Dark energy tagged posts

Andromeda Galaxy (stock image). Credit: © passmil198216 / Fotolia

Quest to settle riddle over Einstein’s theory may soon be over. Tests using advanced technology could resolve a longstanding puzzle over what is driving the accelerated expansion of the Universe. Researchers have long sought to determine how the Universe’s accelerated expansion is being driven. Calculations in a new study could help to explain whether dark energy- as required by Einstein’s theory of general relativity – or a revised theory of gravity are responsible.

Einstein’s theory, which describes gravity as distortions of space and time, included a Cosmological Constant...

This is the “South Pillar” region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope “busted open” this murky cloud to reveal star embryos tucked inside finger-like pillars of thick dust. Credit: NASA

Physicists have proposed that violations of energy conservation in the early universe, as predicted by certain modified theories of quantum mechanics and quantum gravity, may explain the cosmological constant problem, which is sometimes referred to as “the worst theoretical prediction in the history of physics.” “The main achievement of the work was the unexpected relation between two apparently very distinct issues, namely the accelerated expansion of the universe and microscopic physics,” Josset said.

Einstein ...

New research confirms the role Type Ia supernovae, like G299 pictured above, play in measuring universe expansion. Courtesy ofNASAdownload

New research by cosmologists at the University of Chicago and Wayne State University confirms the accuracy of Type Ia supernovae in measuring the pace at which the universe expands. The findings support a widely held theory that the expansion of the universe is accelerating and such acceleration is attributable to a mysterious force known as dark energy. The findings counter recent headlines that Type Ia supernova cannot be relied upon to measure the expansion of the universe.

Using light from an exploding star as bright as entire galaxies to determine cosmic distances led to the 2011 Nobel Prize in physics...

The universe may not be expanding at an accelerating rate, as previously thought, but rather, at a constant rate, suggests new research. (Stock image) Credit: © watoson / Fotolia

5 years ago, the Nobel Prize in Physics was awarded to 3 astronomers for their discovery, in 1990s, that the universe is expanding at an accelerating pace. Their conclusions were based on analysis of Type Ia supernovae – the spectacular thermonuclear explosion of dying stars – picked up by the Hubble and large ground-based telescopes. It led to the widespread acceptance of the idea that the universe is dominated by ‘dark energy’ that drives this accelerating expansion.

Now, a team led by Prof Subir Sarkar of Oxford University’s Dept of Physics has cast doubt on this standard cosmological concept...