London, Mar 21: The most detailed map ever created of the cosmic microwave background – the relic radiation from the Big Bang – obtained by the European Space Agency’s Planck space telescope has revealed the existence of features that challenge the foundations of our current understanding of the Universe.
The image, which has just been released, is based on the initial 15.5 months of data from Planck and is the mission’s first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380,000 years old.
This ‘cosmic microwave background’ – CMB – shows tiny temperature fluctuations that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today.
According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before. By analysing the nature and distribution of the seeds in Planck’s CMB image, we can determine the composition and evolution of the Universe from its birth to the present day.
Overall, the information extracted from Planck’s new map provides an excellent confirmation of the standard model of cosmology at an unprecedented accuracy, setting a new benchmark in our manifest of the contents of the Universe.
But because precision of Planck’s map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood.
One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model – their signals are not as strong as expected from the smaller scale structure revealed by Planck.
Another is an asymmetry in the average temperatures on opposite hemispheres of the sky. This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look.
“Our ultimate goal would be to construct a new model that predicts the anomalies and links them together. But these are early days; so far, we don’t know whether this is possible and what type of new physics might be needed. And that’s exciting,” Professor Efstathiou said. (ANI)