Search for dissertations about: "symmetries"

Showing result 1 - 5 of 125 swedish dissertations containing the word symmetries.

2. 1. Symmetries and conservation laws

   Author : Raisa Khamitova; Börje Nilsson; Claes Jougréus; Maria Luz Gandarias; Växjö universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; conservation law; Noether s theorem; Lie group analysis; Lie-Bäcklund transformations; basis of conservation laws; formal Lagrangian; self-adjoint equation; quasi-selfadjoint; equation; nonlocal conservation law; Mathematical physics; Matematisk fysik;

   Abstract : Conservation laws play an important role in science. The aim of this thesis is to provide an overview and develop new methods for constructing conservation laws using Lie group theory. The derivation of conservation laws for invariant variational problems is based on Noether’s theorem. READ MORE

4. 2. Symmetries in Random Trees

   Author : Christoffer Olsson; Stephan Wagner; Michael Drmota; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Abstract : .... READ MORE

5. 3. Strings, Branes and Symmetries

   Author : Anders Westerberg; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Lie-algebra cohomology; Reggeon vertices; extended objects; string theory; p -branes; current algebra; supersymmetry; sewing; pseudodifferential operators; D-branes;

   Abstract : Recent dramatic progress in the understanding of the non-perturbative structure of superstring theory shows that extended objects of various kinds, collectively referred to as p-branes, are an integral part of the theory. In this thesis, comprising an introductory text divided in two parts and seven appended research papers (Papers I-VII), we study various aspects of p-branes with relevance for superstring theory. READ MORE

6. 4. Quivers, superconformal field theories and higher symmetries

   Author : Robert Moscrop; Michele Del Zotto; Johannes Walcher; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum field theory; Supersymmetry; Conformal field theory; Quivers; Seiberg-Witten theory; Geometric engineering; Higher symmetries; Theoretical Physics; Teoretisk fysik; Machine learning; Maskininlärning;

   Abstract : Quantum field theory (QFT) currently provides our best description of the natural world. Over the past century, it has been able to accurately reproduce many experimental results to an astonishing degree of accuracy and predict the existence of new particles. Despite this, QFT suffers from several mathematical problems. READ MORE

7. 5. Periodic Structures with Higher Symmetries: Analysis and Applications

   Author : Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

   Abstract : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. READ MORE