Tiny black holes explain galaxy flows and the expansion of the Universe express
Dark matter may not be particles but black holes from the Big Bang era. In the early Universe, which was like a swirling batter, they were like heavy lumps — barely moving, they gathered surrounding matter and spun it into the swift galaxy flows astronomers observe today. But there's a twist: the lightest holes, according to Hawking's theory, evaporate, emitting energy. This evaporation gently warms the cosmic 'batter' in its early stages, thereby changing the calculated rate of the Universe's expansion and smoothing out the notorious tension between different measurement methods.
One such hole weighs as much as an asteroid but is compressed to a point smaller than an atomic nucleus. Its evaporation is so unhurried that over the entire history of the Universe, it would lose only a minuscule fraction of its mass.