“Einstein 13-Billion-Years Ago” –Three-Thousand Early-Universe Galaxies Confirm Relativity



Since it was discovered in the late 1990s that the universe is expanding at an accelerated rate, scientists have been trying to explain why. The mysterious dark energy could be driving acceleration, or Einstein’s theory of general relativity, which says gravity warps space and time, could be breaking down. An international team led by Japanese researchers has made a 3D map of 3000 galaxies 13 billion light years from Earth, and found that Einstein’s general theory of relativity is still valid.

No one has been able to analyze galaxies more than 10 billion light years away, but the team managed to break this barrier thanks to the FMOS (Fiber Multi-Object Spectrograph) on the Subaru Telescope, which can analyze galaxies 12.4 to 14.7 billion light years away. The Prime Focus Spectrograph, currently under construction, is expected to be able to study galaxies even further away.




To test Einstein’s theory, the team of researchers led by Kavli Institute for the Physics and Mathematics (Kavli IPMU) used FastSound Survey data on more than 3000 distant galaxies to analyze their velocities and clustering. The 3-D map above shows the universe spanning 12 to 14.5 billion light years.

Their results indicated that even far into the universe, general relativity is valid, giving further support that the expansion of the universe could be explained by a cosmological constant, as proposed by Einstein in his theory of general relativity.

“We tested the theory of general relativity further than anyone else ever has. It’s a privilege to be able to publish our results 100 years after Einstein proposed his theory,” said Kavli Institute project researcher Teppei Okumura. “



The image at the top of the page shows an exceedingly rare triple system, seen when the Universe was only 800 million years old. The trio provides important insights into the earliest stages of galaxy formation during a period known as ‘Cosmic Dawn,’ “when the Universe was first bathed in starlight,” said Richard Ellis, the Steele Professor of Astronomy at the California Institute of Technology. “Even more interesting, these galaxies appear poised to merge into a single massive galaxy, which could eventually evolve into something akin to the Milky Way.”

The astronomers used the combined power of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope and NASA’s Hubble Space Telescope to discover the far-flung trio of primitive galaxies nestled inside an enormous blob of primordial gas nearly 13 billion light-years from Earth.

Details of this study were published online on April 27 in the Publications of the Astronomical Society of Japan.

The Daily Galaxy via Kavli Institute

Image credit: 3-D map, NAOJ; Partial data supplied by: CFHT, SDSS; Einstein relativity graphic with thanks to drphysics.com

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