Holes in the fabric of space and time may be responsible for dark matter

Your typical, run-of-the-mill black holes have long ago been eliminated from the running as candidates for dark matter, that mysterious substance that appears to make up a large proportion of the mass in our universe, including our own galaxy.

The reason is simple: ordinary black holes come from the collapse of stars, which means that they were originally formed from what is called baryonic matter, ordinary matter. You are made of baryons and so are black holes.

We know from studying how the universe formed that the amount of matter that can come from baryons has an upper bound. That is from a process called nucleosynthesis which is what creates all the elements we see in the universe.

Most of the light elements such as Helium, Lithium, and Hydrogen we see in the universe today were formed after the Big Bang following what is called the “radiation dominated” period. Based on the density of such elements that we see in the universe today, there can be only so much baryon density total that came out of the cosmic furnace.

Unfortunately, dark matter we observe based on measurements of galaxies’ rotation rates, for example, is far above that value (about 5% upper bound on baryons vs. 30% dark matter that we see from gravity). In order for all our measurements to make sense, dark matter cannot be made of ordinary stuff, even if that is hidden inside a black hole. Indeed, there is no serious baryonic candidate for dark…