822 research outputs found
BLP dissipative structures in plane
We study the Darboux and Laplace transformations for the
Boiti-Leon-Pempinelli equations (BLP). These equations are the (1+2)
generalization of the sinh-Gordon equation. In addition, the BLP equations
reduced to the Burgers (and anti-Burgers) equation in a one-dimensional limit.
Localized nonsingular solutions in both spatial dimensions and (anti) "blow-up"
solutions are constructed. The Burgers equation's "dressing" procedure is
suggested. This procedure allows us to construct such solutions of the BLP
equations which are reduced to the solutions of the dissipative Burgers
equations when . These solutions we call the BLP dissipative
structures.Comment: 7 pages, AMS-Te
The Day the Universes Interacted: Quantum Cosmology without a Wave function
In this article we present a new outlook on the cosmology, based on the
quantum model proposed by M. Hall, D.-A. Deckert and H. Wiseman (HDW). In
continuation of the idea of that model we consider finitely many classical
homogeneous and isotropic universes whose evolutions are determined by the
standard Einstein-Friedman equations but that also interact with each other
quantum-mechanically via the mechanism proposed by HDW. The crux of the idea
lies in the fact that unlike every other interpretation of the quantum
mechanics, the HDW model requires no decoherence mechanism and thus allows the
quantum mechanical effects to manifest themselves not just on micro-scale, but
on a cosmological scale as well. We further demonstrate that the addition of
this new quantum-mechanical interaction lead to a number of interesting
cosmological predictions, and might even provide natural physical explanations
for the phenomena of ``dark matter'' and ``phantom fields''.Comment: 15 pages, RevTeX, 3 figure
The Landau-Lifshitz equation, the NLS, and the magnetic rogue wave as a by-product of two colliding regular "positons"
In this article we present a new method for construction of exact solutions
of the Landau-Lifshitz-Gilbert equation (LLG) for ferromagnetic nanowires. The
method is based on the established relationship between the LLG and the
nonlinear Schr\"odinger equation (NLS), and is aimed at resolving an old
problem: how to produce multiple-rogue wave solutions of NLS using just the
Darboux-type transformations. The solutions of this type - known as P-breathers
- have been proven to exist by Dubard and Matveev, but their technique heavily
relied on using the solutions of yet another nonlinear equation,
Kadomtsev-Petviashvili I equation (KP-I), and its relationship with NLS. We
have shown that in fact one doesn't have to use KP-I but can instead reach the
same results just with NLS solutions, but only if they are dressed via the
binary Darboux transformation. In particular, our approach allows to construct
all the Dubard-Matveev P-breathers. Furthermore, the new method can lead to
some completely new, previously unknown solutions. One particular solution that
we have constructed describes two positon-like waves, colliding with each other
and in the process producing a new, short-lived rogue wave. We called this
unusual solution (rogue wave begotten after the impact of two solitons) the
"impacton".Comment: 25 pages, 9 figures. Added Section 7 ("7. One last remark: But what
of generalization?.."), corrected a number of typos, added 2 more reference
- …