One of the biggest mysteries in cosmology is the Hubble tension, the discrepancy between different measurements of the universe's expansion rate. A new study has found that the gravitational pull of the Laniakea Supercluster, our home supercluster, makes the Hubble tension even worse than previously thought.
The study, published on the arXiv preprint server, found that the gravitational influence of the Laniakea Supercluster biases our observations of cosmic expansion by about 2%–3%. However, this bias is in the wrong direction, meaning that it makes the Hubble tension seem smaller than it actually is.
When the researchers accounted for the Laniakea bias, they found that the Hubble tension was 2%–3% greater than previously thought. This means that the discrepancy between different measurements of the universe's expansion rate is even more difficult to explain.
The Hubble tension is a major challenge to our current understanding of the universe. It could be a sign that our cosmological model is incorrect, or it could be a sign of new physics that we don't yet understand.
The new study suggests that the Laniakea Supercluster may be playing a role in the Hubble tension. However, more research is needed to confirm this and to understand how the supercluster's gravitational pull is affecting our observations.
Journal Information: L. Giani et al, An effective description of Laniakea and its backreaction: Impact on Cosmology and the local determination of the Hubble constant, arXiv (2023). DOI: 10.48550/arxiv.2311.00215