Search for dissertations about: "Wigner"

Showing result 6 - 10 of 33 swedish dissertations containing the word Wigner.

2. 6. Aspects of Wave Interaction in Nonlinear Media

   Author : Björn Hall; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear Schrödinger equation; incoherent solitons; partial incoherence; nonlinear wave interaction; Gross-Pitaevskii equation; modulational instability; collective dynamics; Wigner transform; nonlinear guided waves; Bose-Einstein condensation;

   Abstract : Selected aspects of various types of nonlinear wave interaction are investigated. These aspects are studied in terms of models described by Nonlinear Schrödinger equations, mainly analytically and numerically, but also experimentally. READ MORE

4. 7. Nonlinear Dynamics of Coherent and Partially Coherent Optical Waves

   Author : Tobias Hansson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; soliton interaction; Wigner transform; logarithmically saturable media; Nonlinear Schrödinger equation; parabolic beams; partial coherence; quasilinear diffusion; modulational instability;

   Abstract : In optics an important nonlinear effect is manifested by the fact that the refractive index, in addition to its frequency dependence, also depends on the intensity of the light. Nonlinear effects are present within a wide range of optical applications e.g. the fast growing fields of fiber-optic communication and all-optical signal processing. READ MORE

5. 8. Nonlinear Theory of Partially Coherent Optical Waves

   Author : Tobias Hansson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; partial coherence; beam collapse; saturable logarithmic media; soliton interaction; dressing method; parabolic beams; Wigner transform; invariants; modulational instability;

   Abstract : Nonlinear effects arise in optics as a consequence of the medium properties being modified by the presence of light. Of particular interest are situations where the effect of the nonlinearity can be described by an intensity dependent refractive index and the subsequent interplay with dispersion and diffraction. READ MORE

6. 9. Multivariable Orthogonal Polynomials as Coupling Coefficients for Lie and Quantum Algebra Representations

   Author : Hjalmar Rosengren; Matematik (naturvetenskapliga fakulteten); []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; higher order Hankel form; Wigner symbol; quadratic algebra; Clebsch-Gordan coefficient; quantum group; Lie group; highest weight representation; multivariable orthogonal and biorthogonal polynomials; multivariable hypergeometric and basic hypergeometric functions; algebraisk topologi; Geometry; Geometri; algebraic topology;

   Abstract : The main topic of the thesis is the connection between representation theory and special functions. We study matrix elements, coupling coefficient, and recoupling coefficients for the simplest Lie and quantum groups. READ MORE

7. 10. Photodetachment spectroscopy : negative ion bound states and resonances Gunnar Haeffler

   Author : Gunnar Haeffler; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; electron correlation; electron affinity; shape resonance; fine structure; ion optics; photodetachment; resonance ionization spectroscopy RIS ; Wigner law; doubly excited state; Feshback resonance; negative ion; electron spectroscopy;

   Abstract : .... READ MORE