Understanding Dwarf Galaxies in Order to Understand Dark Matter

Abstract

Much progress has been made in recent years by the galaxy simulation community in making realistic galaxies, mostly by more accurately capturing the effects of baryons on the structural evolution of dark matter halos at high resolutions. This progress has altered theoretical expectations for galaxy evolution within a Cold Dark Matter (CDM) model, reconciling many earlier discrepancies between theory and observations. Despite this reconciliation, CDM may not be an accurate model for our Universe. Much more work must be done to understand the predictions for galaxy formation within alternative dark matter models.

Testing the Relationship Between Bursty Star Formation and Size Fluctuations of Local Dwarf Galaxies

“…Dwarf galaxies, with stellar masses 10 9 M , are known to challenge CDM predictions on small scales (Brooks 2019). It has long been recognized that the observed dark matter halos of dwarf galaxies exhibit a different core density profile (Flores & Primack 1994;Moore 1994) than the predicted dark matter-only Navarro-Frenk-White (NFW) (Navarro et al 1997) profile.…”

Ultralight DM bosons with an axion-like potential: scale-dependent constraints revisited

“…Although the CDM model is so far in good agreement with most of the cosmological observations, DM nature is still a mystery. It is well known that there are some differences at small scales between astrophysical observations and numerical simulations based on CDM [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. These differences may be due to the lack of information about astrophysical processes of galactic substructures and baryonic physics, but they could also be a manifestation of the still unknown properties of the DM field.…”

Snowmass2021 Cosmic Frontier White Paper: Prospects for obtaining Dark Matter Constraints with DESI

“…The vast majority of constraints currently available on the nature of dark matter come from comparisons between observations and cosmological simulations with ΛCDM, although there have been significant advances in the past decade on simulations with other types of DM (for a review see CF3-solicited white paper by Banerjee, Boddy et al). Although there are clearly identifiable differences between the predictions from different types of dark matter, it has become increasingly clear over the past decade that it is much more difficult to distinguish between different DM scenarios when baryonic effects are considered [196]. However, the next decade is expected to witness a substantial increase in the spatial and mass resolution of cosmological hydrodynamical simulations that will undoubtedly lead to significant improvements in the representation of DM halos both at high redshift and in the local Universe.…”