Quantum Back Flow Across a Black Hole Horizon in a Toy Model Approach
arXiv:2105.03944 · doi:10.1103/PhysRevD.104.104061
Abstract
Quantum Back Flow (QBF), discovered quite a few years back, is a generic purely quantum phenomenon, in which the probability of finding a particle in a direction is non-zero (and increasing for a certain period of time) even when the particle has with certainty a velocity in the opposite direction. In this paper, we study QBF of a quantum particle across the event horizon of a Schwarzschild Black Hole. In a toy model approach, we consider a superposition of two ingoing solutions and observe the probability density and probability current. We explicitly demonstrate a non-vanishing quantum backflow in a small region around the event horizon. This is in contrast to the classical black hole picture, that once an excitation crosses the horizon, it is lost forever from the outside world. Deeper implications of this phenomenon are speculated. We also study quantum backflow for another spacetime with a horizon, the Rindler spacetime, where the phenomenon can be studied only within the Rindler wedge.
arXiv commenttitle changed, expanded version with new figures and explanations, no change in results and conclusions; accepted for publication in PRD
References in corpus (27)
- Average Entropy of a Subsystem
- Fast Scramblers
- The entropy of bulk quantum fields and the entanglement wedge of an evaporating black hole
- The entropy of Hawking radiation
- The scattering matrix approach for the quantum black hole, an overview
- Quantum arrival time measurement and backflow effect
- Black hole unitarity and antipodal entanglement
- A new approach to quantum backflow
- Decoherence of quantum wavepackets due to interaction with conformal spacetime fluctuations
- Analytic Examples, Measurement Models and Classical Limit of Quantum Backflow
- Detecting quantum backflow by the density of a Bose-Einstein Condensate
- An Introduction to the Quantum Backflow Effect
- Quantum Backflow States from Eigenstates of the Regularized Current Operator
- Gravitational Decoherence of Dark Matter
- Quantum backflow in a ring
- Decay of a quasi-stable quantum system and quantum backflow
- Relativistic Quantum Backflow
- Black Hole S-matrix for a scalar field
- Equivalence between quantum backflow and classically forbidden probability flow in a diffraction-in-time problem
- Observation of Accelerating Wave Packets in Curved Space
- Interference of spin-orbit coupled Bose-Einstein condensates
- Experiment-friendly formulation of quantum backflow
- On the experiment-friendly formulation of quantum backflow
- Black Hole Information Problem and Wave Bursts
- On quantum corrections to geodesics in de-Sitter spacetime
- Can Quantum Particles Cross a Horizon?
- Representations of the Dirac wave function in a curved spacetime