Scientists discover ‘cosmic glitch’ at the edge of the cosmos

Have researchers discovered a “cosmic glitch” in the gravity of the universe? That’s exactly what a team in Canada believes after finding that Albert Einstein’s general theory of relativity doesn’t quite match up with what astronomers are observing at the edge of the universe!

Einstein’s famed theory has been the mainstay of modern physics for 100 years, aiding to explain how gravity works here on Earth and out in space. Furthermore, countless studies have proven this theory to be precise over the years — confirming that gravity affects our three physical dimensions and also the fourth dimension of time.“This model of gravity has been essential for everything from theorizing the Big Bang to photographing black holes,” explains Robin Wen (the lead author of the project and a recent Waterloo Mathematical Physics graduate), in a university release.

“But when we try to understand gravity on a cosmic scale, at the scale of galaxy clusters and beyond, we encounter apparent inconsistencies with the predictions of general relativity. It’s almost as if gravity itself stops perfectly matching Einstein’s theory. We are calling this inconsistency a ‘cosmic glitch’: gravity becomes around one percent weaker when dealing with distances in the billions of light years.”

The study, put out in the Journal of Cosmology and Astroparticle Physics, examined the likelihood that the strength of gravity governing the entire cosmos (the cosmological gravitational constant) is somewhat different than Newton’s gravitational constant that governs gravity on smaller scales, such as the orbit of planets around the Sun.“Almost a century ago, astronomers discovered that our universe is expanding,” notes NiayeshAfshordi (a professor of astrophysics at the University of Waterloo and researcher at the Perimeter Institute).“The farther away galaxies are, the faster they are moving, to the point that they seem to be moving at nearly the speed of light, the maximum allowed by Einstein’s theory. Our finding suggests that, on those very scales, Einstein’s theory may also be insufficient.”

So, why would scientists even ponder about such a wild idea to modify Einstein’s revolutionary theory? It turns out some alternate quantum gravity theories like Hořava-Lifshitz gravity naturally envisage such a cosmic glitch between large and small scales. The fresh study provides a simple way of implementing this effect like “a footnote” to the standard cosmological model.

Wen and his associates introduced a single new parameter called Omega_g that quantifies the variance between the cosmological and Newtonian gravitational constants. They found out that current observations from the Planck satellite measuring the cosmic microwave background radiation favor a value of Omega_g around -0.01, or around a one-percent difference in the strength of gravity across cosmic scales compared to local scales.