Slice of the universe's largest 3D map showing the fundamental structure of matter
A collaboration between Leah Raman and DESI. Custom colormap package with cmastro
The largest 3D map of the universe ever created offers hints about the evolution of the universe and suggests we may be wrong about the behavior of dark energy, which makes up most of the universe. I am. This mysterious power may weaken over time.
“If it can be maintained, this is a very big deal,” he says Adam Rees Johns Hopkins University in Maryland discovered the first evidence of dark energy 25 years ago. That's because the standard model of cosmology, called the lambda CDM, suggests that the intensity of dark energy should not change over time.
Dark energy is thought to cause the accelerated expansion of the universe. If it is not static, it could also have major implications for our ideas about the universe's beginning, its size, and ultimate fate. Mr. Reese, who was not involved in the new work, said the impact was that “we… [our understanding of] “Gravity and Field”.
This strange finding comes from the Dark Energy Spectroscopy Instrument (DESI) in Arizona, where even DESI collaborators say data suggests dark energy may be weakening in recent times. I don't really know what to make of that fact. A DESI spokesperson said: “Whether this is interesting or not, this is all we have been talking about in this collaboration for months.” Kyle Dawson at the University of Utah.
DESI researchers investigated the strength of dark energy by measuring the large-scale structure and distribution of galaxies in the universe, revealing how the universe has expanded over time. The researchers then combined this information with three sets of data about supernovae. Supernovae act as so-called “standard candles” that determine the distance to cosmic objects thanks to their predictable brightness.
Surprisingly, each of the three supernova samples gave a different answer to the changing rate of expansion of the universe over time. All three suggest that the influence of dark energy may have declined in recent years, but the strength of these suggestions varies, so researchers wonder how to interpret the data. I don't really understand.
“Two of the supernova samples don't match each other, but they are very similar,” Dawson said. “We don't know which one is correct. The truth may lie somewhere in between, but the real difference seems to be in the method.” [the supernova researchers] We evaluated the data. ”
Model discrepancy is indicated by a coefficient called sigma. Sigma measures the likelihood that similar collisions will occur by chance when the models do not match each other. “About 3 sigma is the level at which we typically sit and pay attention and call it a 'sign' of something,” Reese says. Values lower than that are usually not of particular interest to researchers. It would be too likely a simple coincidence.
The discrepancies between the lambda CDM and combined supernova and DESI measurements ranged from 2.5 sigma to 3.9 sigma. “Both opinions are true. There's enough tension and it's interesting. And there's not enough tension to say that something is definitely there,” says Dawson.
Dark energy makes up nearly 70 percent of the universe, so errors in our understanding of its properties can have far-reaching implications for physics. However, more precise measurements will be needed in the coming years to prove whether the error really exists.
“if [this is] “Certainly, this is the first real clue we've had about the nature of dark energy in 25 years,” says Rees.
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Source: www.newscientist.com
