Many theoretical frameworks used to explain quantum gravity and other cosmological phenomena, including string theory, require extra dimensions. Some use space-time as a single extra dimension, while others use several extra space-time dimensions.
In a new study, researchers suggest evidence of extra dimensions could be hiding in gravitational waves. Scientists at the Max Planck Institute for Gravitational Physics theorized how these extra dimensions might influence the space-time ripples, with hopes of directly observing their predictions.
Astrophysicists believe LIGO, the gravitational wave-detection system, can help them study gravity itself.
"Compared to the other fundamental forces like, e.g. electromagnetism, gravity is extremely weak," David Andriot, one of the authors of the new study, said in a news release.
Theories of quantum gravity, such as string theory, attempt to bring the predictions and premises of quantum mechanics into agreement with those of general relativity. Extra dimensions help quantum gravity theories explain the behaviour of large masses as infinitesimal scales.
"Physicists have been looking for extra dimensions at the Large Hadron Collider at CERN but up to now this search has yielded no results," said study co-author Gustavo Lucena Gómez. "But gravitational wave detectors might be able to provide experimental evidence."
Scientists at the Albert Einstein Institute predicted that extra dimensions would alter the "standard" gravitational wave, as well as trigger the propagation of additional waves at frequencies above 1000 Hz. Unfortunately, LIGO is capable of detecting such high-frequency waves.
However, researchers are hopeful that LIGO, with the help of the forthcoming Virgo detector, will help scientists detect the ways in which extra dimensions alter the stretching and shrinking of space-time in standard gravitational waves.
The team of astrophysicists detailed their work in a new paper, published this week in the Journal of Cosmology and Astroparticle Physics.