摘要:

An investigation is made of the properties of periodic and solitary waves for a simple atmospheric model.

ISSN:0022-2526    

DOI:10.1002/sapm19796011

年代:1979

数据来源: WILEY

摘要:

For density waves in a certain simplified model of a disk shaped galaxy, the dominant term of the basic equation (governing density waves) may be represented by a cubic polynomial, in which the stability parameterQis allowed to be somewhat less than unity near corotation. For such a differential equation, an asymptotic form of the global dispersion relation is presented. It is shown that there exist discrete complex roots of the dispersion relation with small negative imaginary parts. The real parts and the imaginary parts of these roots represent approximately the angular speeds and the growth rate of the amplitudes of the density waves, respectively. It is proved that there exist only a finite number of unstable normal modes of density waves.

ISSN:0022-2526    

DOI:10.1002/sapm197960111

年代:1979

数据来源: WILEY

摘要:

This paper is concerned with the response of nonlinear wave systems to external forcing by a uniform train of sinusoidal waves. In particular the stability of the forced solution is studied and other resonant situations are investigated.

ISSN:0022-2526    

DOI:10.1002/sapm197960127

年代:1979

数据来源: WILEY

摘要:

A detailed analysis is given to the solution of the cubic Schrödinger equationiqt+qxx+ 2|q|2q= 0 under the boundary conditions as |x|→∞. The inverse‐scattering technique is used, and the asymptotic state is a series of solitons. However, there is no soliton whose amplitude is stationary in time. Each soliton has a definite velocity and “pulsates” in time with a definite period. The interaction of two solitons is considered, and a possible extension to the perturbed periodic wave [q(x+T,t) =q(x,t) as |x|→∞

ISSN:0022-2526    

DOI:10.1002/sapm197960143

年代:1979

数据来源: WILEY

摘要:

The asymptotic solution of the Korteweg‐de Vries equationuτ+ ⅓uxxx+ 2uux= 0 for initial conditions from which no solitons evolve is obtained as a slowly varying similarity solution of the formτ−2/3(Vz−V2, whereV=V(z/τ) andz=τ−1/3x. The results are consistent with, but go somewhat beyond, those recently obtained by Ablowitz and Segur [2] through a rather diffe

ISSN:0022-2526    

DOI:10.1002/sapm197960159

年代:1979

数据来源: WILEY

摘要:

We use the Hirota's technique to find the multi‐soliton solutions of some nonlinear evolution equations. The interaction of the solitons is studie

ISSN:0022-2526    

DOI:10.1002/sapm197960173

年代:1979

数据来源: WILEY

摘要:

A random walk on the set of integers {0,1,2,...,a} with absorbing barriers at 0 andais considered. The transition times from the integersz(0

ISSN:0022-2526    

DOI:10.1002/sapm197960183

年代:1979

数据来源: WILEY