Reanalysing large-scale structure using an updated gamma-ray burst spatial density approach

TL;DR

This study reanalyzes gamma-ray burst distributions to test large-scale structure and isotropy, finding only two significant deviations that do not challenge the cosmological principle.

Contribution

Introduces a new 3D sphere-based method for analyzing gamma-ray burst clustering and large-scale structure in the universe.

Findings

Detected a large structure in the Northern hemisphere (Hercules-Corona Borealis Great Wall)

Found a small cluster of 4-5 GRBs in the Southern hemisphere

Method did not find other significant overdensities in GRB distribution

Abstract

In the past few decades, large universal structures have been found that challenge the homogeneity and isotropy expected in standard cosmological models. This study examines burst clustering in both galactic hemispheres using a recently developed methodology, using spheres in 3D space for testing regularities. Using our new method in both hemisphere we find only one deviation from isotropy. A small one in the Southern and a huge one in the Northern hemisphere. This itself suggests that the two deviations do not likely to come from statistical fluctuation. The northern huge group contains app. 125 gamma-ray bursts (GRBs) corresponds with the so - called Hercules-Corona Borealis Great Wall. The southern group contains 4-5 GRBs locating very close to each other. Two of them (GRB050822 and GRB050318) are close not just in redshift and the angular position but they are very close in observing time (5 months). We concluded that the third important result of this work that this method could not find other overdensity deviation from homogeneity in the GRBs spatial distribution. We have shown that the large-scale density increase in the spatial distribution of gamma-ray bursts does not necessarily violate the cosmological principle.