Browsing Department of Mathematics and Physics (TNIMF) by Document Types "Doctoral thesis"
Now showing items 116 of 16

Bridgeland Stability Conditions and the Hilbert Scheme of Skew Lines in Projective Space
(PhD thesis UiS;, Doctoral thesis, 202303)Bridgeland stability conditions are powerful tools for studying derived categories, with several applications to algebraic geometry. They were introduced by Bridgeland in 2002 [Bri07], who was motivated by Douglas’ work ... 
Direct and reciprocal space structure modelling: Contributions to the advanced understanding of inclusion compounds
(PhD thesis UiS;, Doctoral thesis, 202205)The main content of this thesis falls naturally into one of two parts. The chapters come in an order which follows the research development, but encapsulates single topics enough to allow the reader some flexibility. In ... 
Equivalences between Calabi–Yau manifolds and roofs of projective bundles
(PhD thesis UiS;, Doctoral thesis, 202104)It is conjectured that many birational transformations, called Kinequalities, have a categorical counterpart in terms of an embedding of derived categories. In the special case of simple Kequivalence (or more generally ... 
Essays in statistics and econometrics
(PhD thesis UiS; 523, Doctoral thesis, 202005)Helped by cheaper data computation, companies make more use of sophisticated statistical analysis in decision making and economic management. In the dissertation I evaluate and develop statistical methods and apply them ... 
The experimental and theoretical investigation of singlecrystal diamond compound refractive lenses (CRLs)
(PhD theses (TNIMF);527, Doctoral thesis, 202006)In the field of Xray optics, compound refractive lenses (usually termed CRLs) function as a focusing device for hard Xrays and they are believed to possess a lot of prominent advantages over other focusing devices, such ... 
From Symmetries to Scattering Amplitudes: A Liealgebraic categorisation of symmetrybreaking patterns that create enhanced soft limits for NG bosons
(PhD thesis UiS;, Doctoral thesis, 202211)The standard calculation of scattering amplitudes in quantum field theory is carried out using a perturbative expansion, that at successive orders contains an escalating number of terms to calculate. The amplitudes depend ... 
Information in Local Curvature: Three Papers on Adaptive Methods in Computational Statistics
(PhD thesis UiS;562, Doctoral thesis, 202011)Advanced statistical computations have become increasingly important, as with the increased flexibility of models capturing complex relationships in new data and usecases, comes increased difficulties of fitting procedures ... 
Investigation of crystal field, magnetic frustration and magnetization reversal effects in 4f and 3d oxides
(PhD thesis UiS;, Doctoral thesis, 202209)This thesis deals with the investigation of singleion excitations, magnetic frustration, and magnetization reversal phenomena. We have employed neutron scattering, μ+SR, and computational methods for these studies. Inverse ... 
An Investigation of SecondOrder Finite Volume Methods for Fieldscale Reservoir Simulation
(PhD thesis UiS;, Doctoral thesis, 2024)This thesis focuses on improving the accuracy of numerical simulation of flow in subsurface reservoirs by using secondorder finite volume methods. The firstorder finite volume method, commonly used in reservoir simulation, ... 
A mathematical approach to Wick rotations
(PhD thesis UiS;536, Doctoral thesis, 202009)In this thesis we define Wickrotations mathematically using pseudoRiemannian geometry, and relate Wickrotations to real geometric invariant theory (GIT). We discover some new results concerning the existence of Wick ... 
NilKilling vector fields and Kundt structures
(PhD thesis UiS;529, Doctoral thesis, 202006)This thesis is based on three papers, for which two have been submitted for publication and one is published. A chapter presenting relevant background material is included giving convenient access to preliminary foreknowledge ... 
Nonequilibrium quantum field dynamics in the early Universe
(PhD thesis UiS;, Doctoral thesis, 2023)Inflation is the leading paradigm of early Universe cosmology. It provides compelling explanations of the observed nearhomogeneity of the cosmic microwave background (CMB) radiation, the spatial flatness of the Universe ... 
Properties of Paley–Wiener spaces: sampling sets, contractions, and geometry of the unit ball
(PhD thesis UiS;, Doctoral thesis, 202303)This Thesis is based on five papers, four of which are published and one has been submitted for publication. For convenience of the reader, we also include one chapter that contains a brief overview of the results, some ... 
RealTime Complex Langevin  A Differential Programming Perspective
(PhD thesis UiS;, Doctoral thesis, 2023)In this thesis, I aim to find solutions to the NPhard signproblem that arises when modeling strongly correlated systems in realtime. I will use the complex Langevin (CLE) method, and address its problem of runaway ... 
Signal analysis in gravitational wave data
(PhD thesis UiS;, Doctoral thesis, 2024)In this thesis, I study the gravitational wave signals coming from compact objects on both presentstage, and future gravitational wave detectors. The thesis is based on 3 articles, which will be presented after two brief ... 
Tales from Wonderland
(Doctoral thesis, 202006)Knowing that the Universe is quite isotropic, one may, as already discussed in Chapter 1, wonder how likely such a Universe is. We take the following research question. Question 1. Is the asymptotic future of a cosmology ...