Wai Bong Yeung

Spontaneous compactification in a six-dimensional Poincaré gauge field theory of gravitation

Abstract We found a solution for the torsion tensor in a six-dimensional Poincare gauge theory of gravitation. This torsion tensor supports a Riemann-Cartan geometry which is the product of a minkowskian four-space and a two-sphere whose radius is determined by the field equations to be of the order of the Planck length. This solution exists when there are some restrictions on the parameters of the lagrangian of the theory.

Kaluza-Klein electric monopole in a six-dimensional poincaré gauge theory of gravitation

Abstract We found a solution to the six-dimensional Poincare gauge theory that can be interpreted as the gravitational field and the electric field of an electric monopole in four-dimensional spacetime. The extra dimensions are curled up into a compact space of a size characterized by the Planck length.

Solution for the five-dimensional general relativity that simulates a charged macroscopic object in four dimensions

SummaryWe found a solution in the five-dimensional genaral relativity that effectively gives the gravitational and electric fields of a four-dimensional macroscopic object. The motions of both uncharged and charged test particles are shown to follow the five-dimensional geodesic equations with different integration constants.

A Wu-Yang monopole in an asymptotically flat Riemann-Cartan spacetime☆

Abstract We found that the Wu-Yang monopole can exist in an asymptotically flat Riemann-Cartan spacetime whose dynamics is governed by the Poincare gauge theory of gravitation.

Kaluza-Klein black hole in a six-dimensional Poincaré gauge theory of gravitation

Abstract We found a solution to the six-dimensional Poincare gauge theory which can be interpreted as the exterior gravitational field of an uncharged black hole in the four-dimensional spacetime. The extra dimensions are curled up into a compact space of the size characterized by the Planck length.

Rotonless solutions in the Poincaré gauge theory of gravitation

Abstract In searching for rotonless solutions to the full equations of the Poincare gauge theory of gravitation under spherically symmetric conditions, we found a unique set of lagrangians for the theory in which the absence of rotons will give the Schwarzschild metric as the only possible metric solution to the field equations.

A fast algorithm for the perturbative calculation of the ground-state energy of the quantum-mechanical anharmonic oscillator

SummaryWe apply the logarithmic perturbation theory to derive a recursive formula for the ground-state energy of the quantum-mechanical anharmonic oscillator. This formula is particularly handy for the computer to do.

The extra dimensions of the eleven-dimensional simple supergravity are ricci-flat if they are compact

SummaryBy using the de Rham-Yano-Bochner lemma on harmonic tensor fields in a compact orientable manifold, we show that the extra dimensions in eleven-dimensional simple supergravity will he Ricci-flat if they are compact.