We present a new, fully covariant and manifestly gauge-invariant expression for the temperature anisotropy in the cosmic microwave background radiation resulting from scalar perturbations. We pay particular attention to gauge issues such as the definition of the temperature perturbation and … Continued
We consider a fully relativistic method for the calculation of tunnelling times based on the streamlines of the conserved probability flux. This method is similar to that proposed by Leavens but is not based on the Bohmian interpretation. The method … Continued
We present new, massive, non-ghost solutions for the Dirac field coupled self-consistently to gravity. We employ a gauge-theoretic formulation of gravity which automatically identifies the spin of the Dirac field with the torsion of the gauge fields. Homogeneity of the … Continued
We discuss three applications of a gauge theory of gravity to rotating astrophysical systems. The theory employs gauge fields in a flat Minkowski background spacetime to describe gravitational interactions. The iron fluorescence line observed in AGN is discussed, assuming that … Continued
A lecture course in geometric algebra delivered at a summer school in Banff, Canada, 1996. A. N. Lasenby, C. J. L. Doran and S. F. Gull, Lectures in Geometric Algebra, In W. E. Baylis, editor, Clifford (Geometric) Algebras with Applications to Physics, Mathematics … Continued
An objective account of the action of a Stern-Gerlach apparatus on spin-1/2 particles is given, using the Dirac equation. This generalizes earlier work on a causal interpretation of the Pauli equation to the relativistic domain, leading to a more natural … Continued
Clifford’s ‘geometric algebra‘ is presented as the natural language for expressing geometrical ideas in mathematical physics. Its spacetime version ‘spacetime algebra‘ is introduced and is shown to provide a powerful, invariant description of relativistic physics. Applications to electromagnetism and gravitation … Continued
A new gauge-theoretic approach to gravity is applied to the study of rotating cylindrically-symmetric strings. The interior and exterior equations are reduced to a simple set of first-order differential equations, and suitable matching conditions are obtained. The gauge theory formulation … Continued
This paper surveys the application of `geometric algebra’ to the physics of electrons. The mathematical ideas underlying geometric algebra were discovered jointly by Clifford and Grassmann in the late 19th century. Their discoveries were made during a period in which … Continued
A new gauge-theory description of gravity is presented, employing gauge fields in a flat background spacetime. These fields ensure that all physical relations are independent of the position and orientation of the matter fields in this background. The language of … Continued