21 Feb. () –
Researchers have developed a new method to analyze the waves emitted by black holes when they collide, as they publish in the journal ‘Physical Review Letters’.
In 2015, scientists first detected gravitational waves, ripples in space-time that occur when large cosmic events — such as the collision and merger of two black holes — disrupt the cosmos. The observation of these waves confirmed Einstein’s theory of general relativity, which predicted that they would occur. if space-time worked the way he thought it would.
In the seven years since then, almost 100 merging black holes have been detected by observing the gravitational waves emitted by these extraterrestrial phenomena.
Now, thanks to new research from a 14-person team led by Caltech doctoral student and Columbia College alumnus Keefe Mitman; postdoctoral student from Columbia University (United States) Macarena Lagos; Columbia professor Lam Hui, and University of Mississippi professor Leo Stein, the ability to model these cosmic events has become more sophisticated. The improved model they have developed paves the way for a deeper understanding of the structure of merging black holes.
The team has developed a more complex way of modeling the signal emitted by gravitational waves by including nonlinear interactions in the models. This modeling method will allow scientists to better understand the structure of what happens inside black holes, and will also help to test whether Einstein’s theory of general relativity correctly describes the behavior of gravity in extreme astrophysical environments.
“This is a big step in preparing us for the next phase of gravitational wave detection, that will deepen our understanding of gravity and these incredible phenomena that take place in the far reaches of the cosmos“, says Lagos, co-author of the study.
The research comes just as next March LIGO, the observatory that first detected gravitational waves, will turn on to collect new observations of phenomena taking place in the far reaches of space.
The observatory has not been working since 2020, when it was closed due to the pandemic. Other major detectors are expected to start collecting data in the next few years, making it even more important that have sophisticated models to interpret the incoming information.
Lam Hui, co-author of the study, uses an analogy to describe the information that gravitational waves can provide: “If I give you a box and ask you what’s inside, the natural thing is that you shake it. That would tell you if there are any inside the box.” candy or coins That is what we are trying to do with these models, is to get an idea of the internal contents of a black hole by listening to the sound that is emitted when it is shaken.“, Explain.
“The ‘shock’ in the case of black holes is the disturbance that occurs when two collide and merge. Listening to the harmonics it emits, we can assess the space-time structure of the black hole”Add.
Until now, models of gravitational waves emitted after the merger of two black holes only included linear interactions, which work well and provide valuable information about the structure and content of black holes. This new model, however, could improve the overall accuracy of black hole models by up to 10%, according to the paper’s authors.
To understand the importance of using nonlinearity to describe gravitational waves, the authors described waves in an ocean: A wave that rises and falls without spewing water into the air could be described with a linear equation, but a wave that waxes and wanes presents nonlinear interactions.
Thus, while one part of the water swells at the bottom of the wave, another part rushes simultaneously to the left, right, up and down in tendrils and drops of water above it. A non-linear model of the wave would allow us to understand how and when all the water in the wave moves, including those airborne droplets. Gravitational waves are similar to water waves, and the new model is capable of accounting for the extraterrestrial equivalent of extra water droplets.
“We are preparing for when we will be detectives of gravitational waves, when we will dig deep to understand as much as we can about their nature,” Stein announces.
