Mutual interaction between two separate events

Sebastian Horvat

Abstract Quantum theory implies, and empirical evidence confirms, that while particles can exhibit wave-like behavior in interferometric experiments, this behavior is so limited as not to allow for third- and higher-order interference. The article at hand shows that this possibility-impossibility structure suggests the universal validity of a principle that regulates statistical correlations between spatiotemporally localized events, independently of the nature of the objects that may or may not partake in these events. Roughly, and up to some qualifications, the said principle mandates that any joint influence of m mutually spacelike separated events on another event, be such, that it can be separated by at least $$\lceil \frac{m}{2} \rceil$$ mediating events, and in some cases, by no more than $$\lceil \frac{m}{2} \rceil$$ mediating events. The structure of quantum interference thus teaches us that events can influence each other in a non-separable fashion, but that this non-separability has a certain exactly quantifiable limit.

Noriaki Horiuchi

Kendra Bueley, Luosi Huang, Kensuke Gallock‐Yoshimura +1 more

We investigate the correlation harvesting protocol for mutual information between two Unruh-DeWitt detectors in a static Ba\~nados-Teitelboim-Zanelli black hole spacetime. Here, the effects coming from communication and change in proper separation of the detectors are set to be negligible so that only a black hole affects the extracted mutual information. We find that, unlike the entanglement harvesting scenario, harvested mutual information is zero only when a detector reaches an event horizon, and that although the Hawking effect and gravitational redshift both affect the extraction of mutual information, it is extreme Hawking radiation that inhibits the detectors from harvesting.

Willy Haeberli

Dimitri R. Yafaev

Mingkun Quan, Runhu Li, Zixu Zhao

We investigate the mutual information harvesting of two circularly accelerated detectors that interact with the massless scalar fields near a reflecting boundary. We consider that the two detectors share a common rotational axis with the same acceleration and trajectory radius. As the interdetector separation increases, the mutual information may exhibit oscillatory behavior at large acceleration and small radius. For a fixed radius, a larger acceleration leads to a larger peak value of the mutual information. Near the boundary, the mutual information may oscillate and the maximum can be obtained. As the acceleration increases, the mutual information in a small interdetector separation first increases and then decreases. For an intermediate interdetector separation, the mutual information may oscillate with the increase of acceleration. For a not large interdetector separation, when we take large acceleration and small radius, as the energy gap increases, the mutual information first decreases, then oscillates, and finally goes to zero. The combination of large acceleration and small radius corresponds to the fast rotation, which significantly modifies the vacuum fluctuations of the field, leading to the oscillatory behavior. Furthermore, the oscillation intensifies near the boundary, which indicates that it is related to the coherent superposition of boundary reflections.