dark matter tagged posts

Photo shows PandaX, a xenon-based detector in China.
Credit: PandaX.

An international team of scientists that includes University of California, Riverside, physicist Hai-Bo Yu has imposed conditions on how dark matter may interact with ordinary matter – constraints that can help identify the elusive dark matter particle and detect it on Earth.

Dark matter – nonluminous material in space – is understood to constitute 85% of the matter in the universe. Unlike normal matter, it does not absorb, reflect, or emit light, making it difficult to detect. Physicists are certain dark matter exists, having inferred this existence from the gravitational effect dark matter has on visible matter. What they are less certain of is how dark matter interacts with ordinary matter – or even if it does.

In the s...

A view of the four central galaxies at the heart of cluster Abell 3827, at a broader range of wavelengths, including Hubble Space Telescope imaging in the ultraviolet (shown as blue), and Atacama Large Millimetre Array imaging at very long (sub-mm) wavelengths (shown as red contour lines). At these wavelengths, the foreground cluster becomes nearly transparent, enabling the background galaxy to be more clearly seen. It is now easier to identify how that background galaxy has been distorted. Credit: NASA/ESA/ESO/Richard Massey (Durham University)

Astronomers are back in the dark about what dark matter might be, after new observations showed the mysterious substance may not be interacting with forces other than gravity after all...

Conventional WIMP theories predict that dark matter particles rarely interact with one another, and only weakly with normal matter. Hitoshi Murayama of UC Berkeley and Yonit Hochberg of Hebrew University predict that dark matter SIMPs, comprised of a quark and an antiquark, would collide and interact strongly with one another, producing noticeable effects when the dark matter in galaxies collide. Credit: Kavli IPMU graphic

Colliding galaxies may be evidence in support of new candidate for universe’s elusive dark matter. The nature of dark matter remains elusive, with numerous experimental searches for WIMPs coming up empty-handed and MACHOs all but abandoned...

This is Michal Rawlik of ETH Zürich and Nicholas Ayres of Sussex University. Credit: University of Sussex

Scientists at the University of Sussex have disproved the existence of a specific type of axion – an important candidate ‘dark matter’ particle – across a wide range of its possible masses. The data were collected by an international consortium, the Neutron Electric Dipole Moment (nEDM) Collaboration, whose experiment is based at the Paul Scherrer Institut in Switzerland. Data were taken there and, earlier, at the Institut Laue-Langevin in Grenoble. Professor Philip Harris said: “Experts largely agree that a major portion of the mass in the universe consists of ‘dark matter’. Its nature, however, remains completely obscure...