Warm Dark Matter Astrophysics in Agreement with Observations and keV Sterile Neutrinos: Synthesis of Highlights and Conclusions of the Chalonge -de Vega Meudon Workshop 2016 . In Memoriam Héctor J. de Vega

Overview & Synopsis

The mass distribution observed in galaxies is found to be incompatible with the CDM predictions , falsifies the baryonically fine-tuned CDM scenarios and leads to keV Warm Dark Matter (WDM). WDM is a hot topic in galaxies and cosmology and implies novelties in the astrophysical, cosmological, particle and nuclear physics context. WDM research is progressing fast because it essentially works naturally reproducing the observations at all scales. A Turning Point operated recently in the Dark Matter research: Warm Dark Matter emerged impressively over Cold Dark Matter (CDM) as the leading Dark Matter candidate. WDM solves naturally the problems of CDM and CDM + baryons. (ΛWDM) provides the same successful large-scale results and CMB results as ΛCDM and agrees with the observations at the galactic and small scales as well. The Chalonge-de Vega Workshop 'Warm Dark Matter in Astrophysics in Agreement with Observations and keV Sterile Neutrinos' addressed the last WDM achievements including its distribution function and equation of state (The Eddington like approach to galaxies), the quantum mechanical framework to galaxy structure reproducing in particular the observed galaxy cores and their sizes, and the properties of dwarf galaxies. This workshop summary puts together astrophysical, cosmological, particle and nuclear WDM, astronomical observations, theory and WDM analytical and numerical frameworks, which reproduce the observations. The Workshop addressed the exciting ongoing theoretical and experimental developments in the search for the leading WDM particle candidate: keV sterile neutrinos. The recent impact of WDM astrophysics, its signatures and constraints with high redshift galaxies, clusters, cosmic recombination, 21 cm line, with or for the JWST, HST, SKA, X-ray astronomy and gravitational lensing were presented. News from KATRIN, ECHo, and ASTRO-H were presented by members of the respective collaborations. The present document represents a synthesis report of the main results.