CrazyNeutrino said:
Dark matter may be smoother than expected
Analysis of a giant new galaxy survey suggests that dark matter may be less dense and more smoothly distributed throughout space than previously thought. An international team used data from the Kilo Degree Survey (KiDS) to study how the light from about 15 million distant galaxies was affected by the gravitational influence of matter on the largest scales in the universe.
More…
Acronym KiDS. I didn’t see that coming.
“VLT Survey Telescope at ESO’s Paranal Observatory in Chile”. “area of around 2200 times the size of the full Moon. This corresponds to about 450 square degrees, or a little more than 1% of the entire sky.”.
Technical article https://arxiv.org/pdf/1606.05338.pdf
“The current ‘standard cosmological model’ ties together a diverse set of properties of the observable Universe. Most importantly, it describes the statistics of anisotropies in the cosmic microwave background radiation, the Hubble diagram of supernovae of type Ia, big bang nucleosynthesis, and galaxy clustering. It successfully predicts key aspects of the observed large-scale structure, from baryonic acoustic oscillations on the largest scales down to Mpc-scale galaxy clustering and associated inflow velocities. It is also proving to be a successful paradigm for galaxy formation and evolution theories.”
But it doesn’t agree with these new results. The new results agree with the 9 year WMAP results, but not with the 2015 Planck results. I wouldn’t worry too much, the standard deviation for the new results is very much greater than for the Planck 2015 results.
Other technical article from this year on measuring cosmological parameters using KiDS-450 https://arxiv.org/pdf/1610.04606.pdf
“We test extensions to the standard cosmological model with weak gravitational lensing tomography using 450 deg2 of imaging data from the Kilo Degree Survey (KiDS). In these extended cosmologies, which include massive neutrinos, nonzero curvature, evolving dark energy, modified gravity, and running of the scalar spectral index, we also examine the discordance between KiDS and cosmic microwave background measurements from Planck.”
“The only extended cosmology that simultaneously alleviates the discordance with Planck and is at least moderately favored by the data includes evolving dark energy with a time-dependent equation of state”. This reduces the disagreement between Planck and KiDS from 2.3 sigma to 1 sigma.
Not that much improvement, but worth watching.