Search for dissertations about: "Dirac theory"

Showing result 1 - 5 of 27 swedish dissertations containing the words Dirac theory.

2. 1. Interacting Dirac Matter

   Author : Saikat Banerjee; Alexander V. Balatsky; Jens Paaske; KTH; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Dirac; superconductor; magnon; interaction; Fermi liquid theory; renormalization; Fysik; Physics;

   Abstract : The discovery of graphene in 2004 has led to a surge of activities focused on the theoretical and experimental studies of materials hosting linearly dispersive quasiparticles during the last decade. Rapid expansion in the list of materials having similar properties to graphene has led to the emergence of a new class of materials known as the Dirac materials. READ MORE

4. 2. Resonances of Dirac Operators

   Author : Jimmy Kungsman; Wolfgang Staubach; Roman Schubert; Uppsala universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Semiclassical analysis; Dirac operator; resonances; Poisson trace formula; scattering theory; complex absorbing potential; pseudodifferential operator; Mathematics; Matematik;

   Abstract : This thesis consists of a summary of four papers dealing with resonances of Dirac operators on Euclidean 3-space. In Paper I we show that the Complex Absorbing Potential (CAP) method is valid in the semiclassical limit for resonances sufficiently close to the real line if the potential is smooth and compactly supported. READ MORE

5. 3. The Dirac Equation: Numerical and Asymptotic Analysis

   Author : Hasan Almanasreh; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
   Keywords : Dirac operator; eigenvalue problem; finite element method; spurious eigenvalues; Petrov-Galerkin; cubic Hermite basis functions; stability parameter; meshfree method; $hp$-cloud; intrinsic enrichment; G-convergence; $ Gamma$-convergence; scattering theory; identification; wave operator; stationary approach;

   Abstract : The thesis consists of three parts, although each part belongs to a specific subject area in mathematics, they are considered as subfields of the perturbation theory. The main objective of the presented work is the study of the Dirac operator; the first part concerns the treatment of the spurious eigenvalues in the computation of the discrete spectrum. READ MORE

6. 4. Resolvent Estimates and Bounds on Eigenvalues for Schrödinger and Dirac Operators

   Author : Alexandra Enblom; Vladimir Kozlov; Ari Laptev; David Krejcirik; Linköpings universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; Schrödinger operators; polyharmonic operators; Dirac operators; non-self-adjoint perturbations; complex potential; estimation of eigenvalues; Carleman inequalities; Hardy inequalities;

   Abstract : This thesis concerns the spectral theory of Schrödinger and Dirac operators. The main results relate to the problems of estimating perturbed eigenvalues. The thesis is based on four papers.The first paper focuses on the problem of localization of perturbed eigenvalues for multidimensional Schrödinger operators. READ MORE

7. 5. The Dirac Operator; From Numerics to the Theory of G-convergence

   Author : Hasan Almanasreh; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dirac operator; spuriousity; cubic Hermitian; stability parameter; G-convergence; ¡-convergence; spectral measure; quadratic form;

   Abstract : We consider two main issues concerning the Dirac operator, the first is widely known as the appearance of spurious eigenvalues within the spectrum. The second is the study of the asymptotic behavior of the eigenvalues for a family of Dirac operators with oscillatory potential added to the Coulomb-Dirac Hamiltonian. READ MORE