Showing papers in "Physica D: Nonlinear Phenomena in 1980"

TL;DR: In this article, it was shown that the 2-point (resp. 2n-point) function or the 1-particle reduced density matrix satisfies a non-linear differential equation of Painleve type.

TL;DR: In this paper, the degeneracy structure of the eigenangle spectrum is related to the distribution of cycle lengths, and the quantal Wigner function shows that eigenstates of U do not correspond to individual cycles.

TL;DR: In this paper, a semi-quantitative interpretation of these processes and their relation with the different transitions to turbulence observed experimentally are discussed. But their results are restricted to the case where σ = 10, b = 8 3 and r r = 145 and r = 148.

TL;DR: In this article, the setting of several important current problems in the physics of condensed matter (solids, liquids) is reviewed, and the concepts embodied in the mathematical analysis of solitons provide systematic new insight into a central question: what are the important physical configurations in nonlinear condensed systems?

TL;DR: In this article, the authors examined the stability of two-iteration fixed points in detail, including the bifurcation sequence for one type of mapping, which is a member of a class of mappings which retains some KAM trajectories at arbitrarily large nonlinearity.

TL;DR: In this paper, the average occupation numbers of the state with momentum k of a homogeneous nonlinear medium with dispersion law co(k) were introduced to describe the nonlinearity of the medium.

TL;DR: In this paper, the theory of Hamiltonian systems with symmetry is applied to dynamical systems like the nonperiodic Toda Lattice of Moser to yield striking information about their trajectories.

TL;DR: In this paper, the irrotational nonrelativistic case is presented and some of the advantages of the fluid point-of-view are mentioned, as well as the advantages for the fluid perspective.

TL;DR: The direct and inverse scattering solution for the full three dimensional three-wave resonant interaction was solved in this paper, and an infinite set of conservation laws were found for the three-dimensional resonant interactions.

TL;DR: In this paper, a simple 2-dimensional mapping is considered, both analytically and numerically, for which all nonlinear effects are of the same order as the perturbations and origin.

TL;DR: In this paper, a survey article on instantons and monopoles is presented for those who have no prior knowledge of Yang-Mills gauge field theories, with minimal amount of physical motivation and mathematical apparatus.

TL;DR: The Estabrook-Wahlquist method can be used as a semidirect method for starting with a given nonlinear partial differential equation, and if it would happen to be exactly solvable, allowing one to find the required method of solution as discussed by the authors.

TL;DR: In this paper, the forced Van der Pol equation is used as an example of a relaxation oscillation with aperiodic solutions, and the technique of symbolic dynamics, particularly for one-dimensional mappings, is used to give a complete topological characterization of the set of these periodic solutions for parameter values for which the equation appears structurally stable.

TL;DR: In this paper, a single fluxon on a semi-infinite Josephson line is reflected at a passive or an active termination, and an analytical approximation based on energy analysis is developed.

TL;DR: In this article, the authors simulated large amplitude motion in cyclic one-dimensional lattices of Morse potential oscillators with a mass impurity, and observed an unexpected persistence of solitary wave behavior for which they were unable to discover a satisfactory explanation.

TL;DR: In this article, the authors considered the non-stationary behavior of a wave at the nonadiabatic stage using a Galerkin procedure, where the wave form becomes essentially nonstationary (breaking of stationary wave structure).

TL;DR: In this paper, numerical examples show that the degree of stochasticity does not always increase monotonically with increasing energy, and that at high energies the diagonal anharmonicities (nonlinearities) dominate the off-diagonal (coupling) terms.

TL;DR: In this paper, it was shown that the partition function of the 2-dimensional Ising model in the presence of a magnetic field can be expressed in terms of the distributions of the prime numbers in closed form.

TL;DR: In this paper, the authors consider perturbation theory in ϵ for the classical Hamiltonian H = H 0 + ϵH 1, where H 0 gives rise to a known motion and ϵ is small.

TL;DR: In this article, it was shown that the two-parameter manifold of Backlund transformations known for the nonlinear Schrodinger equation can be generated from one Backlund transformation with specified parameters by use of scale transformation and Galilean transformation.

TL;DR: In this paper, a particle model based on a classical minimum action principle is derived, which is shown to be the analogue of the fine structure constant α = e 2 / h c, and a pair of coupled partial differential equations of the second order must be solved.

TL;DR: In this paper, exact analytic solutions describing the equilibrium states available to a one-dimensional, self-gravitating cloud of gas subject to an external constant gravitational acceleration due to a plane of "stars" are presented.