Scientists looked at the merging of two black holes into one massive object, providing solutions into decades-old equations that work to describe how these collisions occur.
These insights could have an influence on how black holes are studied as well as how we search for mysterious gravitational waves, the University of Texas, Dallas reported. Albert Einstein's general theory of relativity suggests two massive objects orbiting within a binary system would move closer as the system emits radiation in the form of gravitational waves.
"An accelerating charge, like an electron, produces electromagnetic radiation, including visible light waves. Similarly, any time you have an accelerating mass, you can produce gravitational waves," said Michael Kesden, assistant professor of physics at UT Dallas. "The energy lost to gravitational waves causes the black holes to spiral closer and closer together until they merge, which is the most energetic event in the universe. That energy, rather than going out as visible light, which is easy to see, goes out as gravitational waves, which are very weak and much more difficult to detect."
The Laser Interferometer Gravitational-Wave Observatory (LIGO) experiment aims to be the first to directly observe these gravitational waves, which would unlock secrets of the universe.
"The equations that we solved will help predict the characteristics of the gravitational waves that LIGO would expect to see from binary black hole mergers," Kesden said. "We're looking forward to comparing our solutions to the data that LIGO collects."
The now-solved equation deals with the spin angular momentum of binary black holes, which is referred to as "precession." Angular momentum is measured by the amount of rotation seen in a spinning object, spin angular momentum also looks at rotation speed and direction in which it points. Orbital angular momentum applies to a system in which objects orbit around each other. In systems such as those containing binary black holes the directions of angular momenta have been found to precess over time.
"In these systems, you have three angular momenta, all changing direction with respect to the plane of the orbit - the two spin angular momenta and the one orbital angular momentum," Kesden said. "The solutions that we now have describe the orientations of the precessing black hole spins."
The new solutions could also allow researchers to statistically track spin precession from black hole formation to merger much quicker than before.
"We can do it millions of times faster than was previously possible," Kesden said. "With these solutions, we can create computer simulations that follow black hole evolution over billions of years. A simulation that previously would have taken years can now be done in seconds. But it's not just faster. There are things that we can learn from these simulations that we just couldn't learn any other way."
The findings were published in the Feb. 27 issue of the journal Physical Review Letters.
