Fergie's Tech Blog

'Cyclic Universe' Can Explain Cosmological Constant

Zeeya Merali writes on NewScientistSpace:

A cyclic universe, which bounces through a series of big bangs and "big crunches", could solve the puzzle of our cosmological constant, physicists suggest.

The cosmological constant represents the energy of empty space, and is thought to be the most likely explanation for the observed speeding up of the expansion of the universe. But its measured value is a googol (1 followed by 100 zeroes) times smaller than that predicted by particle physics theories. It is a discrepancy that gives cosmologists a real headache.

In the 1980s, physicists considered the possibility that an initially large cosmological constant could decay down to the value measured today. But this theory was abandoned when calculations showed that it would take far longer than 14 billion years – the time since the big bang – for the constant to reach the level seen today.

Now physicists Paul Steinhardt at Princeton University, in New Jersey, US, and Neil Turok at Cambridge University in the UK, are resurrecting the idea. They point out that if time stretches back beyond the big bang, the problem could be solved. At that is just what is predicted by their cyclic model of the universe – an alternative to the Standard Big Bang theory – which the pair first developed in 2002.

posted by Fergie @ 5/04/2006 11:23:00 AM