EurekAlert 8-Apr-2020
Study by the Universities of Bonn and Harvard questions a fundamental principle of cosmologyNo matter where we look, the same rules apply everywhere in space: countless calculations of astrophysics are based on this basic principle. A recent study by the Universities of Bonn and Harvard, however, has thrown this principle into question. Should the measured values be confirmed, this would toss many assumptions about the properties of the universe overboard. The results are published in the journal Astronomy & Astrophysics, but are already available online.
Since the big bang, the universe has swollen like a freshly formed raisin roll put in a warm place to rise. Until recently, it was thought that this increase in size was occurring evenly in all directions, as with a good yeast dough. Astrophysicists call this "isotropy". Many calculations on the fundamental properties of the universe are based on this assumption. It is possible that they are all wrong - or at least, inaccurate - thanks to compelling observations and analyses of the scientists from the Universities of Bonn and Harvard.-------
The third possibility is the most serious: What if the universe is not isotropic at all? What if - metaphorically speaking - the yeast in the galactic raisin roll is so unevenly distributed that it quickly bulges in some places while it hardly grows at all in other regions? Such an anisotropy could, for example, result from the properties of the mysterious "dark energy", which acts as an additional driving force for the expansion of the universe. However, a theory is still missing that would make the behavior of the Dark Energy consistent with the observations. "If we succeed in developing such a theory, it could greatly accelerate the search for the exact nature of this form of energy," Migkas is certain.
The current study is based on data from more than 800 galaxy clusters, 300 of which were analysed by the authors. The remaining clusters come from previously published studies. The analysis of the X-ray data alone was so demanding that it took several months. The new satellite-based eROSITA X-ray telescope is expected to record several thousand more galaxy clusters in the coming years. At the latest then it will become clear whether the isotropy hypothesis really has to be abandoned.
More:
https://www.eurekalert.org/pub_releases/2020-04/uob-dab040820.php
