Researchers have solved a "cosmological conundrum" by measuring the mass of neutrinos.
In doing this a research team solved a pressing issue having to do with the current standard model of cosmology, a University of Manchester news release reported.
The team analyzed observations of the Big Bang and the curvature of space-time to measure the mass of these "ghostly sub-atomic particles."
Planck spacecraft observations of the Cosmic Microwave Background (CMB) (the glow left over from the Big Bang) disputed the results of past measurements.
This ancient light allows researchers to determine cosmological parameters such as the age of the universe itself; but past researchers have found inconsistencies when factors such as galactic observations are taken into account.
"We observe fewer galaxy clusters than we would expect from the Planck results and there is a weaker signal from gravitational lensing of galaxies than the CMB would suggest," Professor Richard Battye, from The University of Manchester School of Physics and Astronomy, said in the news release. "A possible way of resolving this discrepancy is for neutrinos to have mass. The effect of these massive neutrinos would be to suppress the growth of dense structures that lead to the formation of clusters of galaxies."
Neutrinos are difficult to study because they have very weak reactions with other matter. In the past scientists thought they lacked a mass altogether, but particle physics experiments have suggested otherwise.
Neutrinos are believed to come in several different types, called "flavors," and the sum of the masses of them is only about 0.06 eV (" less than a billionth of the mass of a proton").
Using data from gravitational lensing observations the researchers determined the discrepancies could be resolved if the massive neutrinos were included in the common cosmological model. They determined the sum of the mass of three-flavored neutrinos was 0.320 +/- 0.081 eV.
"If this result is borne out by further analysis, it not only adds significantly to our understanding of the sub-atomic world studied by particle physicists, but it would also be an important extension to the standard model of cosmology which has been developed over the last decade," Doctor Adam Moss, from the University of Nottingham said in the news release.
