Dark Matter Eludes Observers

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Dwarf Galaxies Dim Hopes of Dark Matter | Quanta Magazine

Once again, a shadow of a signal that scientists hoped would amplify into conclusive evidence of dark matter has instead flatlined, repeating a maddening refrain in the search for the invisible, omnipresent particles.
The Fermi Large Area Telescope (LAT) failed to detect the glow of gamma rays emitted by annihilating dark matter in miniature “dwarf” galaxies that orbit the Milky Way, scientists reported Friday at a meeting in Nagoya, Japan. The hint of such a glow showed up in a Fermi analysis last year, but the statistical bump disappeared as more data accumulated.

LUX dark-matter search comes up empty - physicsworld.com
Dark Matter Still Hiding: Latest Experimental Sweep Comes Up Empty - Scientific American 

The Large Underground Xenon (LUX) dark-matter detector at the Sanford Underground Research Facility in the US has failed to find any evidence for dark matter in the first three months of its operation. One of the world's most sensitive dark-matter detectors, LUX has managed to put more stringent limits on what dark matter could be. In particular, the preliminary results suggest that previous hints of low-mass dark-matter particles reported by some other experiments might not be credible.

Could dark matter be the modern "Luminiferous Aether" - how sensitive will experiments have to be to get a Michelson Morley result and a new Einstein comes along?

Dark Energy and Beyond-jain.pdf

2/19/14
Bhuvnesh Jain (U. Penn)

The discovery that our universe is accelerating poses fascinating challenges for physics and astronomy. Vacuum energy, more generally called dark energy, is a possible explanation for the observed cosmic acceleration. Modifications to Einstein's general relativity are being explored as alternatives to dark energy. I will describe the theoretical motivations and experimental tests of gravity theories and other effects involving dark sector couplings. On large scales, they require a different take on cosmological observations such as gravitational lensing and large-scale structure in the universe. On much smaller scales the new tests of gravity use pulsating stars, rotating disk galaxies and other astronomical phenomena. I will describe how these diverse observations are being used to look "beyond dark energy".