In the world of cosmology, the rate at which the universe is expanding remains a perplexing mystery. The standard model of cosmology, known as Lambda-cold dark matter (ΛCDM), attempts to explain this phenomenon based on observations of the cosmic microwave background (CMB) left over from the Big Bang. However, recent measurements have disputed the predicted expansion rate, leading to what scientists refer to as the Hubble tension. In a new study, researchers propose that we live in a massive void in space with below-average density, which could explain the discrepancies in measurements. This idea challenges the standard model and introduces the concept of Modified Newtonian Dynamics (MOND), which suggests that gravity behaves differently in weak gravitational fields. The study’s findings align well with observations of the velocity of matter in different regions, known as the bulk flow, and provide a potential solution to the Hubble tension. Despite popular alternative explanations, such as more accurate measurements or slight adjustments to the early universe’s expansion history, this study’s findings challenge these notions. The existence of a deep and extensive local void, along with the fast observed bulk flows, suggests that the growth of structure in the universe is faster than predicted by the standard model. This implies that our
https://phys.org/news/2023-12-giant-void-puzzle-universe-expansion.html