Dark matter in small galaxies
Start with a dwarf galaxy’s rotation speed. Build the cold cusp, remove small-scale power with warm and fuzzy dark matter, make cores with waves, collisions and gas, then recompute the benchmarks and read a published satellite census.
L1 · Concept
Can different dark matter leave similar small galaxies?
Yes. Waves, collisions and gas can all flatten a dwarf galaxy's centre, so a core alone cannot name the dark matter. Halo numbers and trends help.
L1 · Chapter
How a cusp or a core shapes a rotation curve
Build a cold dark matter halo from the NFW profile, compute its enclosed mass and circular speed, and see how a flat core lowers the inner rotation curve.
L2 · Chapter
How warm and fuzzy dark matter erase small ripples
Read a transfer function, turn a half-mode scale into a halo mass, and compute how much warm or fuzzy dark matter thins out small halos.
L3 · Chapter
Three ways to make a dark matter core
Derive the fuzzy soliton, the self-interacting isothermal core and the feedback core in one dwarf halo, then compare how each core changes with halo mass.
L3 · Method
Recompute the warm cutoff, the fuzzy cutoff and the soliton
Check three dark matter fitting formulas against a frozen CLASS grid, a growth equation and an exact soliton, with scripts, outputs and failure cases.
L3 · Paper guide
Reading the Milky Way satellite limits on warm and fuzzy dark matter
A figure-by-figure guide to Nadler et al. 2021: how satellite counts give warm and fuzzy dark matter limits, and where those limits are soft.