Ultralight scalars as cosmological dark matter

Many aspects of the large-scale structure of the Universe can be described successfully using cosmological models in which $27\ifmmode\pm\else\textpm\fi{}1%$ of the critical mass-energy density consists of cold dark matter (CDM). However, few---if any---of the predictions of CDM models have been successful on scales of $\ensuremath{\sim}10\text{ }\text{ }\mathrm{kpc}$ or less. This lack of success is usually explained by the difficulty of modeling baryonic physics (star formation, supernova and black-hole feedback, etc.). An intriguing alternative to CDM is that the dark matter is an extremely light ($m\ensuremath{\sim}{10}^{\ensuremath{-}22}\text{ }\text{ }\mathrm{eV}$) boson having a de Broglie wavelength…

• NS
  National Science Foundation

  Awards: PHY-1606531, 1406166, AST-1406166
• UD
  U.S. Department of Energy

  Award: DE-SC0011941
• NA
  National Aeronautics and Space Administration

  Awards: NXX16AB27G, NNX14AM24G