Theory of Everything best candidate theory
ABU DHABI: The Khalifa University research team investigated the effects of gravitational lensing on two black holes in a C-metric. A C-metric describes space-time with two black holes; one black hole here in this universe and one in a parallel universe. The two black holes have equal mass and are accelerating away from each other at a constant rate as a ‘cosmic string’ pulls the black holes apart. The team realised that the black holes in a C-metric would scater light rays in such a way that would allow for gravitational lensing to detect them.
“There are two kinds of gravitational lensing: weak and strong lensing,” explained Dr. Batic. “Weak lensing occurs when the light rays emanating from the source pass at a distance from the gravitational object in the middle. Strong lensing occurs when the light rays travel very close to the gravitational source, and particularly when close to a special distance from the object called the photon sphere.”
While weak lensing for two uncharged black holes connected by a cosmic string is too small to be detected, strong lensing would indeed work, and the team went on to calculate the formula for detecting black holes in this way.
Their computations found that a weak lensing analysis applied to a supermassive black hole or anything smaller cannot discriminate what kind of metric is being represented. However, their new equations represent the general formula for using black holes in strong gravitational lensing and can be used with observational data to confirm or disprove the existence of black holes described by a C-metric.
“In order to understand the relevance of our result, we need to remember that in theoretical physics, String Theory or the Theory of Everything is our best candidate theory which brings together quantum mechanics with general relativity,” explained Dr. Batic. “Among several predictions provided by String Theory, we also find the so-called cosmic strings. If cosmic strings are observed by means of our theoretical predictions, this would provide the first experimental evidence of a string theory model underlying the structure of spacetime.”