A group of scientists questions whether the universe was formed after the Big Bang

Astrophysicists from the University of Cambridge, the University of Trento and Harvard University point out that the universe was not created with the big bang, as until now had been believed . In fact, they point out that this cosmic inflation “can be ruled out without assumption,” they say in a new Article published in ‘The Astrophysical Journal Letters’.

Instead of the familiar Big Bang, scientists point out that there is a clear and unequivocal sign that the cosmos would have had at the beginning of its existence another sign, a cosmic graviton background or CGB. This phenomenon could be detected in a feasible way, as they describe, although it would be a “great technical and scientific challenge”.

“Inflation was theorized to explain various tuning challenges of the so-called hot Big Bang model,” explains the paper’s author, Sunny Vagnozzi. “It also explains the origin of structure in our universe as a result of quantum fluctuations,” he tells the University of Cambridge.

Therefore, for astrophysicists the explanation of the Big Bang shows too many possible models, “an unlimited panorama of cosmological results”. So, for both Vagnozzi and his colleagues, cosmic inflation could be ruled out without assumptions.

Cosmic inflation | A. Ijjas, P. J. Steinhardt, and A. Loeb (“Scientific American,” February 2017)

As early as 2013, some scientists became concerned about this cosmic inflation when the Planck satellite published its first measurements of the cosmic microwave background, the oldest light in the universe. So, Vagnozzi argues, other astrophysicists argued that “the results could be showing the opposite.”

Contrary theory to the Big Bang

For Vagnozzi and his team, inflation posed more puzzles than it solved, so they began to consider new ideas about the early universe. For example, it could have started not with a bang, but with a ricochet of a cosmos that was contracted previously.

The Big Bang model allows “see” up to the previous 100 million years that the first stars formed. “The true edge of the observable universe is the distance that any signal could have traveled at the speed of light limit during the 13.8 billion years since the birth of the universe,” explains another of the authors, Avi Loeb.

“As a result of the expansion of the universe, this edge is currently at 46.5 billion light years away. The spherical volume within this boundary is like an archaeological dig centered on us: the deeper we probe it, the earlier the layer of cosmic history we uncover, all the way back to the Big Bang that represents our latest horizon. What lies beyond the horizon is unknown,” he continues.

The team of astrophysicists therefore believe that it is possible to delve even deeper into the early universe by studying neutrinos, which are almost weightless particles in the universe that traveled freely for one second after the Big Bang. “The current universe must be full of relic neutrinos from that time,” says Vagnozzi.

Furthermore, both Vagnozzi and Loeb say that what happened earlier in the universe could still be investigated by tracking gravitons, other particles that measure the strength of gravity. They indicate that a gravitational thermal radiation relic with a temperature of just under a degree above absolute zero: the cosmic graviton background.

However, the Big Bang theory does not allow the existence of the CGB, since it suggests that the exponential inflation of the newborn universe diluted relics like the CGB to the point where they are undetectable. This can be turned into a test: if the CGB were detected, this would clearly rule out cosmic inflation, which does not allow its existence.


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