Cutting-edge simulations conducted by astrophysicists at Maynooth University indicate that in the turbulent and dense primordial cosmos, nascent black holes, termed ‘light seeds,’ possessed the capacity to swiftly accrete matter, potentially evolving to rival the immense black holes observed at the core of nascent galaxies.
Computer visualization showing baby black holes growing in a young galaxy in the early Universe. Image credit: Maynooth University.
“Our findings suggest that the volatile conditions prevalent in the early Universe propelled nascent, smaller black holes into a voracious accretion phase, enabling them to burgeon into the supermassive structures observed subsequently by consuming surrounding material,” stated Daxal Mehta, a doctoral candidate at Maynooth University.
“Leveraging sophisticated computational models, we have demonstrated that the inaugural generation of black holes—those originating mere hundreds of millions of years post-Big Bang—experienced prodigious growth, expanding to masses tens of thousands of times that of our Sun.”
“This pivotal research addresses a significant conundrum in cosmology,” observed Dr. Lewis Prole, a postdoctoral researcher at Maynooth University.
“Specifically, it elucidates how black holes formed in the early cosmos, as detected by the James Webb Space Telescope of NASA/ESA/CSA, could attain such colossal masses with remarkable celerity.”
The intensely concentrated, gas-rich environs within early galaxies facilitated transient episodes of ‘super-Eddington accretion’; a phenomenon describing black hole growth rates that exceed conventional or stable limits.
This accelerated consumption occurs at such an extreme pace that it would theoretically expel ejected matter via radiation, yet the black holes continue to absorb material regardless.
The outcomes of this investigation provide a crucial conceptual bridge connecting the genesis of the first stars with the subsequent emergence of supermassive black holes.
“Previously, it was postulated that these diminutive black holes were intrinsically incapable of accumulating sufficient mass to evolve into the gargantuan black holes observed at the nuclei of early galaxies,” Mehta remarked.
“Our current work substantiates that these primordial black holes, despite their initial modest size, possess the inherent potential for exceptionally rapid growth under conducive environmental circumstances.”
Black holes are categorized into ‘heavy seed’ and ‘light seed’ classifications.
The ‘light seed’ variants initiate existence as relatively compact entities, typically possessing masses no greater than ten to a few hundred times that of our Sun, and must undergo substantial accretion to attain ‘supermassive’ status—millions of times the solar mass.
Conversely, ‘heavy seed’ black holes commence their existence with significantly greater intrinsic mass, potentially reaching up to one hundred thousand times the solar mass at their inception.
Until this recent research, the prevailing astronomical consensus held that ‘heavy seed’ black holes were a prerequisite for explaining the presence of supermassive black holes found at the centers of most large galactic structures.
“This perspective is now subject to considerable doubt,” commented Dr. John Regan, an astrophysicist at Maynooth University.
“The formation of ‘heavy seeds’ is considered somewhat atypical, likely requiring specialized and infrequent conditions.”
“Our simulations demonstrate that black holes of conventional stellar mass, essentially ‘garden variety’ entities, are capable of accreting at extraordinary rates within the early Universe.”
This research not only reframes our understanding of black hole origins but also underscores the indispensable role of high-fidelity simulations in unraveling the most ancient enigmas of the cosmos.
“The early Universe exhibits a far more dynamic and chaotic character than initially surmised, harboring a considerably more abundant population of massive black holes than anticipated,” Dr. Regan asserted.
The findings also hold significant implications for the Laser Interferometer Space Antenna (LISA) mission, a collaborative project by ESA and NASA slated for deployment in 2035.
“Future gravitational wave detections from the LISA mission may offer the capability to observe the mergers of these primordial, rapidly evolving nascent black holes,” Dr. Regan noted.
A scientific publication detailing these discoveries was released this week in the esteemed journal Nature Astronomy.
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D.H. Mehta et al. The growth of light seed black holes in the early Universe. Nat Astron, published online January 21, 2026; doi: 10.1038/s41550-025-02767-5
