dark matter tagged posts

The weak lensing surveys such as HSC prefer a slightly less clumpy Universe (left) than that predicted by Planck (right). The pictures show the slight but noticeable difference as expected from large computer simulations.
Credit: Hyper Suprime-Cam Survey

An international group of researchers, including Carnegie Mellon University’s Rachel Mandelbaum, has released the deepest wide field map of the 3D distribution of matter in the universe ever made and increased the precision of constraints for dark energy with the Hyper Suprime-Cam survey (HSC).

The present-day universe is a pretty lumpy place...

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...