can see the universe Prefer round things. Planets and stars tend to be spherical because gravity pulls clouds of gas and dust toward their centers of mass. The same is true for black holes (more precisely, black hole event horizons). According to theory, black holes should be spherically formed in the universe with three dimensions of space and one dimension of time.
But if our universe has higher dimensions, as is sometimes assumed, do the same restrictions apply? Are other black hole shapes possible in those settings?
The answer to the latter question is, as math tells us, yes. Over the past two decades, researchers have found occasional exceptions to the rule that restricts black holes to spherical shapes.
now new paper goes even further with a radical mathematical proof that an infinite number of shapes are possible in 5 or more dimensions. The paper shows that Albert Einstein’s general relativity equations can generate a wide variety of exotic high-dimensional black holes.
The new work is purely theoretical. I don’t know if such black holes exist in nature. But if we somehow detect such oddly shaped black holes, perhaps as microscopic products of collisions in particle colliders, we might automatically discover that our universe is of higher dimensions. I will show it to you,” he said. Marcus Coolia geometer at Stony Brook University and co-author of the new study Jordan Raynone, a recent Stony Brook Mathematics Ph.D. “So the question now is to see if we can detect anything in our experiments.”
black hole donut
Like so many stories about black holes, this one starts with Stephen Hawking. Specifically, it starts with his 1972 proof that the surface of a black hole at a given point in time must be a two-dimensional sphere. (A black hole is a three-dimensional object, but on its surface he has only two spatial dimensions.)
Until the 1980s and 1990s, extending Hawking’s theorem was largely unthinkable, but enthusiasm for string theory (an idea that presumably requires the existence of 10 or 11 dimensions) grew. Physicists and mathematicians then began to seriously consider what these extra dimensions meant for Black and his hole topology.
Black holes are some of the most complex predictions of Einstein’s equations (10 linked nonlinear differential equations) and are very difficult to deal with. In general, they can be explicitly resolved only in highly symmetric and simplified situations.
In 2002, 30 years after Hawking’s results, physicists Robert Emparan and Harvey Real—now at the Universities of Barcelona and Cambridge, respectively—found highly symmetric black hole solutions to the Einstein equations in five dimensions (four in space and one in time). Emparan and Real refer to this object as “black ring” – A three-dimensional surface with the general outline of a donut.
It’s hard to draw a 3D surface in 5D space, so let’s imagine a normal circle. All points of that circle can be replaced by a 2D sphere. The result of this circle-sphere combination is a three-dimensional object that can be thought of as a hard, lumpy donut.
In principle, such a donut-shaped black hole could form if it were spinning at the right speed. “If it spins too fast, it will fall apart, and if it spins too slowly, it will bounce back into a ball,” Raynone says. “Emparan and Reall found the sweet spot. Their ring was spinning fast enough to stay on as a donut.”
