galaxy cluster

An illustration of gravity. Illustration: depositphotos.com

Could gravity exist without mass, thus reducing the need for the hypothetical dark matter

Scientists say that circular systems of topological structural defects common throughout the universe may be the source of the "excess" gravity needed to hold a galaxy or cluster together.
SMACS galaxy cluster. This image of the galaxy cluster SMACS 0723 and its surroundings was the first image released from the James Webb Space Telescope in July 2022. The five close-up images are about 19,000 light-years across and show galaxies as they appeared about 13 billion years ago. Careful analysis of these galaxies reveals that if we cannot resolve the discrepancy, we may greatly underestimate the total mass of its stars. Image credit: NASA, ESA, CSA, STScI / Giménez-Arteaga et al. (2023), Peter Lorsen (Cosmic Dawn Center).

Astronomers are surprised by the unexpected size of galaxies in the early universe photographed by the James Webb Space Telescope

The first findings from the James Webb space telescope hinted at galaxies so early and massive that they are somewhat inconsistent with our understanding of the formation of structure in the universe. A new study tries to deal with the contradictions