Enormous galaxy cluster appears to defy cosmological principle

Washington Post : The cosmological principle is the idea that at large enough scales there shouldn’t be any definable structures to the material present in the universe. A collection of galaxies 7 billion light-years away is just the most recent structure that appears to violate that principle. The collection, which appears to be shaped as a ring 5.6 billion light-years across, was identified from observations of nine gamma-ray bursts. The similarities of the bursts and their nearness suggests that they originated from a single intergalactic feature. Lajos Balazs of the Konkoly Observatory in Budapest, Hungary, and his colleagues say that there is a less than 1 in 20 000 chance that the arrangement is random. Researchers had previously spotted a cluster nearly 10 billion light-years across, but the evidence for that structure isn’t as strong. However, the generally accepted upper limit for the size of gravitationally bound structures is 1.2 billion light-years.