It can be viewed as the \u201cglue\u201d that holds galaxies together, but we do not know what it is made of at a fundamental level. Most physicists think dark matter is composed of an as-yet-undiscovered sub-atomic particle. <\/p>\n
But ancient black holes from before the big bang<\/a> also fit the bill. They are dark, but also carry mass \u2013 exactly the properties required. <\/p>\n I have explored this idea in a new paper<\/a>. Of course, the idea of relic black holes also requires a re-think of the big bang itself.<\/p>\n For nearly a century, cosmologists traced the history of the universe back to this single, dramatic moment. But maybe this wasn\u2019t the absolute beginning of time. Perhaps there was a universe before the big bang. <\/p>\n Under this scenario, the universe collapsed before undergoing an expansion. The big bang represents the transition<\/a> between the two phases.<\/p>\n A conventional view of how the universe came to be. Here, the Big Bang is immediately followed by a period of rapid expansion known as inflation. The big bang model has been remarkably successful. It explains the cosmic microwave background \u2013 the afterglow of the early universe \u2013 and predicts the large scale distribution of galaxies with astonishing accuracy.<\/p>\n But in Einstein\u2019s theory of general relativity<\/a>, it is also a singularity \u2013 a point where density becomes infinite and the known laws of physics break down.<\/p>\n Many physicists interpret this not as a physical reality, but as a sign that something is missing. Singularities are less like physical objects and more like mathematical warnings: they tell us that our current theories cannot describe the earliest moments of the universe.<\/p>\n A bounce, not a bang<\/p>\n One alternative is a bouncing cosmology<\/a>. In this picture, the universe undergoes a phase of contraction before the big bang, reaching an extremely high \u2013 but finite \u2013 density. Instead of collapsing into a singularity, it rebounds, beginning a new expanding phase.<\/p>\n Bouncing models have been explored for decades, often requiring modifications to gravity or exotic new ingredients. But our work shows that a bounce can arise as a regular solution within standard physics, when gravity and the effects of quantum mechanics \u2013 the laws governing nature at the tiniest scales \u2013 are consistently taken into account.<\/p>\n In standard cosmology, the big bang is quickly followed by a period where the early universe undergoes a period of rapid and exponential expansion. This stage, known as inflation<\/a>, effectively erases all traces of earlier structures.<\/p>\n Illustration of a large black hole. Could relic black holes explain the mystery of dark matter? The situation is different for a bouncing universe. In our work, we found that things larger than 90 metres could have survived the transition from collapse to expansion. This leaves behind \u201crelics\u201d that carry information from a previous cosmic epoch. These relics can include black holes, gravitational waves and density fluctuations.<\/p>\n Quantum physics contains a powerful clue to how this is possible. According to the Pauli exclusion principle<\/a> \u2013 a cornerstone of quantum theory \u2013 matter becomes \u201cdegenerate\u201d at extremely high densities. The matter generates a pressure that resists further compression even in the absence of heat.<\/p>\n In our model, a similar effect operates on cosmological scales. It may explain why the universe doesn\u2019t collapse completely \u2013 and why structures formed before or during the bounce can survive into the expanding phase.<\/p>\n Surviving the apocalypse<\/p>\n We identify two main routes through which relic black holes can arise.<\/p>\n The first one is direct survival. Compact objects and perturbations (fluctuations in density or gravity) generated during the collapse phase of the universe can persist through the bounce. <\/p>\n The second route is even more intriguing. During contraction, matter naturally clumps under gravity, forming structures similar to the halos that host galaxies today. After the bounce, they are able to collapse efficiently into black holes.<\/p>\n Galaxies and stars from the contraction phase effectively collapse into black holes, erasing most of their detailed structure but preserving their mass. <\/p>\n Could these black holes be dark matter? For decades, the leading candidate has been a fundamental particle \u2014 but none has been detected despite extensive searches.<\/p>\n Could the \u2018little red dots\u2019 seen by JWST represent relic black holes? Relic black holes offer a compelling alternative. If the bounce produces enough of them, they could make up a significant \u2014 perhaps dominant \u2014 fraction of dark matter.<\/p>\n This idea may also connect to one of the most intriguing observational puzzles of recent years.<\/p>\n The James Webb Space Telescope (JWST)<\/a> has revealed a population of compact, extremely red objects in the early universe, sometimes called \u201clittle red dots\u201d<\/a>. These astronomical sources appear to be unexpectedly massive and luminous only a few hundred million years after the big bang.<\/p>\n Many astronomers suspect they are associated with rapidly growing black holes \u2013 perhaps the seeds of the supermassive black holes<\/a> found at the centres of galaxies today. But their existence is difficult to explain within standard cosmology. How could such massive objects form so quickly?<\/p>\n Relic black holes provide a natural explanation. If massive seeds already existed immediately after the bounce, the early universe would not need to start from scratch. Supermassive black holes could grow from ancient survivors rather than newly formed objects.<\/p>\n In this sense, JWST may already be glimpsing the descendants of pre-bounce relics.<\/p>\n A new cosmological framework<\/p>\n Taken together, the bounce scenario offers a unified way to address several long-standing problems in cosmology.<\/p>\n The big bang singularity is replaced by a quantum transition. This transition could be related to the concept of the \u201cEinstein\u2013Rosen bridge\u201d<\/a>: a mathematical link between two disparate regions of spacetime.![\"\"](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/04\/file-20260409-57-aljd8a.jpg\")
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\n Bicep2 Collaboration<\/a><\/p>\n![\"Black](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/04\/file-20260409-57-vwjxpg.jpg\")
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\n NASA\/Caltech-IPAC\/Robert Hurt<\/a><\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/04\/file-20260408-57-j0ei26.png\")
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\n Image: NASA, ESA, CSA, STScI, Dale Kocevski (Colby College)<\/a><\/p>\n
\nInflation emerges naturally from the dynamics near the bounce.<\/p>\n