Study ties spacetime geometry to quantum information in new derivation

A new study argues that gravity and quantum information are closely connected, with spacetime geometry emerging from how information is stored in quantum fields. The authors rebuild Ted Jacobson's thermodynamic route to Einstein's equations using mathematical techniques that tie quantum information to spacetime geometry. Published in Physical Review Letters, the work may offer clues about why gravity exists, though the authors present this as tentative.

A 1995 paper by Ted Jacobson showed that thermodynamics could yield Einstein's field equations. That earlier result suggested gravity might be emergent rather than fundamental. The new study, published in Physical Review Letters, instead uses quantum relative entropy, a quantum-information measure of how distinguishable two states are.

At a spacetime horizon, the authors relate this quantity to energy flux through the horizon. Combining that with the Bekenstein-Hawking connection between horizon area and entropy yields equations for how quantum fields influence spacetime curvature. Coauthor Albert Much notes the proof's novelty, while acknowledging that the core information-gravity ingredients were already known.