New Gravitational-Wave Signal May Reveal Primordial Black Holes Born After the Big Bang
A 2025 LIGO–Virgo–KAGRA signal may reveal ultra-light primordial black holes—possible relics of the Big Bang and candidates for dark matter. Scientists stress the detection is tentative but potentially groundbreaking.
The Big Bang may have been the first to give scientists a clue of the existence of primordial black holes. The hint was a strange gravitational-wave signal which was recorded in November 2025 by the LIGO–Virgo–KAGRA observatories. This signal can be caused by the collision of two small black holes (which may not be bigger than a coin). In case it is real, astronomers explain that it would be a discovery of the first in terms of exotic remnants of the early universe.
Unusual gravitational-wave signal
According to reports, LIGO–Virgo–KAGRA detectors flagged an unusual gravitational-wave signal in November 2025 (event S251112cm). The data showed one merging object had a mass far below any known stellar remnant. Durham University physicist Djuna Croon said the finding would be “enormous” if confirmed, since standard astrophysics cannot explain it. The LIGO team cautions this could still be a rare noise glitch (false-alarm odds roughly 1 in 4 years). But even a small chance of a true signal is thrilling, because primordial black holes have long been theorised but never confirmed.
Primordial black holes: cosmic relics
