Scientists believed that the universe is expanding at a faster because of the dark energy, but the recent study has suggested that the universe is not expanding as fast as it was believed but at a lower rate, this indicates that there is less dark energy in the universe.
Astronomers at the University of Arizona have studied on this subject and this has raised many questions like how fast is the universe accelerating after the Big Bang, which occurred around 14 billion years ago.
They have collected the data using NASA Swift satellite.
They have discovered that the type of supernova which is used to measure reliable distances in the universe fell into different populations previously unknown.
The amount of light absorbed by the la supernova varied more than previously thought.
Researchers said that the findings are analogous to sampling of 100 watt light bulbs at the hardware store and discovering that they vary in brightness.
Peter A Milne, who led the team at UA said, “We found that the differences are not random, but lead to separating Ia supernovae into two groups, where the group that is in the minority near us are in the majority at large distances – and thus when the universe was younger.
There are different [red and blue] populations out there, and they have not been recognized. The big assumption has been that as you go from near to far, type Ia supernovae are the same. That doesn’t appear to be the case.”
Milne has observed la supernova in visible and ultraviolet light and combined the data with the data from Hubble telescope and Swift satellite.
Milne said, “The idea behind this reasoning is that type Ia supernovae happen to be the same brightness – they all end up pretty similar when they explode. Once people knew why, they started using them as mileposts for the far side of the universe. The faraway supernovae should be like the ones nearby because they look like them, but because they’re fainter than expected, it led people to conclude they’re farther away than expected, and this in turn has led to the conclusion that the universe is expanding faster than it did in the past.”
He said, that the data they obtained said there might be less dark energy. Before the two populations were treated as the same population.
The research couldn’t pinpoint what such results mean for the current measure of dark energy which is 73 percent of the universe.