Joel Primack

ΛCDM cosmology: successes, challenges, possible detection of dark matter, opportunities for progress

Abstract: The Cosmic Background Radiation observed by the WMAP and Planck satellites is very well described by the now-standard ΛCDM cosmology. The WMAP and Planck cosmological parameters are somewhat different from each other, and I will briefly comment on this and describe our new simulations based on the Planck parameters. Planck paper XX says that their Sunyaev-Zel'dovich cluster observations are somewhat discrepant with the Planck cosmological parameters, but I will explain why there is probably no inconsistency. The "Cusp-Core" and "Too Big to Fail" dwarf galaxy challenges to ΛCDM appear likely to be resolved by properly including the effect of stellar feedback, although both observation and theory need to be improved. I will describe the Assembling Galaxies of Resolved Anatomy (AGORA) project, which aims to compare high-resolution hydrodynamic galaxy simulations and raise the level of such simulations. Preliminary analyses of X-ray data have been claimed to favor 7 keV sterile neutrinos as the dark matter, but if the sterile neutrinos are Dodelson-Widrow, they are probably too warm to be the dark matter. New analyses of Fermi satellite gamma ray data are claimed to favor ~35 GeV weakly interacting massive particles (WIMPs) as the dark matter; if true, there should be additional observational and/or experimental confirmations soon. I will finally discuss other opportunities for dark matter progress in the near future.