A team has computed the entanglement entropy of a discretized scalar field in the fixed spacetime background of an evolving wormhole, a class of spherically symmetric, time-dependent geometries. In both expanding and contracting models, the researchers find dynamically generated entanglement: the evolution of spacetime itself creates quantum correlations between regions separated by the wormhole throat.

The work fits into a research line aimed at understanding how spacetime geometry and quantum entanglement constrain each other, a central theme in AdS/CFT and in attempts to derive the Bekenstein-Hawking area law from quantum mechanics. Specifically, it addresses whether the area law still describes entanglement entropy when the background is not static but evolves in time.

The method combines scalar field discretization with numerical computation of the entanglement entropy at each step of the evolution. Far from the throat, the entropy is well described by the leading term of the area law, although its coefficient depends sensitively on the value of the UV cutoff imposed by the discretization. As the UV cutoff is decreased, this dependence progressively weakens, providing numerical evidence that the coefficient approaches a cutoff-independent value in the continuum limit.

The most striking result appears near the throat: there, the entanglement entropy shows a double-dip structure that cannot be accounted for by either the leading or the logarithmic contribution to the area law. This feature suggests that the throat region encodes additional geometric information beyond what the usual corrections capture. The finding opens the door to investigating which quantum degrees of freedom shape that structure and whether it persists in simulations with more realistic fields or in full three-dimensional geometries.