Chris Doran

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A new gauge theory of gravity is presented. The theory is constructed in a flat background spacetime and employs gauge fields to ensure that all relations between physical quantities are independent of the positions and orientations of the matter fields. In this manner all properties of the background spacetime are removed from physics, and what remains are(More)
Over the past 2-3 years, clinical practice guidelines (CPGs) for post-traumatic stress disorder (PTSD) and acute stress disorder (ASD) have been developed in the USA and UK. There remained a need, however, for the development of Australian CPGs for the treatment of ASD and PTSD tailored to the national health-care context. Therefore, the Australian Centre(More)
A new form of the Kerr solution is presented. The solution involves a time coordinate which represents the local proper time for free-falling observers on a set of simple trajectories. Many physical phenomena are particularly clear when related to this time coordinate. The chosen coordinates also ensure that the solution is well behaved at the horizon. The(More)
Projective geometry provides the preferred framework for most implementations of Euclidean space in graphics applications. Translations and rotations are both linear transformations in projective geometry, which helps when it comes to programming complicated geometrical operations. But there is a fundamental weakness in this approach — the Euclidean(More)
This paper contains a tutorial introduction to the ideas of geometric algebra , concentrating on its physical applications. We show how the definition of a 'geometric product' of vectors in 2-and 3-dimensional space provides precise geometrical interpretations of the imaginary numbers often used in conventional methods. Reflections and rotations are(More)
OBJECTIVE Empowerment is a complex process of psychological, social, organizational and structural change. It allows individuals and groups to achieve positive growth and effectively address the social and psychological impacts of historical oppression, marginalization and disadvantage. The Growth and Empowerment Measure (GEM) was developed to measure(More)
We compute the spectrum of normalized fermion bound states in a Schwarzschild black hole background. The eigenstates have complex energies. The real part of the energies, for small couplings, closely follow a Hydrogen-like spectrum. The imaginary contributions give decay times for the various states, due to the absorption properties of the hole. As(More)
The differential cross section for scattering of a Dirac particle in a black hole background is found. The result is the gravitational analog of the Mott formula for scattering in a Coulomb background. The equivalence principle is neatly embodied in the cross section, which depends only on the incident velocity, and not the particle mass. The low angle(More)