Sökning: "perturbation-theory"

Visar resultat 16 - 20 av 97 avhandlingar innehållade ordet perturbation-theory.

1. 16. Non-linear Spectroscopy of Conical Intersections with XUV and X-ray Photons

   Författare :Deependra Jadoun; Markus Kowalewski; Faris Gelmukhanov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conical Intersections; Non-linear Spectroscopy; Quantum Dynamics; Perturbation Theory; Ultrafast Spectroscopy; X-ray; XUV; Theoretical Physics; teoretisk fysik;

   Sammanfattning : Conical intersections (CIs) appear in a molecule due to the breakdown of the Born-Oppenheimer approximation when the energy difference between two or more electronic states decreases. CIs are known to play a crucial role in processes such as photosynthesis and vision in the human eye, and therefore it is important to probe the existence of such entities in molecules. LÄS MER

3. 17. Software tools for matrix canonical computations and web-based software library environments

   Författare :Pedher Johansson; Bo Kågström; Erik. Elmroth; Alan Edelman; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canonical structure; Jordan canonical form; controllability; StratiGraph; Matlab toolbox; Kronecker canonical form; matrix; matrix pencil; perturbation theory; closure hirerarchy; matrix stratification; control system; observability; Numerical analysis; Numerisk analys;

   Sammanfattning : This dissertation addresses the development and use of novel software tools and environments for the computation and visualization of canonical information as well as stratification hierarchies for matrices and matrix pencils. The simplest standard shape to which a matrix pencil with a given set of eigenvalues can be reduced is called the Kronecker canonical form (KCF). LÄS MER

4. 18. Capacity Analysis and Receiver Design in the Presence of Fiber Nonlinearity

   Författare :Kamran Keykhosravi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perturbation theory.; Achievable rate; nonlinearity mitigation; noncoherent optics; dispersion compensation; fiber optics; channel capacity; information theory;

   Sammanfattning : The majority of today's global Internet traffic is conveyed through optical fibers. The ever-increasing data demands have pushed the optical systems to evolve from using regenerators and direct-direction receivers to a coherent multi-wavelength network. LÄS MER

5. 19. Computation of Parameters in some Mathematical Models

   Författare :Gunilla Wikström; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; inverse problems; parameter estimation; systems of ordinary differential equations; short-cut methods; separable nonlinear least squares problems; Matlab toolbox for nonlinear least squares ; linear systems of equations; pseudoinverse solution; perturbation theory; singular value decomposition; experimental error analysis; Computer science; Datavetenskap;

   Sammanfattning : In computational science it is common to describe dynamic systems by mathematical models in forms of differential or integral equations. These models may contain parameters that have to be computed for the model to be complete. LÄS MER

7. 20. Infinite order perturbation theory with applications to atomic and molecular systems

   Författare :Erkki Brändas; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : .... LÄS MER