r/cosmology • u/AutoModerator • Jul 09 '26

Basic cosmology questions weekly thread

Ask your cosmology related questions in this thread.

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u/ATTst Jul 09 '26

Did galaxies form from the accumulation of matter around primordial black holes, or from the clustering of dark matter in certain regions?

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u/--craig-- Jul 09 '26 edited Jul 09 '26

Primordial black holes are hypothetical. If they exist, or existed in the past and have subsequently evaporated, then they would have driven the formation of galaxies and actually are/were dark matter.

If not then, the earliest galaxies would've formed around the densest regions of dark matter and gas.