Summary of Research Activity
Gravitational Field of Circulating Light Beams
In Einstein's general theory of relativity, energy as well as matter produces gravity. This means that the energy of a pure light beam can gravitationally affect matter. A portion of my current research deals with considering the gravitational field produced by a single continuously circulating beam of light in a unidirectional ring laser. It is predicted that a spinning neutral particle, when placed in the ring, is dragged around by the resulting gravitational field (Mallett, R.L. 2000. Weak gravitational field of the electromagnetic radiation in a ring laser. Phys. Lett. A 269: 214).
Calculations show that, for light circulating in a transparent dielectric medium, the gravitational frame dragging precession rate is inversely proportional to the velocity of light in the medium. This opens up the possibility that slow light experiments, such as those of Lene Hau and her collaborators, may be used to detect this gravitational effect.
Another aspect of this research explores the gravitational effect of two circulating light beams. A new and exact solution of Einstein's gravitational field equations is found for a nonrotating circular energy source. This solution can be used to represent the gravitational field generated the standing waves of two counterpropogating light beams. It can be shown that, by the proper adjustment of beam intensity and slow light velocity, closed loops in time can be formed.
Cosmic Degenerate Bose-Einstein Dark Matter
In collaboration with Mark P. Silverman of the Department of Physics of Trinity College, a general relativistically covariant theory of a self coupled scalar field has been developed as a possible solution of the missing mass problem. We have shown that spontaneous symmetry breaking of a neutral scalar field coupled to gravity leads directly to ultra-low mass bosons, with a critical temperature far above the temperature of the universe, for most of its duration. The particles are therefore expected to condense into a degenerate Bose Einstein gas, providing a potential candidate for nonbaryonic nonluminous matter (Silverman, M.P. and R.L. Mallett. 2001. Cosmic degenerate matter: a possible solution to the problem of missing mass. Class. Quantum Grav. 18 L37).