Search for dissertations about: "Lorentz operator"

Showing result 1 - 5 of 8 swedish dissertations containing the words Lorentz operator.

2. 1. Forever Young : Convolution Inequalities in Weighted Lorentz-type Spaces

   Author : Martin Křepela; Sorina Barza; Javier Soria; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Convolution; Young inequality; Lorentz spaces; weights; rearrangement-invariant spaces; Matematik; Mathematics;

   Abstract : This thesis is devoted to an investigation of boundedness of a general convolution operator between certain weighted Lorentz-type spaces with the aim of proving analogues of the Young convolution inequality for these spaces.Necessary and sufficient conditions on the kernel function are given, for which the convolution operator with the fixed kernel is bounded between a certain domain space and the weighted Lorentz space of type Gamma. READ MORE

4. 2. Modelling and measuring transport in fusion plasmas

   Author : Istvan Pusztai; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; fusion plasmas; ITG stability; microinstabilities; de-convolution; Lorentz operator; gyrokinetic equation; transport; quasilinear flux; beam emission spectroscopy; ion temperature gradient mode; electron density measurement; trapped electron response;

   Abstract : In the present thesis we consider theoretical and experimental aspects of the turbulent transport which is a crucial issue in fusion plasma physics.Experimental observations and gyrokinetic simulations show that collisions strongly influence the turbulent flux of particles. READ MORE

5. 3. The Weighted Space Odyssey

   Author : Martin Křepela; Sorina Barza; Gord Sinnamon; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; integral operators; supremal operators; weights; weighted function spaces; Lorentz spaces; Lebesgue spaces; convolution; Hardy inequality; multilinear operators; nonincreasing rearrangement; Matematik; Mathematics;

   Abstract : The common topic of this thesis is boundedness of integral and supremal operators between weighted function spaces.The first type of results are characterizations of boundedness of a convolution-type operator between general weighted Lorentz spaces. READ MORE

6. 4. On Lorentz Invariance, Regularity and Global Existence for Kinetic Equations

   Author : Håkan Andreasson; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : [A1] Regularity of the gain term and strong L1 convergence to equilibrium for the relativistic Boltzmann equation. The main purpose of the paper is to show that the gain term of the relativistic collision operator is regularizing. This is a generalization of P.L. READ MORE

7. 5. On various aspects of extended objects

   Author : Mariusz Hynek; Jens Hoppe; Volker Bach; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Abstract : This thesis concerns classical and quantum aspects of minimal manifolds embedded in flat Minkowski space. In particular, we study the Lie algebra of diffeomorphisms on 2 dimensional compact manifolds as well as discuss singularity formation for relativistic minimal surfaces in co-dimension one. READ MORE