Is the Universe decelerating? #shorts

From the creator

Instead they argue that dark energy is changing, and that the Universe is decelerating. These models of the Universe where the accelerated expansion rate is changing have been coming up a lot lately, the DESI survey for example have found evidence for it looking at the large scale structure of the Universe, which I’ve covered on my channel before. But they concluded that the acceleration rate is slowing down, but it's still accelerating. A result Son and collaborators claim is because the supernova data they added had this age-bias. They claim that the younger galaxy-fainter supernova effect leads to a 0.16 bias in the brightness of the supernova measured, and you end up with a statistically significant difference with what’s predicted by our current best model of the Universe. So here’s the key plot - on the horizontal axis you’ve got age of the Universe, and on the vertical the rate of acceleration of the Universe - our best current model is shown by the black line, very clearly accelerating today. Then you’ve got three other lines, all of which use the DESI large scale structure data, that’s independent of the supernovae. The green shows the result from the original DESI paper, combining the large scale structure with supernova data uncorrected for age bias, which gives a slower accelerating Universe, the blue line if you don’t include any supernova data at all, and the red line the supernova data corrected for the age-bias by Son and collaborators, both of which give

Published 2026-07-06 · Watch on YouTube ↗
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