Sökning: "Nonlinear Schrödinger equation"
Visar resultat 6 - 10 av 11 uppsatser innehållade orden Nonlinear Schrödinger equation.
6. On the variational characterization of quasi-periodic standing waves of the nonlinear Schrödinger equation
Kandidat-uppsats, Lunds universitet/Matematik (naturvetenskapliga fakulteten)Sammanfattning : We consider quasi-periodic standing wave solutions U(t, x) = exp(i(ωt−px))Ψ(x) to the one-dimensional defocusing cubic nonlinear Schrödinger equation, where we assume that Ψ : R → C is 2π−periodic. We study a constrained minimization problem associated with these solutions, and we show that solutions with minimal period of Ψ(x) strictly less than 2π cannot be minimizers, whereas locally the minimum is obtained among those solutions with minimal period 2π. LÄS MER
7. Two variational problems related to the nonlinear Schrödinger equation
Kandidat-uppsats, Lunds universitet/Matematik (naturvetenskapliga fakulteten)Sammanfattning : The nonlinear Schrödinger equation is a partial differential equation which appears as a model in several branches of physics, including Bose-Einstein condensation and hydrodynamics. In this thesis, we investigate a particular class of solutions, namely periodic standing waves. LÄS MER
8. Numerical continuation of standing waves for the Davey-Stewartson equation
Master-uppsats, Lunds universitet/Matematik (naturvetenskapliga fakulteten)Sammanfattning : This thesis considers solitary standing wave solutions to the Davey-Stewart-son equation, which is a model for surface waves on a body of water in three dimensions. In a special case, the Davey-Stewartson equation is reduced to the well-known non-linear Schrödinger equation with cubic power which is known to have a countable familiy of radial standing waves. LÄS MER
9. Model of a Wave Diode in a Nonlinear System
Kandidat-uppsats, Linköpings universitet/Teoretisk Fysik; Linköpings universitet/Tekniska högskolanSammanfattning : In this diploma work, two versions of the discrete nonlinear Schrödinger (DNLS) equation are used to model a nonlinear layered photonic crystal system; the cubic DNLS (cDNLS) equation and the saturable DNLS (sDNLS) equation. They both have site-dependent coefficients to break mirror symmetry with respect to propagation direction, as well as to describe the linear and nonlinear properties of the system. LÄS MER
10. Characterization of attractors in a model for boundary-driven nonlinear optical waveguide arrays with disorder, gain and damping
Kandidat-uppsats, Teoretisk Fysik; Tekniska högskolanSammanfattning : The purpose of this thesis is to study the effects of gain and damping on a nonlinear waveguide array with a strong disorder that is driven in the first site, and try to find regimes which have stable stationary solutions. This has been done with a modified DNLS (Discrete nonlinear Schrödinger equation). LÄS MER
