dark energy

03/30/2012 - 08:52

At the UK-Germany National Astronomy Meeting NAM2012, the Baryon Oscillation Spectroscopic Survey (BOSS) team today announced the most accurate measurement yet of the distribution of galaxies between five and six billion years ago. This was the key 'pivot' moment at which the expansion of the universe stopped slowing down due to gravity and started to accelerate instead, due to a mysterious force dubbed ”dark energy". The nature of this ”dark energy" is one of the big mysteries in cosmology today, and scientists need precise measurements of the expansion history of the universe to unravel this mystery – BOSS provides this kind of data.

03/20/2012 - 11:43

An exploding star known as a Type Ia supernova plays a key role in our understanding of the universe. Studies of Type Ia supernovae led to the discovery of dark energy, which garnered the 2011 Nobel Prize in Physics. Yet the cause of this variety of exploding star remains elusive.

01/09/2012 - 15:20

Two teams of physicists at the U.S. Department of Energy’s Fermilab and Lawrence Berkeley National Laboratory (Berkeley Lab) have independently made the largest direct measurements of the invisible scaffolding of the universe, building maps of dark matter using new methods that, in turn, will remove key hurdles for understanding dark energy with ground-based telescopes.

08/13/2011 - 15:05

Type Ia supernovae are violent stellar explosions whose brightness is used to determine distances in the universe. Observing these objects to billions of light years away has led to the discovery that the universe is expanding at an accelerating rate, the foundation for the notion of dark energy. Although all Type Ia supernovae appear to be very similar, astronomers do not know for certain how the explosions take place and whether they all share the same origin. Now, researchers have examined new and detailed observations of 41 of these objects and concluded that there are clear signatures of gas outflows from the supernova ancestors, which do not appear to be white dwarfs.