Browsing Doctoral Degrees (Applied Mathematics) by Title
Now showing items 38-57 of 61
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Modelling waterborne diseases.
(2013)Waterborne diseases are among the major health problems threatening the life of individuals globally. This thesis investigates the dynamics of waterborne disease under different conditions and consequently determines ... -
Models in isotropic coordinates with equation of state.
(2014)In this thesis we consider spacetimes which are static and spherically symmetric related to the Einstein and Einstein-Maxwell system of equations in isotropic coordinates. We study both neutral and charged matter ... -
New exact solutions for neutral and charged shear-free relativistic fluids.
(2022)We study shear-free gravitating fluids in general relativity. We first analyse the integrability of the Emden-Fowler equation that governs the behaviour of shear-free neutral perfect fluid distributions. We find a new ... -
New models for quark stars with charge and anisotropy.
(2014)We find new classes of exact solutions for the Einstein-Maxwell field equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field ... -
New solutions for a radiating star.
(2018) -
Non-circularity of beams in the CMB polarization power spectrum estimation.
(2013)Precise measurements of the Cosmic Microwave Background (CMB) anisotropies have been one of the foremost concerns in modern cosmology as it provides valuable information on the cosmology of the Universe. However, an ... -
A numerical study of heat and mass transfer in non-Newtonian nanofluid models.
(2019)A theoretical study of boundary layer flow, heat and mass transport in non-Newtonian nanofluids is presented. Because of the diversity in the physical structure and properties of non-Newtonian fluids, it is not possible ... -
On new and improved semi-numerical techniques for solving nonlinear fluid flow problems.
(2012)Most real world phenomena is modeled by ordinary and/or partial differential equations. Most of these equations are highly nonlinear and exact solutions are not always possible. Exact solutions always give a good account ... -
On paired decoupled quasi-linearization methods for solving nonlinear systems of differential equations that model boundary layer fluid flow problems.
(2018)Two numerical methods, namely the spectral quasilinearization method (SQLM) and the spectral local linearization method (SLLM), have been found to be highly efficient methods for solving boundary layer flow problems that ... -
On singularly perturbed problems and exchange of stabilities.
(2015)Singular perturbation theory has been used for about a century to describe models displaying different timescales, that arise in applied sciences; particularly, models displaying two timescales, namely slow time and fast ... -
Optimisation of the population Monte Carlo algorithm : application to cosmology.
(2015)In this thesis we study the Population Monte Carlo (PMC) algorithm and utilise simulations to improve the efficiency of the algorithm by optimising the algorithm parameters. We then ap ply these optimisation results to ... -
Partial exchangeability and related topics.
(1991)Partial exchangeability is the fundamental building block in the subjective approach to the probability of multi-type sequences which replaces the independence concept of the objective theory. The aim of this thesis is ... -
Probing the nature of dark energy with 21-cm intensity mapping.
(2020)Two approaches to measure the BAOs (baryon acoustic oscillations) with optical and radio telescopes, namely; galaxy redshift and intensity mapping (IM) surveys have been introduced and discussed in the literature. Among ... -
Relativistic astrophysical models of perfect and radiating fluids.
(2019)Abstract available in PDF file. -
Relativistic radiating stars with generalised atmospheres.
(2010)In this dissertation we construct radiating models for dense compact stars in relativistic astrophysics. We first utilise the standard Santos (1985) junction condition to model Euclidean stars. By making use of the ... -
Role of Weyl tensor and spacetime shear in relativistic fluids.
(2021)The main gravitational theory in which we develop this work is general relativity. We study the role of the Weyl tensor in general relativistic fluid motion including the e↵ects of spacetime shear. Firstly we consider ... -
Scalar perturbations of Schwarzschild black holes in modified gravity.
(2017)This thesis is concerned with the physics related to scalar perturbations in the Schwarzschild geometry that arise in modifed gravity theories. It has already been shown that the gravitational waves emitted from a ... -
Thermal evolution of radiation spheres undergoing dissipative gravitational collapse.
(2014)In this study we investigate the physics of a relativistic radiating star undergoing dissipative collapse in the form of a radial heat flux. Our treatment clearly demonstrates how the presence of shear affects the collapse ...