Search for dissertations about: "Hamiltonian systems"

Showing result 1 - 5 of 76 swedish dissertations containing the words Hamiltonian systems.

2. 1. Open Quantum Systems : Effects in Interferometry, Quantum Computation, and Adiabatic Evolution

   Author : Johan Åberg; Erik Sjöqvist; Sten Lunell; Vlatko Vedral; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Open Systems; Completely Positive Maps; Channels; Decoherence; Quantum Information; Quantum Computing; Adiabatic Approximation; Quantum Search; Time-Complexity; Fysik; Physics; Fysik;

   Abstract : The effects of open system evolution on single particle interferometry, quantum computation, and the adiabatic approximation are investigated.Single particle interferometry: Three concepts concerning completely positive maps (CPMs) and trace preserving CPMs (channels), named subspace preserving (SP) CPMs, subspace local channels, and gluing of CPMs, are introduced. READ MORE

4. 2. Symplectic methods for Hamiltonian isospectral flows and 2D incompressible Euler equations on a sphere

   Author : Milo Viviani; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fluid dynamics; Symplectic methods; Isospectral flows; Geometric integration; Hamiltonian systems; Structure preserving algorithms; Euler equations; Lie–Possion systems; Fluid dynamics.;

   Abstract : The numerical solution of non-canonical Hamiltonian systems is an active and still growing field of research. At the present time, the biggest challenges concern the realization of structure preserving algorithms for differential equations on infinite dimensional manifolds. Several classical PDEs can indeed be set in this framework. READ MORE

5. 3. Hamiltonian systems with Poisson commuting integrals

   Author : Håkan Eliasson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The purpose of this thesis is to study Hamiltonian systems with Poisson commuting integrals near a stationary point - a situation appearing in many problems of classical mechanics.It turns out that these integrals, under fairly general conditions on their quadratic parts, become singular (their gradients become linearly dependent) on symplectic submanifolds, giving rise to invariant manifolds for the Hamiltonian system - the singular manifolds. READ MORE

6. 4. Wave interactions by Hamiltonian methods

   Author : Krister Wiklund; Umeå universitet; []
   Keywords : Hamiltonian formulation; wave interaction; stability; variational principles;

   Abstract : This thesis is devoted to the description of fluids and gases from a Hamiltonian point of view. The method we apply is a development of the theory invented by Hamilton (1805-1865). The original formulation is restricted to a certain family of dynamical variables; the canonical variables. READ MORE

7. 5. On steady waves in two-layer fluids and ferrofluids

   Author : Dag Nilsson; Partiella differentialekvationer; []
   Keywords : Internal waves; ferrofluids; partial differential equation; nonlinear waves; travelling waves; solitary waves; dynamical systems; Hamiltonian systems; non-local equations;

   Abstract : This thesis concerns travelling waves in a two-layer fluid and on a ferrofluid jet. We prove existence of several types of such waves by reformulating the corresponding governing equation as an infinite dimensional dynamical system, where an unbounded spatial coordinate is used as time. READ MORE