9 research outputs found
Negative radiation pressure exerted on kinks
The interaction of a kink and a monochromatic plane wave in one dimensional
scalar field theories is studied. It is shown that in a large class of models
the radiation pressure exerted on the kink is negative, i.e. the kink is {\sl
pulled} towards the source of the radiation. This effect has been observed by
numerical simulations in the model, and it is explained by a
perturbative calculation assuming that the amplitude of the incoming wave is
small. Quite importantly the effect is shown to be robust against small
perturbations of the model. In the sine-Gordon (sG) model the time
averaged radiation pressure acting on the kink turns out to be zero. The
results of the perturbative computations in the sG model are shown to be in
full agreement with an analytical solution corresponding to the superposition
of a sG kink with a cnoidal wave. It is also demonstrated that the acceleration
of the kink satisfies Newton's law.Comment: 23 pages, 8 figures, LaTeX/RevTe
Some Recent Developments on Kink Collisions and Related Topics
We review recent works on modeling of dynamics of kinks in 1+1 dimensional
theory and other related models, like sine-Gordon model or
theory. We discuss how the spectral structure of small perturbations can affect
the dynamics of non-perturbative states, such as kinks or oscillons. We
describe different mechanisms, which may lead to the occurrence of the resonant
structure in the kink-antikink collisions. We explain the origin of the
radiation pressure mechanism, in particular, the appearance of the negative
radiation pressure in the and models. We also show that the
process of production of the kink-antikink pairs, induced by radiation is
chaotic.Comment: 26 pages, 9 figures; invited chapter to "A dynamical perspective on
the {\phi}4 model: Past, present and future", Eds. P.G. Kevrekidis and J.
Cuevas-Maraver; Springer book class with svmult.cls include
Creation of Kink and Antikink Pairs Forced By Radiation
The interaction between kink and radiation in nonlinear one-dimensional real
scalar field is investigated. The process of discrete vibrational mode
excitation in model is considered. The role of this oscillations in
creation of kink and antikink is discussed. Numerical results are presented as
well as some attempts of analytical explanations. An intriguing fractal
structure in parameter space dividing regions with creation and without is also
presented
Oscillons in gapless theories
We show that large scale oscillons, i.e., quasiperiodic, long-living particlelike solutions, may exist in massless theories, too. Their existence is explained using an effective (smeared) mass threshold which takesinto account nonlinear (finite) perturbations
Investigation of restricted baby Skyrme models
A restriction of the baby Skyrme model consisting of the quartic and
potential terms only is investigated in detail for a wide range of potentials.
Further, its properties are compared with those of the corresponding full baby
Skyrme models. We find that topological (charge) as well as geometrical
(nucleus/shell shape) features of baby skyrmions are captured already by the
soliton solutions of the restricted model. Further, we find a coincidence
between the compact or non-compact nature of solitons in the restricted model,
on the one hand, and the existence or non-existence of multi-skyrmions in the
full baby Skyrme model, on the other hand.Comment: latex, 18 pages, 2 figures; some typos correcte