## Search

Now showing items 1-10 of 11

#### Spherically symmetric charged Einstein-Maxwell solutions.

(1999)

In this thesis we study spherically symmetric spacetimes with a perfect fluid source
which incorporates charge. We seek explicit solutions to the Einstein- Maxwell system
of equations. For nonaccelerating spherically ...

#### Noether's theorem and first integrals of ordinary differential equations.

(1997)

The Lie theory of extended groups is a practical tool in the analysis of differential equations, particularly in the construction of solutions. A formalism of the Lie theory is given and contrasted with Noether's theorem ...

#### Algebraic properties of ordinary differential equations.

(1995)

In Chapter One the theoretical basis for infinitesimal transformations is
presented with particular emphasis on the central theme of this thesis which
is the invariance of ordinary differential equations, and their first ...

#### Coherent structures and symmetry properties in nonlinear models used in theoretical physics.

(1994)

This thesis is devoted to two aspects of nonlinear PDEs which are fundamental
for the understanding of the order and coherence observed in the underlying physical
systems. These are symmetry properties and soliton ...

#### Ermakov systems : a group theoretic approach.

(1993)

The physical world is, for the most part, modelled using second order ordinary differential equations. The time-dependent simple harmonic oscillator and the Ermakov-Pinney equation (which together form an Ermakov system) ...

#### The paradigms of mechanics : a symmetry based approach.

(1996)

An overview of the historical developments of the paradigms of classical mechanics, the free particle, oscillator and the Kepler problem, is given ito (in terms of) their conserved quantities. Next, the orbits of the three ...

#### Extensions and generalisations of Lie analysis.

(1995)

The Lie theory of extended groups applied to differential equations is arguably one of the most successful methods in the solution of differential equations. In fact, the theory unifies a number of previously unrelated ...

#### Parameters related to fractional domination in graphs.

(1995)

The use of characteristic functions to represent well-known sets in graph theory such as dominating, irredundant, independent, covering and packing sets - leads naturally to fractional versions of these sets and corresponding ...

#### Fischer-Clifford theory and character tables of group extensions.

(1998)

The smallest Fischer sporadic simple group Fi22 is generated by a conjugacy class D of 3510 involutions called 3-transpositions such that the product of any noncommuting pair is an element of order 3. In Fi22 there are ...