Ohio State University | 2016 Aug 11
A lot of information contained in cosmic voids, study suggests
[img3="This simulation of the large-scale structure of the universe reveals the cosmic web of galaxies and the vast, empty regions known as voids. Image by Nico Hamaus, Universitäts-Sternwarte München, courtesy of The Ohio State University."]https://news.osu.edu/assets/image-cache ... 24d4b5.jpg[/img3][hr][/hr]Researchers who are looking for new ways to probe the nature of gravity and dark energy in the universe have adopted a new strategy: looking at what’s not there.
In a paper to appear in upcoming issue of Physical Review Letters, the international team of astronomers reports that they were able to achieve four times better precision in measurements of how the universe’s visible matter is clustered together by studying the empty spaces in between.
Paul Sutter, study co-author and staff researcher at The Ohio State University, said that the new measurements can help bring astronomers closer to testing Einstein’s general theory of relativity, which describes how gravity works.
Sutter likened the new technique to “learning more about Swiss cheese by studying the holes,” and offered another analogy to explain why astronomers would be interested in the voids of space.
“Voids are empty. They’re boring, right? Galaxies are like the cities of the universe, full of bright lights and activity, and voids are like the miles and miles of quiet farmland in between,” Sutter explained.
“But we’re looking for bits of evidence that general relativity might be wrong, and it turns out that all the activity in galaxies makes those tiny effects harder to see. It’s easier to pick up on effects in the voids, where there’s less distraction—like it’s easier to spot the glimmer of a firefly in a dark cornfield than in a lit-up city bustling with nightlife.”
The voids, he pointed out, are only empty in the sense that they contain no normal matter. They are, in fact, full of invisible dark energy, which is causing the expansion of the universe to accelerate. ...
Constraints on Cosmology and Gravity from the Dynamics of Voids - Nico Hamaus et al
- arXiv.org > astro-ph > arXiv:1602.01784 > 04 Feb 2016