Axion dark matter, solitons and the cusp–core problem

摘要: Self-gravitating bosonic fields can support stable and localised field configurations. For real fields, these solutions oscillate in time are known as oscillatons. The density profile is static, soliton. Such solitons should be ubiquitous models of axion dark matter, with the soliton characteristic mass size depending on some inverse power mass. Stable configurations non-relativistic axions studied numerically using Schr\"{o}dinger-Poisson system. This method, resulting profiles, reviewed. Using a scaling symmetry uncertainty principle, core related to central mass, $m_a$, universal way. Solitons have constant due pressure-support, unlike cuspy cold matter (CDM). One consequence this fact that composed ultra-light (ULAs) may resolve `cusp-core' problem CDM. In DM halos, thermodynamics will lead CDM-like Navarro-Frenk-White at large radii, small radii. Monte-Carlo techniques explore possible profiles form, fit stellar-kinematical data dwarf spheroidal galaxies performed. order for ULAs cusp-core (without recourse baryon feedback or other astrophysical effects) must satisfy $m_a<1.1\times 10^{-22}\text{ eV}$ 95\% C.L. On hand, $m_a\lesssim 1\times tension cosmological structure formation. An solution thus makes novel predictions future measurements epoch reionisation. seen evidence formation could soon impose \emph{Catch 22} axion/scalar DM, similar case warm DM.