Are stupendously large black holes part of dark matter?
What's the story
A recent study has debunked the theory that stupendously large black holes could be a major component of dark matter. Dark matter is an unseen substance that scientists think holds galaxies together with its gravitational pull. The new research shows that these incredibly massive black holes, which are more than 100 billion times heavier than our Sun, don't account for a significant portion of this mysterious cosmic material.
Mystery
What is dark matter and why is it important?
Dark matter is believed to make up about five-sixths of all matter in the universe.
It was first proposed decades ago to explain why galaxies don't fly apart at their observed rotation speeds.
The idea is that this unseen substance's gravitational pull helps keep galaxies intact.
However, the exact nature of dark matter remains a mystery.
Black hole candidates
Hypothetical black holes
The study's authors looked into the possibility of "stupendously large black holes" as a potential source of dark matter.
These hypothetical objects would be heavier than entire galaxies and are extremely difficult to detect in the vastness of space.
However, no such black holes have been found so far, with the largest known black hole weighing about 36 billion times that of our Sun.
Data scrutiny
Research methodology
The researchers examined the light from the universe's early days, known as the cosmic microwave background.
This ancient light provides a snapshot of how matter was distributed in the infant universe.
The study found that this cosmic microwave background isn't "grainy" like it would be if stupendously large black holes were a major part of dark matter.
Next steps
Findings don't rule out existence of stupendously large black holes
The researchers clarified that their findings don't rule out the existence of stupendously large black holes, but rather suggest they don't make up a large part of dark matter.
They also hinted at the possibility of exploring smaller black holes, akin to asteroids, as potential candidates for dark matter.
Their study will be published in the journal Physical Review Letters on October 26.