

Modulational instability of optical waves in the high dispersive cubic–quintic nonlinear Schrödinger equation

Abstract The modulational instability of an extended nonlinear Schrodinger equation with the third and fourth-order dispersion and the cubic–quintic nonlinear terms, describing the propagation of extremely short pulses, is investigated. Two types of gains by modulational instability are found to exist in both the anomalous and normal dispersion regimes under some constraints among the model coefficients. The evolutions of modulational instability in both the anomalous and normal dispersion regimes are numerically investigated and the effects of the higher-order dispersion and nonlinear terms on the evolutions are examined.

Possibility of unique detection of primordial black hole gamma-ray bursts

We describe the properties of primordial black hole (PBH) burst emission, pointing out the aspects that are model-dependent and estimate the upper limit of the PBH density in the universe and in the Galaxy. We then suggest methods to detect the γ, ν bursts from PBHs. Finally, we compare with the current data on γ-ray bursts (GRBs) and point out that some of the events may have the expected characteristics for PBH bursts within the distance of a few parsecs. Specific tests of this assumption are proposed which may be carried out in the next few years

EXTENDED TANH-METHODS AND SOLITONIC SOLUTIONS OF THE GENERAL SHALLOW WATER WAVE MODELS

Based on the two recent extended tanh-function methods, we find traveling-wave solutions for the general shallow water wave models. The obtained solutions include periodical, singular and solitary-wave solutions.

Nonthermal effects on the ion-acoustic solitons in Lorentzian electron-ion plasmas

The nonthermal effects on the propagation of the ion-acoustic soliton are investigated in generalized Lorentzian electron-ion plasmas. The soliton solution of the Korteweg–de Vries equation is obtained as a function of the spectral index and modified stretched coordinate in the generalized Lorentzian plasma. It is found that the nonthermal effect on the dispersive term is found to be stronger than that on the nonlinear term. It is shown that the nonthermal effect of the Lorentzian plasma strongly suppresses the stretched coordinate of the ion-acoustic soliton. It is also shown that the nonthermal effect increases the position of the ion-acoustic soliton. In addition, the nonthermal effects on the position of the ion-acoustic soliton are found to be more important in the forward direction. It is found that the nonthermal effect strongly suppresses the amplitude of the ion-acoustic soliton in Lorentzian electron-ion plasmas. It is also found that the nonthermal effect on the amplitude of the ion-acoustic so...

Electron spin-interaction effects on the ponderomotive magnetization and radiation in degenerate quantum plasmas

The spin interaction effects on the Karpman-Washimi ponderomotive magnetization are investigated in quantum plasmas. The induced Karpman-Washimi magnetization and cyclotron frequency due to the ponderomotive interaction are obtained as functions of the electron quantum wave length, Fermi wave number, wave frequency, and wave number. It is found that the spin interaction correction significantly enhances the Karpman-Washimi magnetization. It is also found the Karpman-Washimi magnetization increases with increasing Fermi wave number. In addition, it is found that the spin correction effect strongly enhances the radiation spectrum. It would be expected that the Karpman-Washimi interaction can be a possible terahertz radiation mechanism in a quantum plasma.

Electron-exchange and quantum screening effects on the collisional entanglement fidelity in degenerate quantum plasmas

The influence of electron-exchange and quantum screening on the collisional entanglement fidelity for the elastic electron–ion collision is investigated in degenerate quantum plasmas. The effective Shukla–Eliasson potential and the partial wave method are used to obtain the collisional entanglement fidelity in quantum plasmas as a function of the electron-exchange parameter, Fermi energy, plasmon energy and collision energy. The results show that the quantum screening effect enhances the entanglement fidelity in quantum plasmas. However, it is found that the electron-exchange effect strongly suppresses the collisional entanglement fidelity. Hence, we have found that the influence of the electron-exchange reduces the transmission of quantum information in quantum plasmas. In addition, it is found that, although the entanglement fidelity decreases with an increase of the Fermi energy, it increases with increasing plasmon energy in degenerate quantum plasmas.

Influence of the oscillatory quantum screening on the occurrence scattering time in electron-ion quantum plasmas

The oscillatory quantum screening effects on the occurrence scattering time advance for the electron-ion collision are investigated in dense quantum plasmas. The eikonal method is applied to obtain the scattering amplitude and occurrence scattering time advance for the electron-ion collision in quantum plasmas. The result shows that the oscillatory screening effect suppresses the occurrence scattering time advance for the electron-ion collision in quantum plasmas, especially, for large scattering angles. It is also found that the oscillatory screening effect on the occurrence scattering time advance increases with an increase of the collision energy.

Two-component spatial holographic solitons supported by cross-phase modulation

We have investigated two-component spatial holographic optical solitons supported solely by cross-phase modulation of two copropagating mutually coherent optical beams in the absence of the self phase modulation effects. We have identified a wide parameter space of power and spatial widths which captures the existence of a plethora of these stationary composite solitons including a bistable variety. Additionally, we have shown that these bistable solitons can exist only if their widths are above a certain minimum value. Our analytical results have been verified by direct numerical simulation of the coupled nonlinear Schrodinger equations.

Analytic Solitary-wave Solutions for Modified Korteweg - de Vries Equation with t-dependent Coefficients

Abstract We find analytic solitary wave solutions for a modified KdV equation with t-dependent coefficients of the form ut - 6α(t)uux + ß (t) uxxx -6γu2ux = 0. We make use of both the application of the truncated Painleve expansion and symbolic computation to obtain an auto-Bäcklund transformation. We show that kink-type analytic solitary-wave solutions exist under some constraints on α (t), ß (t) and γ.