New submitter GFS666 shares a report from Live Science: We may soon be able to test one of Stephen Hawking’s most controversial theories, new research suggests. In the 1970s, Hawking proposed that dark matter, the invisible substance that makes up most matter in the cosmos, may be made of black holes formed in the earliest moments of the Big Bang. Now, three astronomers have developed a theory that explains not only the existence of dark matter, but also the appearance of the largest black holes in the universe. “What I find personally super exciting about this idea is how it elegantly unifies the two really challenging problems that I work on — that of probing the nature of dark matter and the formation and growth of black holes — and resolves them in one fell swoop,” study co-author Priyamvada Natarajan, an astrophysicist at Yale University, said in a statement. What’s more, several new instruments — including the James Webb Space Telescope that just launched — could produce data needed to finally assess Hawking’s famous notion.
In the latest research, Natarajan, Nico Cappelluti at the University of Miami and Gunther Hasinger at the European Space Agency took a deep dive into the theory of primordial black holes, exploring how they might explain the dark matter and possibly resolve other cosmological challenges. To pass current observational tests, primordial black holes have to be within a certain mass range. In the new work, the researchers assumed that the primordial black holes had a mass of around 1.4 times the mass of the sun. They constructed a model of the universe that replaced all the dark matter with these fairly light black holes, and then they looked for observational clues that could validate (or rule out) the model.
The team found that primordial black holes could play a major role in the universe by seeding the first stars, the first galaxies and the first supermassive black holes (SMBHs). Observations indicate that stars, galaxies and SMBHs appear very quickly in cosmological history, perhaps too quickly to be accounted for by the processes of formation and growth that we observe in the present-day universe. “Primordial black holes, if they do exist, could well be the seeds from which all supermassive black holes form, including the one at the center of the Milky Way,” Natarajan said. And the theory is simple and doesn’t require a zoo of new particles to explain dark matter. “Our study shows that without introducing new particles or new physics, we can solve mysteries of modern cosmology from the nature of dark matter itself to the origin of supermassive black holes,” Cappelluti said in the statement. The model could be tested relatively soon, the report says. “The James Webb Space Telescope, which launched Christmas Day after years of delays, is specifically designed to answer questions about the origins of stars and galaxies. And the next generation of gravitational wave detectors, especially the Laser Interferometer Space Antenna (LISA), is poised to reveal much more about black holes, including primordial ones if they exist.”