Using data from NSF’s Atacama Cosmology Telescope, astronomers have produced the most detailed map of dark matter distributed across one quarter of the sky. Their work provides further support to Einstein’s theory of general relativity, which has been the foundation of the Standard Model of cosmology for more than a century.
Although dark matter makes up a large chunk of the Universe, approximately 85%, it has remained hard to detect because dark matter does not interact with light or other forms of electromagnetic radiation.
Scientists believe dark matter may only interact with gravity.
To track dark matter down, Stony Brook University astronomer Neelima Sehgal and more than 160 astronomers worldwide have built and gathered data from NSF’s Atacama Cosmology Telescope in the high Chilean Andes.
The astronomers focused the Cosmic Microwave Background (CMB) radiation — light emanating from the dawn of the Universe’s formation, the Big Bang, when the Universe was only 380,000 years old.
They tracked how the gravitational pull of large, heavy structures including dark matter warps the CMB on its 14-billion-year journey to us, like how a magnifying glass bends light as it passes through its lens. This phenomenon is called gravitational lensing.
“The ACT result showcases the precision that can be obtained with measurements of the gravitational lensing of the microwave background, as well as the promise of future more sensitive CMB experiments in terms of furthering our understanding of the physics of the Universe,” Dr. Sehgal said.
The work further supports Einstein’s theory about how massive structures grow and bend light, with a test that spans the entire age of the Universe.
“We’ve made a new mass map using distortions of light left over from the Big Bang,” said Dr. Mathew Madhavacheril, an astronomer at the University of Pennsylvania.
“Remarkably, it provides measurements that show that both the ‘lumpiness’ of the Universe, and the…
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