Dark Matter Can Create Massive Black Holes

Latest research revealed that dark matter could gather over vast periods of time at the heart of Jupiter-sized planets, creating black holes that eat these worlds from within. This striking concept may mean extrasolar planets, or "exoplanets," could be used to study the mystery of dark matter.

In this new model, superheavy dark matter particles could be trapped by exoplanets, losing energy and drifting toward that world's core. Once there, these superheavy dark matter particles accumulate until they collapse, forming a black hole. This black hole then ravenously eats its way out of its host planet.

This new dark matter/black hole theory doesn't work with all recipes of black holes, however. For instance, if dark matter particles meet and annihilate each other as some models suggest (as happens when electrons meet their antiparticles, positrons), then it wouldn't be possible for them to gather in quantities needed to collapse and birth a black hole.

Dark matter is troubling to scientists because, despite the fact that it accounts for 85 percent of the "stuff" in the universe, we have no idea what it is. The fact that dark matter doesn't interact with light means it can't be made up the electrons, protons, and neutrons that form the atoms that compose everything we see around us: the universe's ordinary matter — stars, planets, moons, living things, etc. This lack of interaction with electromagnetic radiation also makes dark matter effectively invisible. This puzzle has led to scientists to suggest all types of different particles that might possibly account for dark matter, many of which have different properties.

But there's another caveat to the dark matter recipe needed for this process to occur. The constituent particles would have to have very large masses. This rules out one of the most highly favored dark matter candidate particles, the axion, a hypothetical particle with a very small mass.

"If the dark matter particles are heavy enough and don't annihilate, they may eventually collapse into a tiny black hole," University of California, Riverside researcher Mehrdad Phoroutan Mehr said in a statement. "If the dark matter particles are heavy enough and don’t annihilate, they may eventually collapse into a tiny black hole."

Currently, the lightest black holes we are aware of are so-called stellar mass black holes. These are thought to have masses between around 3 and 100 times the mass of the sun. The logic behind this is sound, as these black holes are born when massive stars run out of nuclear fuel at the end of their lives. As a supernova explosion ejects the outer layers of these stars, their stellar cores collapse.

That means the mass range of stellar mass black holes is set by the masses of the progenitor stars that created them. Furthermore, the lower mass is set by the fact that stars with less than 1.4 times the mass of the sun (a value known as the Chandrasekhar limit) can't go supernova, so can't birth a black hole or a neutron star. Instead, these stars leave behind a white dwarf.

There's another mass limit to consider, too. The Tolman–Oppenheimer–Volkoff (TOV) limit divides stellar cores that create black holes and those that birth neutron stars. Though less well defined than the Chandrasekhar limit, the TOV limit suggests that after ejecting most of its matter, a stellar core needs to have at least 2.2 to 2.9 times the mass of the sun to form a black hole.

This limit is uncertain, as currently the lightest black hole we have detected and confirmed is around 3.8 times the mass of the sun, while the heaviest neutron star ever detected weighs in at 2.4 solar masses.

These planet-eating black holes would be much more diminutive than even the lightest stellar mass black hole if they adopt the mass of the planet they devour. The team proposes that this process could occur within planets with masses the same as Jupiter, which has around 0.001 times the mass of the sun.