Astronomy
The Structure of Dark Matter Halos from Numerical Simulations
Quick fact
Numerical simulations reveal that dark matter halos have a universal density profile, known as the NFW profile, which predicts a steep 'cuspy' center, yet some observed galaxies show a flat 'core' that challenges this.
Why this is interesting
The universe is mostly filled with an invisible substance that holds galaxies together, and we've never directly seen it. How can we possibly know what shape it takes?