Looking Back in Time to First 100 Years After Big Bang

Scientists at the Lawrence Berkeley National Laboratory have used a new analysis of cosmic microwave background (CMB) radiation to take a look back in time to the beginnings of our universe. The scientists report observable data that originated anywhere from 100 to 300,000 years after the Big Bang, a breakthrough they are calling the furthest look back through time ever accomplished.

The researchers hope to use the data to better understand the mysteries of the universe.

"We found that the standard picture of an early universe, in which radiation domination was followed by matter domination, holds to the level we can test it with the new data, but there are hints that radiation didn't give way to matter exactly as expected," said Eric Linder, a theoretical physicist with Berkeley Lab's Physics Division. "There appears to be an excess dash of radiation that is not due to CMB photons."

Virtually everything known to science about the Big Bang and the early formation of the universe comes from CMB measurements. CMB radiation consists of primordial photons that were set free when when the universe cooled enough for particles or radiation and particles of matter to separate.

By measuring CMB radiation, scientists can better understand its influence on the growth and large-scale structure we see in the universe today.

By using data from European Space Agency's Planck mission and NASA's Wilkinson Microwave Anisotropy Probe (WMAP), the scientists achieved CMB measurements of higher resolution, lower noise, and more sky coverage than ever before.

"With the Planck and WMAP data we're really pushing back the frontier and looking further back in the history of the universe, to regions of high energy physics we previously could not access," Linder said.

"While our analysis shows the CMB photon relic afterglow of the Big Bang being followed mainly by dark matter as expected, there was also a deviation from the standard that hints at relativistic particles beyond CMB light."

Likely contenders for the "relativistic particles" are rouge neutrinos that behave inconsistently with the known neutrino behavior today, and dark energy.

"Early dark energy is a class of explanations for the origin of cosmic acceleration that arises in some high energy physics models," Linder said. "While conventional dark energy, such as the cosmological constant, are diluted to one part in a billion of total energy density around the time of the CMB's last scattering, early dark energy theories can have 1-to-10 million times more energy density."

The present state of cosmic acceleration could have been driven by dark energy, Linder said, adding that its actual discovery would not only provide new insight into the origin of cosmic acceleration, but perhaps also provide new evidence for string theory and other concepts in high energy physics.

Linder and his colleagues research is published in the journal Physical Review Letters