Scattering strings off quantum extremal surfaces

Abstract

We consider a Hayden \& Preskill like setup for both maximally chaotic and sub-maximally chaotic quantum field theories. We act on the vacuum with an operator in a Rindler like wedge $R$ and transfer a small subregion $I$ of $R$ to the other wedge. The chaotic scrambling dynamics of the QFT Rindler time evolution reveals the information in the other wedge. The holographic dual of this process involves a particle excitation falling into the bulk and crossing into the entanglement wedge of the complement to $r=R\backslash I$. With the goal of studying the locality of the emergent holographic theory we compute various quantum information measures on the boundary that tell us when the particle has entered this entanglement wedge. In a maximally chaotic theory, these measures indicate a sharp transition where the particle enters the wedge exactly when the insertion is null separated from the quantum extremal surface for $r$. For sub-maximally chaotic theories, we find a smoothed crossover at a delayed time given in terms of the smaller Lyapunov exponent and dependent on the time-smearing scale of the probe excitation. The information quantities that we consider include the full vacuum modular energy $R\backslash I$ as well as the fidelity between the state with the particle and the state without. Along the way, we find a new explicit formula for the modular Hamiltonian of two intervals in an arbitrary 1+1 dimensional CFT to leading order in the small cross ratio limit. We also give an explicit calculation of the Regge limit of the modular flowed chaos correlator and find examples which do not saturate the modular chaos bound. Finally, we discuss the extent to which our results reveal properties of the target of the probe excitation as a "stringy quantum extremal surface" or simply quantify the probe itself thus giving a new approach to studying the notion of longitudinal string spreading.

63 pages, 7 figures, Added references

References in corpus (7)

• Black holes as mirrors: quantum information in random subsystems
• The Pomeron and Gauge/String Duality
• Bulk Emergence and the RG Flow of Entanglement Entropy
• A World without Pythons would be so Simple
• Six-point functions and collisions in the black hole interior
• Size and momentum of an infalling particle in the black hole interior
• Recovering Infalling Information via String Spreading

Cited by in corpus (7)

• An Outsider's Perspective on Information Recovery in de Sitter Space
• String Stars in Anti de Sitter Space
• Symmetry-resolved modular correlation functions in free fermionic theories
• Tripartite information at long distances
• A Tale of Two Butterflies: An Exact Equivalence in Higher-Derivative Gravity
• Shape dependence of mutual information in the OPE limit: linear responses
• Causal shadow and non-local modular flow: from degeneracy to perturbative genesis by correlation