Black holes can exist in perfectly balanced pairs, kept in balance by a cosmic force, like a single black hole, according to research from the universities of Southampton, Cambridge and Barcelona.
Black holes can exist in perfectly balanced pairs, kept in balance by a cosmic force, like a single black hole, according to research from the universities of Southampton, Cambridge and Barcelona.
Black holes are regions of space around an infinitely dense “singularity” created by the collapse of a massive star. With many times the mass of the Sun, squeezed into only about 10 miles, black holes have such a strong gravitational pull that not even light can escape the boundary around them, called the event horizon. . Just as massive stars often exist in pairs orbiting each other, black holes can exist as binary systems. When these black holes move, they create gravitational waves – waves that have the structure of space-time, these waves carry away the angular momentum of the system. This brings the black holes closer together and eventually gravity takes over, causing them to merge into a larger black hole. Previously, scientists believed that this process was inevitable; all binary black holes were merging.
However, since the beginning of the 20th century, following Edwin Hubble’s discovery that galaxies are rapidly moving away from each other, scientists have understood that the Universe is expanding. Additionally, in the late 20th century, astronomers discovered that this expansion is actually accelerated and driven by dark energy.
Dark energy makes up 68% of the energy and matter in the Universe, although scientists still don’t know exactly what it is. Professor Oscar Diaz of the University of Washington said: “The standard model of cosmology shows that the universe began with the Big Bang and about 9.8 billion years ago was dominated by a mysterious force called energy Dark, this force accelerates the universe at a constant rate. . Southampton, lead author of the new study. Exposure to dark energy means that black holes are located in an expanding space-time field. Scientists wonder whether this expansion of space-time could help black holes keep a safe distance from each other. They solved this problem using mathematical models and found that two black holes can actually exist in equilibrium when the gravitational attraction between them is offset by expansion.
“From the observer’s point of view, a pair of black holes whose mutual attraction is compensated by expansion would look like a single black hole. It will be difficult to determine whether it is one black hole or two black holes,” Diaz added. At the same time, the gravitational force between the binary black holes will not allow the expansion of the Universe to push them apart. The researchers believe their solution is applicable to rotating black holes, known as Kerr black holes, and even more exotic black hole systems with large numbers of objects. “Our theory has been tested on several static black holes, but we think it also applies to rotating black holes. Furthermore, it seems realistic that our solution would hold for three or even four black holes, opening up a lot of possibilities,” added study co-author Jorge Santos of the University of Cambridge in the UK.
source: https://www.southampton.ac.uk/