Search for dissertations about: "invariant theory"

Showing result 1 - 5 of 135 swedish dissertations containing the words invariant theory.

2. 1. Homotopy Theory and TDA with a View Towards Category Theory

   Author : Sebastian Öberg; Wojciech Chachólski; David Blanc; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Homotopy theory; Topological Data Analysis; Category theory; Mapping spaces; Homotopy commutative diagrams; Matematik; Mathematics;

   Abstract : This thesis contains three papers. Paper A and Paper B deal with homotopy theory and Paper C deals with Topological Data Analysis. All three papers are written from a categorical point of view.In Paper A we construct categories of short hammocks and show that their weak homotopy type is that of mapping spaces. READ MORE

4. 2. Yang-Mills Theory in Gauge-Invariant Variables and Geometric Formulation of Quantum Field Theories

   Author : Sergey Slizovskiy; Antti Niemi; Andrey Losev; Andrey Marshakov; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Yang-Mills theory; spin-charge separation; Kaluza-Klein theory; branes; curved beta-gamma systems; Mathematical physics; Matematisk fysik; Theoretical Physics; Teoretisk fysik;

   Abstract : In Part I we are dealing with effective description of Yang-Mills theories based on gauge-invarint variables. For pure Yang-Mills we study the spin-charge separation varibles. The dynamics in these variables resembles the Skyrme-Faddeev model. READ MORE

5. 3. Strings, Conformal Field Theory and Noncommutative Geometry

   Author : Keizo Matsubara; Anton Alekseev; Edwin Langmann; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; Theoretical physics; String theory; Conformal field theory; Noncommutative geometry; Star-products; Teoretisk fysik; Physics; Fysik;

   Abstract : This thesis describes some aspects of noncommutative geometry and conformal field theory. The motivation for the investigations made comes to a large extent from string theory. This theory is today considered to be the most promising way to find a solution to the problem of unifying the four fundamental interactions in one single theory. READ MORE

6. 4. Defects, renormalization and conformal field theory

   Author : Alexander Söderberg Rousu; Agnese Bissi; Pedro Liendo; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; defects; boundaries; replica twist defect; conformal field theory; quantum field theory; Coleman-Weinberg mechanism; renormalization group flows; Theoretical Physics; Teoretisk fysik;

   Abstract : Defects in quantum field theories appear in many different contexts and are of great physical interest. Among other things, defects are used to describe the Kondō effect in condensed matter, confinement in quantum chromodynamics, Rényi entropy in quantum information and cosmic strings in string theory. READ MORE

7. 5. On Rank-invariant Methods for Ordinal Data

   Author : Yishen Yang; Sune Karlsson; Elisabeth Svensson; Rolf Larsson; Örebro universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ordinal data; rank-invariance; systematic change; agreement; association; inter-rater reliability; ranking; Spearman; multi-item scale; Statistik; Statistics;

   Abstract : Data from rating scale assessments have rank-invariant properties only, which means that the data represent an ordering, but lack of standardized magnitude, inter-categorical distances, and linearity. Even though the judgments often are coded by natural numbers they are not really metric. READ MORE