Speaker
Description
The small-scale distribution of dark matter (DM) remains a key challenge in modern cosmology. While the ΛCDM paradigm successfully describes large-scale structure formation, tensions persist at galactic and sub-galactic scales, particularly in the abundance and internal structure of dwarf galaxies. Warm dark matter (WDM) has emerged as a compelling alternative to cold dark matter (CDM), as its suppressed small-scale power spectrum modifies the formation and evolution of low-mass galaxies.
In my talk, I will discuss, using high-resolution hydrodynamical simulations from the DREAMS project (DaRk mattEr with AI and siMulationS), a procedure to constrain the mass of WDM particles, by examining its impact on galactic scaling relations and number density of low-mass galaxies.
I will show that the number of galaxies with stellar masses M_{*} ≲ 10^{8}M_{☉} is sensitive to the WDM particle mass. As the WDM mass decreases, the number of dwarf galaxies predicted in simulations drops. This effect emerges clearly in Milky Way zoom-in simulations, where the higher resolution allows us to probe lower-mass galaxies.
By comparing simulated scaling relations —such as size, dark matter content, dark matter fraction, and total mass versus stellar mass in galaxies—with observational datasets, such as SPARC and Local Volume dwarf galaxies, I will assess degeneracies between WDM effects and baryonic feedback. Using a statistical approach based on χ² minimization, I will demonstrate how the WDM particle mass influences both the number and structural properties of dwarf galaxies.
Looking ahead, the vast number of dwarf galaxies discovered in wide-field surveys, such as the Euclid Wide Survey, will strengthen the statistical power needed to test these predictions.