The abstract boundary construction of Scott and Szekeres has proven a practical
classification scheme for boundary points of pseudo-Riemannian manifolds. It
has also proved its utility in problems associated with the re-embedding of exact
solutions containing directional singularities in space-time. Moreover it provides
a model for singularities in space-time - essential singularities. However the literature
has been devoid of abstract boundary results which have results of direct
physical applicability.¶
This thesis presents several theorems on the existence of essential singularities
in space-time and on how the abstract boundary allows definition of optimal em-
beddings for depicting space-time. Firstly, a review of other boundary constructions
for space-time is made with particular emphasis on the deficiencies they possess for
describing singularities. The abstract boundary construction is then pedagogically
defined and an overview of previous research provided.¶
We prove that strongly causal, maximally extended space-times possess essential
singularities if and only if they possess incomplete causal geodesics. This result
creates a link between the Hawking-Penrose incompleteness theorems and the existence of essential singularities. Using this result again together with the work of
Beem on the stability of geodesic incompleteness it is possible to prove the stability
of existence for essential singularities.¶
Invariant topological contact properties of abstract boundary points are presented
for the first time and used to define partial cross sections, which are an
generalization of the notion of embedding for boundary points. Partial cross sections
are then used to define a model for an optimal embedding of space-time.¶
Finally we end with a presentation of the current research into the relationship
between curvature singularities and the abstract boundary. This work proposes
that the abstract boundary may provide the correct framework to prove curvature
singularity theorems for General Relativity. This exciting development would culminate over 30 years of research into the physical conditions required for curvature singularities in space-time.
| Identifer | oai:union.ndltd.org:ADTP/216773 |
| Date | January 2002 |
| Creators | Ashley, Michael John Siew Leung, ashley@gravity.psu.edu |
| Publisher | The Australian National University. Faculty of Science |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.anu.edu.au/legal/copyrit.html), Copyright Michael John Siew Leung Ashley |
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