Einstein’s Equations Suggest Gravity Can Break and Reconnect, Physicists Say
Physicists Luca Comisso of Columbia University and Felipe A. Asenjo of Universidad Adolfo Ibáñez in Chile calculate that gravitational fields may break and reconnect like solar magnetic fields, a process they call gravitational reconnection that could move energy into matter.
Einstein's equations reveal gravity may be able to break and reconnect, much like the magnetic fields that drive solar flares, according to new calculations by physicists Luca Comisso of Columbia University and Felipe A. Asenjo of Universidad Adolfo Ibáñez in Chile.
They call the process gravitational reconnection. Under the right conditions, they say, it would let energy flow from the gravitational field into matter.
The work comes more than 100 years after Albert Einstein developed his theory of gravity.
What the researchers found
Comisso is an associate research scientist in Columbia's Departments of Astronomy and Physics and the Columbia Astrophysics Laboratory. He and Asenjo reexamined Einstein's equations using a mathematical formulation that reveals similarities between gravity and electromagnetism.
They then asked what happens when the conditions that keep gravitational field connections intact break down. Under certain circumstances, they found, the fields can reconnect in new configurations.
Comisso stressed that this is not new physics. "We are not modifying general relativity or introducing new physics beyond it," he said. "Rather, we are identifying physical principles that have remained unrecognized for more than a century."
The solar flare comparison
On the Sun, magnetic field lines thread through electrically charged gas called plasma. They can be pulled, twisted and stretched. Sometimes they snap and reattach in a different pattern, a process called magnetic reconnection that powers solar flares.
"When they break and reconnect, they release energy," Comisso said.
Gravity works in four-dimensional spacetime, made of three dimensions of space and one of time. So the researchers describe it with field "sheets" rather than lines. "Adding one dimension to a line gives you a plane," Comisso explained.
The sheets are a mathematical picture, not physical surfaces that literally tear. Their reconnection describes a way for the gravitational field to hand energy to matter.
How the idea developed
The pair built on an earlier paper written with a third physicist, Maricarmen A. Winkler of Adolfo Ibáñez University. Those calculations showed that gravitational fields can behave as though their connections are frozen in place, preserving links between regions as spacetime evolves.
That mirrors magnetic fields in plasma, where field lines stay connected even as the plasma flows. Since magnetic connections can eventually break, the team tested whether gravity's could too.
Comisso said the team had suspected some overlap, since Einstein's equations can be rewritten in forms resembling those of electromagnetism. "However, we did not know how far this analogy would extend," he said.
The answer came only after working through the calculations "step by step at the blackboard," he said, when they realized how closely gravitational fields could follow the principles that govern magnetic fields in plasmas.
Why it could matter
Researchers believe the connection could give new insight into gravity under extreme conditions, including collisions between black holes. In regions where gravity severely distorts spacetime, even the most powerful computer simulations are hard to interpret.
The approach could help scientists identify fundamental rules governing gravitational fields in those regions.
