An international collaboration has once again found that the local universe is expanding faster than the standard cosmological model predicts, possibly hinting at new physics.
One of the great debates in modern cosmology has now been further strengthened. An international collaboration of astronomers has published a particularly precise measurement of the expansion rate of the local universe, once again finding a value higher than that obtained from calculations based on the early universe. This means that the Hubble tension, the persistent gap between the two main methods of measuring the Hubble constant, is not going away—it is actually getting worse.
The new study, published on April 10, 2026 in the journal Astronomy & Astrophysics, carried out by the H0 Distance Network collaboration. The researchers reported a value of 73.50 plus or minus 0.81 kilometers per second per megaparsec, to an accuracy of just over one percent. This is one of the most precise direct estimates yet measured for the expansion rate of the local universe.
To understand the importance of the result, we need to go back to the heart of the controversy. There are currently two main ways to measure the expansion rate of the universe. One is based on direct measurements of distances to stars and galaxies in the relatively nearby universe. The other uses the cosmic microwave background radiation—the ancient light left over from the young universe—to calculate what the expansion rate should be today according to the standard cosmological model. If the model were complete and the measurements converged, both methods should give the same answer. In practice, this does not happen: local measurements tend to indicate a value of about 73, while calculations from the early universe usually give 67–68.
This numerical gap is not very large at first glance, but it is much larger than can be explained by ordinary statistical noise. It is therefore called the “Hubble tension,” and in recent years it has been considered one of the most vexing problems in cosmology. The question is whether it is a hidden error in one of the measurement methods, or a hint that something fundamental is missing in our understanding of the universe.
One of the key achievements of the new study is not just the value obtained, but the way in which it was obtained. Instead of relying on just one method, the researchers built a “distance network” that connects several overlapping methods for measuring distances in the local universe. Among other things, the measurement included Cepheid variables, red giant stars of known brightness, Type Ia supernovae, and certain types of galaxies. The idea is to create several independent paths to the same final result, thus checking whether the source of the discrepancy lies in the error of just one method. According to the study results, even when individual methods are removed from the calculation, the final value is almost unchanged. In other words, it is increasingly difficult to claim that the problem stems from a local glitch or bias in a single measurement method.
The researchers conclude that explanations that place all the blame on a single local error are becoming less likely. If the tension is real, it could point to physics beyond the accepted cosmological model. Such possibilities could include, for example, an incomplete description of dark energy, the existence of new particles, or the need for some change in our understanding of gravity on a cosmic scale. The study itself does not decide between these explanations, but it does narrow the room for maneuver for those hoping that the problem will go away with a small technical fix.
In addition to its scientific significance, the study also has community and methodological importance. It grew out of a broad effort by the astronomical community, which began with an international workshop held in Bern in March 2025, and brings together observations collected over decades into a single, transparent and accessible framework. In addition, the data and methods have been opened up for community use, so that future measurements can build on the same infrastructure and test whether the gap will close or actually widen.
If this is indeed a sign that the Standard Model of cosmology is incomplete, then the “Hubble Tension” is not just a dispute over a number. It may be one of the most important clues that the universe still holds some very fundamental secrets to itself.
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