How many Planck mass sized black holes would it take to account for dark matter? This seems such a simple solution for dark matter that you have to wonder why it's 2021 and they're only just considering it. The hypothesis is that when a black hole evaporates, it leaves behind a naked singularity with enough mass to be non-zero, but too little mass to evaporate.

That's after a talk about why dark matter probably isn't larger black holes.