Ultra-Light Scalar Field Dark Matter

Mar 13, 2018 - 12:15 pm to 1:15 pm

Campus, PAB 232

Ethan Nadler

ΛCDM cosmology is remarkably consistent with observations of the Universe on large scales. However, neither direct nor indirect detection experiments have yet found convincing evidence for weakly interacting cold dark matter particles; in addition, there are possible tensions between predictions derived from cold dark matter simulations and cosmological observations in the dwarf galaxy regime. This situation had led to an interest in ultra-light scalar field dark matter (SFDM), which consists of extremely light (m ~ 10-22 eV) scalar particles. In this talk, we discuss the theory underlying SFDM, including why it is natural to introduce ultra-light scalar fields and how they evolve in a cosmological setting. We describe how SFDM can reproduce the large-scale successes of cold dark matter while alleviating some of its small-scale challenges, and we cover several astrophysical effects associated with SFDM. We conclude by summarizing the main sources of constraints on SFDM and the status of these models.