Search for dissertations about: "variational states"

Showing result 1 - 5 of 10 swedish dissertations containing the words variational states.

  1. 1. Resonant states in modulation-doped heterostructures

    University dissertation from Anders Blom, Sölvegatan 14 A, S-223 62 Lund, Sweden

    Author : Anders Blom; Lund University.; Lunds universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematical and general theoretical physics; generation-recombination noise; THz laser; classical mechanics; relativity; quantum mechanics; statistisk fysik; gravitation; relativitet; kvantmekanik; klassisk mekanik; Matematisk och allmän teoretisk fysik; thermodynamics; termodynamik; statistical physics; donor energies; Si SiGe quantum well; central-cell effect; impurity absorption; Fysicumarkivet A:2003:Blom; Resonant states; impurity levels;

    Abstract : This thesis deals with the properties of donors placed inside or outside a heterostructure quantum well (QW). The focus of the investigation has been on the formation of resonant states, which are a hybridization of the discrete localized impurity levels and the continuous two-dimensional QW subbands. READ MORE

  2. 2. Four-Body Treatment of the Hydrogen-Antihydrogen System

    University dissertation from Uppsala : Uppsala universitet

    Author : Henrik Stegeby; Uppsala universitet.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Antimatter; antihydrogen; four-body system; Adiabatic approximation; Born-Oppenheimer; elastic scattering; stabilization method; resonance states; coupled arrangement channels; coupled rearrangement channels; Gaussian Expansion Method; Antimateria; antiväte; fyrkroppars system; adiabatisk approximation; stabilisationsmetoden; resonanstillstånd; spridningstillstånd; kopplade arrangemangskanaler; Quantum Chemistry; Kvantkemi;

    Abstract : This thesis presents a nonadiabatic (4-body) description of the hydrogen-antihydrogen system at a nonrelativistic level. The properties of the system, the rearrangement processes and the possible existence of resonance states are investigated by using a variational method for coupled arrangement channels, the Gaussian Expansion Method, and the stabilization method. READ MORE

  3. 3. Wave interactions by Hamiltonian methods

    University dissertation from Umeå : Umeå universitet

    Author : Krister Wiklund; Umeå universitet.; [2002]
    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

  4. 4. Adaptive Finite Element Methods for Optimal Control Problems

    University dissertation from Göteborg : Chalmers University of Technology

    Author : Karin Kraft; Göteborgs universitet.; Gothenburg University.; [2011]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; discontinuous Galerkin method; optimal control; a posteriori error estimate; dual weighted residual; adaptive; multilevel algorithm; Newton method; control constraint; variational inequality; vehicle dynamics.;

    Abstract : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a systemof differential equations, the state equations, which are governed bya control variable. The goal is to determine the states and controls which minimize a given cost functional. READ MORE

  5. 5. Foundation of Density Functionals in the Presence of Magnetic Field

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Andre Laestadius; KTH.; [2014]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Current density functional theory; Hohenberg-Kohn theorems; paramagnetic current density functionals; Kohn-Sham theory; Levy-Lieb functional; variational principle; N-representable; degeneracy; Matematik; Mathematics;

    Abstract : This thesis contains four articles related to mathematical aspects of Density Functional Theory.In Paper A, the theoretical justification of density methods formulated with current densities is addressed. It is shown that the set of ground-states is determined by the ensemble-representable particle and paramagnetic current density. READ MORE