A new mathematical model suggests that quantum entanglement between black holes can create bumpy space-time tunnels resembling caterpillars. Researchers at Brandeis University have found that these wormholes are typically lumpy rather than smooth, differing from earlier theories. This work aims to shed light on the mysterious interiors of black holes.
In 2013, physicists Juan Maldacena at Princeton University in New Jersey and Leonard Susskind at Stanford University in California proposed that for black holes, an Einstein-Rosen bridge—a wormhole connecting distant points in space-time—could be equivalent to an Einstein-Podolsky-Rosen pair, where particles are linked by quantum entanglement.
Building on this, Brian Swingle at Brandeis University in Massachusetts and his colleagues have analyzed entangled black holes mathematically. Their findings, published in Physical Review Letters (DOI: 10.1103/btw6-44ry), reveal a more complex picture. "Studying wormholes that connect quantumly entangled black holes ultimately helps researchers understand more about black holes’ interiors, which are poorly understood places full of mystery because of how remarkably strongly gravity is acting there," Swingle says.
The team explored whether wormholes follow a rule similar to black holes, where interior size corresponds to quantum complexity. Lacking a full theory of quantum gravity, they used an incomplete model linking quantum physics and gravity, which Swingle believes offers valuable insights.
Their calculations show a correspondence between a wormhole's microscopic quantum randomness and its geometric length. Typical wormholes are less likely to be smooth and more prone to bumps made of matter, earning the "Einstein-Rosen caterpillar" nickname. This contrasts with the 2013 model, which may apply only to special cases yielding smooth wormholes.
Donald Marolf at the University of California, Santa Barbara, notes that the work adds insight but does not cover the most common entanglement cases. The vast array of possible black hole states exceeds those in our universe, requiring further study. Swingle suggests future use of quantum computers to simulate these phenomena, potentially advancing both quantum theory and gravity research.