The earliest black holes in the universe may still be with us, surprising study claims
A few moments after the Big Bangthe newborn universe was a wild and hot place. In this cosmic soup, primordial black holes – the first black holes in the universe, formed from extremely dense pockets of matter – could quickly take shape.
For centuries, our understanding of these objects, especially smaller ones, was that they eventually disappeared through a quantum process called Hawking radiation. It seemed like destiny was settled.
But a new survey, published in January in the arXiv preprint databaseopened a different path. This research claims that these objects did not always shrink – sometimes, they could grow, becoming cosmic devourers that absorbed radiation from the early universe.
This unexpected appetite not only changes the individual fate of the first black holes; it also transforms the way we see the past of the universe – and, above all, it changes our search for dark matter, the invisible scaffolding that holds galaxies together.
Hungry newborns
Primordial black holes are a fascinating idea in cosmology. Unlike the usual black holes born from the collapse of stars, these objects would have formed in the first moments after the Big Bang, from extreme densities in the initial soup of the universe. They could range from microscopic sizes to masses greater than that of the sun.
For a long time, general relativity told us that these objects, especially the smaller ones, would slowly lose mass due to Hawking radiation. They would evaporate and disappear into nothingness.
This is where the story takes a twist. The early universe was not just a quiet void around these primordial black holes; it was a thick, hot soup, full of radiation – with photons zipped everywhere.
This new research adds an essential piece to the puzzle: the direct absorption of this thermal radiation. If the collapse efficiency of a primordial black hole exceeds a certain point calculated in the new research, it does not slowly evaporate; he begins to feed. These black holes become silent, hungry cosmic devourers, the new study suggests.
This new understanding changes everything about how we think about the primitive cosmos and the fate of these ancient objects. Their ability to grow means they can live much longer than we previously thought, leading to extended lifespans and substantial mass.
If primordial black holes can grow by absorbing radiation, then a much wider range of initial masses could still exist today, acting as the unseen of the universe. dark matter. The research indicates that this expanded range depends heavily on what is called the absorption efficiency parameter – a measure of how quickly and efficiently the black hole can feed on the matter around it.
For example, if this parameter is 0.3, the allowable range for a primordial black hole to form and become dark matter extends from 10^16 grams to 10^21 grams. If the parameter is 0.39, then the range is from 5*10^14 grams to 5*10^19 grams. Previously, it was thought that primordial black holes could not be so massive and still be responsible for dark matter.
This work makes us think a lot about the first moments of the universe. This requires a fundamental reassessment of how these objects evolve and their potential to explain the mystery of dark matter. It’s not just a little edit a template; it is a new chapter in our cosmic history. We thought we knew the life cycles of these objects, but it turns out the universe had other plans.
Black Hole Quiz: How Supermassive Is Your Knowledge of the Universe?
