The author suggests that tiny primordial black holes, hypothetical objects formed shortly after the Big Bang, may have played a key role by swallowing large amounts of antimatter. (Image for representation: Unsplash)One of the biggest questions in science is a simple yet profound one: why does anything exist at all? According to the current scientific understanding of the Big Bang theory, the Big Bang originally had close to an equal amount of matter and antimatter. Antimatter is essentially the opposite of matter and consists of antiprotons and antielectrons. When matter and antimatter combine, they annihilate each other.If the levels of matter and antimatter had stayed perfectly balanced, the universe would be empty today. There would be no galaxies, stars, planets, or life of any kind. However, it is quite clear that the universe is not empty and that matter is dominant.A new idea involving black holesNikodem Poplawski from the University of New Haven has given a new explanation in his paper published on arXiv. He suggests that tiny primordial black holes, hypothetical objects formed shortly after the Big Bang, may have played a key role by swallowing large amounts of antimatter.“Primordial black holes are hypothetical black holes that formed soon after the Big Bang because of extreme, high-density fluctuations in the early universe. They are good candidates for being the seeds of supermassive black holes at the centres of massive galaxies, as well as of intermediate-mass black holes at the centres of globular clusters,” Poplawski said during an interview with Space. “There are other models of elimination of antimatter, but they all assume some physics beyond the Standard Model of particle physics.Also Read | How did supermassive black holes become such monsters? New study shows it may have been ‘feeding frenzy’“The mass asymmetry between matter and antimatter was surprising, but it immediately suggested to me that it could be a simple and natural cause of the observed matter-antimatter imbalance in the universe.”Why antimatter may have disappearedPoplawski’s idea is based on a possible difference between matter and antimatter under extreme early-universe conditions. While experiments today show that matter and antimatter have nearly identical masses, his hypothesis suggests they may not have behaved identically at very high densities.“The mass asymmetry and the resulting black-hole capture asymmetry produced the matter–antimatter imbalance in the observable universe without violating the conservation of baryon number and invoking new physics beyond the Standard Model,” Poplawski explained.Story continues below this adBecause heavier or slower-moving particles are more easily captured by gravity, antimatter may have been more likely to fall into black holes.“Because the probability for gravitational capture of a massive particle by a black hole increases as its speed decreases, the antimatter particles were captured by black holes at larger rates than the corresponding matter particles,” Poplawski said. “The missing antimatter fell into primordial black holes, and what did not fall was annihilated by matter.”Clues from early black holesThis idea could also help explain another puzzle. Observations from the James Webb Space Telescope have revealed very massive black holes forming surprisingly early in the universe’s history. Some appear to have formed less than a billion years after the Big Bang, earlier than many models had predicted.Also Read | Galactic cosmic rays: Invisible rain that never stops fallingPoplawski believes that if early black holes consumed large amounts of antimatter, they could have grown faster than expected.Story continues below this ad“Primordial black holes consumed more antimatter than matter, and because antimatter was much heavier than matter, primordial black holes enormously increased their masses,” he said. “This could explain how supermassive black holes recently observed in the early universe have grown so quickly, he statedThe idea is still in its early stages and has not been confirmed. A key challenge is proving that primordial black holes actually existed, as they remain hypothetical. © IE Online Media Services Pvt LtdTags:black holes