Groundbreaking investigations spearheaded by Professor Enrique Gaztañaga, affiliated with the University of Portsmouth and the Institute of Space Sciences in Barcelona, posit that a segment of black holes predates the Big Bang and successfully navigated a cosmic “bounce,” potentially illuminating the enigma of dark matter, the presence of gravitational-wave backgrounds, and the accelerated formation of supermassive black holes and galaxies in the nascent Universe.
Gaztañaga proposes a new dark matter mechanism in which relic black holes originate from a pre-Big-Bounce collapse phase.
“For nearly a century, our understanding of cosmic history has been anchored to a singular, momentous event referred to as the Big Bang,” stated Professor Gaztañaga.
“Within the prevailing cosmological framework, the emergence of space and time is attributed to an exceedingly hot, dense primordial state approximately 13.8 billion years in the past, succeeded by eons of cosmic expansion and the genesis of galaxies.”
“This established paradigm has demonstrated exceptional efficacy, providing a cogent explanation for the Cosmic Microwave Background (CMB)—the residual thermal radiation from the early cosmos—and precisely forecasting the distribution of galaxies across immense cosmic expanses.”
“Nevertheless, several profound conundrums within the field of physics persist without resolution. The catalyst for the Big Bang remains unknown, the reason for the Universe’s initiation in such a specific state is unclear, the mechanism behind the brief but intense period of accelerated expansion known as inflation is elusive, and the identity of dark matter, which dwarfs ordinary matter by a factor of approximately five, is still a mystery.”
“Our current research delves into a speculative avenue that could potentially interconnect these disparate enigmas: it is conceivable that the Universe did not commence with a singular ‘bang’ but rather transitioned from a cosmic bounce, mirroring the inflationary epoch, with some of the Universe’s most ancient structures potentially persisting as vestiges from a pre-bounce era.”
Certain black holes might have coalesced during the antecedent cosmic epoch and endured the rebound, leaving behind residual entities that could still exert influence on galactic configurations billions of years later.
Alternatively, others could have formed shortly after the bounce from amplified density perturbations, where primordial matter was distributed unevenly, forming more robust and discernible aggregations than typically observed.
These intensified concentrations of matter would succumb more readily to gravitational collapse, thereby increasing the probability of early formation for substantial cosmic architectures—including black holes.
According to Einstein’s theory of general relativity, the Big Bang signifies a singularity—a theoretical point where density becomes infinite, rendering our current physical laws inapplicable.
This breakdown of established physics often leads many scientists to conclude that our current descriptive models of the Universe’s earliest moments are incomplete.
An alternative hypothesis proposes a “bouncing cosmology,” wherein our Universe originates from a vast cloud undergoing initial contraction, followed by a subsequent rebound into expansion.
Rather than collapsing into an infinitely dense singularity, the Universe reaches an extremely high but finite density before reversing its trajectory.
“Singularities frequently serve as indicators that our theoretical frameworks have reached their operative boundaries,” Professor Gaztañaga remarked.
“A cosmic bounce offers a mechanism for the Universe to transition from a state of contraction to one of expansion without necessitating the invocation of novel, hypothetical physics.”
Researchers theorize that the bounce could naturally arise from quantum mechanical principles. At exceptionally high densities, quantum effects generate immense pressure, which impedes further compression of matter indefinitely—a phenomenon already observed to stabilize dense celestial bodies like white dwarfs and neutron stars and which also accounts for the inflationary expansion phase.
In the context of the new theoretical model, a comparable effect could manifest on cosmological scales. As the Universe contracts, this quantum pressure might arrest the collapse, initiating a reversal and subsequent expansion.
This hypothesized bounce mechanism could also provide explanations for two of the most significant unresolved questions in cosmology.
Firstly, it might elucidate the reason for the Universe’s rapid and uniform expansion in all directions during its early stages.
Secondly, it could offer insight into the current accelerated expansion of the Universe, an effect presently attributed to dark energy, a poorly understood force.
A compelling implication of this theory is that certain structures formed during the contraction phase may have successfully traversed the bounce event.
The updated computational analyses suggest that compact celestial bodies exceeding approximately 90 meters in dimension could have successfully navigated this transitional phase and re-emerged in the expanding Universe as ancient relics from a prior era.
Potential candidates for these relic entities include gravitational waves, density fluctuations, and primordial black holes.
These ancient black holes could provide a solution to the mystery of dark matter, the invisible substance that dictates the structure of galaxies and the large-scale cosmic web.
If a substantial population of these black holes formed during the bounce, they might constitute a significant proportion—perhaps even the entirety—of dark matter.
This hypothesis may also shed light on recent findings from the James Webb Space Telescope (operated by NASA, ESA, and CSA), which has detected unexpectedly massive celestial objects in the early Universe, colloquially referred to as “little red dots.”
A considerable number of astronomers suspect these observed phenomena are associated with rapidly accreting black holes that appeared remarkably early in cosmic history, shortly after the Big Bang.
“If massive black holes were already in existence immediately following the bounce, the early Universe would not have had to construct the initial galaxies from an empty slate,” commented Professor Gaztañaga.
The theoretical framework also posits testable predictions that could be verified through forthcoming observational endeavors.
Scientists may investigate the possibility of detecting relic gravitational waves originating from a preceding cosmic epoch or discern subtle patterns within the CMB that retain imprints of the Universe prior to the Big Bang.
“Substantial investigation is still required to validate these concepts,” Professor Gaztañaga acknowledged.
“However, if the Universe indeed underwent a cosmic bounce, the enigmatic structures that currently shape galaxies might indeed be remnants from a cosmic epoch that predated the conventionally understood Big Bang.”
His publication detailing these findings has been featured in the esteemed journal Physical Review D.
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Enrique Gaztañaga. 2026. Cosmological bounce relics: Black holes, gravitational waves, and dark matter. Phys. Rev. D 113, 043544; doi: 10.1103/pr4p-6m49
