Is dark matter composed of sterile neutrinos?

Jan 15, 2007 feature

“If you ask the question, ‘What is the content of the universe?’ the answer is not so simple,” says Mikhail Shaposhnikov, a scientist associated with the École Polytechnique Fédérale de Lausanne and CERN, both in Switzerland. Shaposhnikov explains to that only seven or eight percent of the universe is composed of what we term “regular” matter.

About 70 percent is dark energy, and around 22 percent of the universe is made up of dark matter. “Dark matter makes up a substantial part of the universe,” Shaposhnikov says. “Knowing what it is would answer a crucial question about the universe as a whole.”

Shaposhnikov and a team of scientists from Switzerland and France have a suggestion for how to determine whether or not sterile neutrinos are the main particles that make up dark matter. “Nobody knows what dark matter is made of,” he says. “Some scientists say that it is related to supersymmetry and believe it is made from WIMPs.

Others put forth axions as the most promising dark matter candidate. We think that sterile neutrinos make a good candidate.” Shaposhnikov and his colleagues have a specific suggestion for finding out whether sterile neutrinos are the particles that make up dark matter. Their ideas are found in a Letter titled “Strategy for Searching for a Dark Matter Sterile Neutrino” in Physical Review Letters.

In order to test the idea of sterile neutrinos as dark matter, Shaposhnikov and his co-authors suggest that a strategy that uses the particular astrophysical objects, as well as adequate detection instruments, be implemented. Their strategy is based the fact that, while sterile neutrinos do last a long time, they are unstable. “Sterile neutrinos can decay into ordinary neutrinos and photons,” explains Shaposhnikov, “and photons from sterile neutrino decays can be seen at X-ray laboratories in Space.” This is what the team says needs to be detected.

“First,” Shaposhnikov says, “we would need to find the astrophysical objects to look at. Dwarf galaxies are good choices.” He points out that the signals that come from dark matter decay are weak, and easily hidden. But dwarf galaxies have a high ratio of dark matter to “regular” matter. “This means that there are fewer sources for the weak dark matter signals to hid behind.”

Next, better X-ray instruments are needed to analyze the information. “The current X-ray telescopes were not constructed to find dark matter,” says Shaposhnikov. “They show us very interesting things, and have good angular resolution. But they do not have the spectrometer needed to find dark matter.” He says that sterile neutrino decays produce a monochromatic line that is difficult for current instruments to detect. “We need devices with energy resolution of one or two orders of magnitude better than we have.”

Unfortunately, such a detector is not in the works. “Cosmic research is very expensive, so there are no concrete plans to make such a high resolution spectrometer that can scan a wide range of energies. But, we are trying to convince our experimental colleagues that this is a good direction to go in,” Shaposhnikov says. “There are programs that search for dark matter decays, but in order to make real progress, something better is needed.”

By Miranda Marquit, Copyright 2006
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of

Explore further: The birth of topological spintronics

add to favorites email to friend print save as pdf

Related Stories

Mysterious X-ray signal intrigues astronomers

Jun 24, 2014

( —A mysterious X-ray signal has been found in a detailed study of galaxy clusters using NASA's Chandra X-ray Observatory and ESA's XMM-Newton. One intriguing possibility is that the X-rays are ...

Scientists announce top 10 new species for 2014 (w/ Video)

May 22, 2014

An appealing carnivorous mammal, a 12-meter-tall tree that has been hiding in plain sight and a sea anemone that lives under an Antarctic glacier are among the species identified by the SUNY College of Environmental ...

Glimmer of light in the search for dark matter

Feb 27, 2014

The Leiden astrophysicist Alexey Boyarsky and his fellow researchers may have identified a trace of dark matter that could signify a new particle: the sterile neutrino. A research group in Harvard reported ...

Sterile neutrinos and the search for warm dark matter

Sep 01, 2006

Matteo Viel, a research fellow at the Institute of Astronomy in Cambridge, England, believes that particle physics and cosmology could be more compatible as scientists work toward understanding the origins ...

Recommended for you

IHEP in China has ambitions for Higgs factory

6 hours ago

Who will lay claim to having the world's largest particle smasher?. Could China become the collider capital of the world? Questions tease answers, following a news story in Nature on Tuesday. Proposals for ...

The physics of lead guitar playing

7 hours ago

String bends, tapping, vibrato and whammy bars are all techniques that add to the distinctiveness of a lead guitarist's sound, whether it's Clapton, Hendrix, or BB King.

The birth of topological spintronics

8 hours ago

The discovery of a new material combination that could lead to a more efficient approach to computer memory and logic will be described in the journal Nature on July 24, 2014. The research, led by Penn S ...

The electric slide dance of DNA knots

11 hours ago

DNA has the nasty habit of getting tangled and forming knots. Scientists study these knots to understand their function and learn how to disentangle them (e.g. useful for gene sequencing techniques). Cristian ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) May 02, 2009
An attempt has been made, in the following paper presented in Russia in 2008, to explain what is Dark Matter and Dark radiation based on my experimental findings:

M.A. Padmanabha Rao, Invited Paper. Solar x-rays, gamma rays, and electrons cause EUV by a previously unknown atomic phenomenon, in: Vladimir V.Zaitsev (Ed.),Proceedings of the 7th International Conference, Human Ecology and Nature (HEN2008), Moscow-Ples, Russia, Moscow Scientific and industrial Association %u201CRadon%u201D, 2008, 45-50 http://www.angelf...ion.html