arXiv subjects

João G. A. Caribé

Publications and source records attributed to João G. A. Caribé.

3 recordsLinked to original sources

arXiv2025

Mass Dependence of the Araki-Uhlmann Relative Entropy Across Dimensions

We investigate the mass dependence of the Araki-Uhlmann relative entropy between a localized coherent excitation and the vacuum state of a free scalar quantum field on the $(1+d)$-dimensional Minkowski spacetime for $d = 1, 2, 3$. In this context, the relative entropy admits a closed expression in terms of the smeared Pauli-Jordan distribution, whose analytic structure is sensitive to both the mass and the spacetime dimensionality. Prior studies in $(1+1)$ dimensions have shown a monotonic decay of the relative entropy with increasing mass. We extend that analysis to higher dimensions using numerical techniques and elucidate how the interplay between dimensionality and mass controls the behavior of the relative entropy. Our results provide new insights for the study of the Araki-Uhlmann relative entropy in QFT and its dependence on physical parameters.

hep-th↗

arXiv2025

Investigating the Araki-Uhlmann relative entropy between two coherent states in relativistic Quantum Field Theory

A numerical setup for investigating the Araki-Uhlmann relative entropy between two coherent states is presented for a scalar massive Quantum Field Theory in ($1+1$)-dimensional Minkowski spacetime. These states are constructed using smeared Weyl operators compactly supported in two diamond regions belonging to the right Rindler wedge. Using this setup, we verified the known properties of the relative entropy, namely: positivity, increase with the size of the spacetime regions considered, decrease with the increase of the mass parameter. A linear increase with respect to the spatial distance between the two diamond regions is also observed.

hep-th↗

arXiv2023

Lensing of Vacuum Entanglement near Schwarzschild Black Holes

An important feature of Schwarzschild spacetime is the presence of orbiting null geodesics and caustics. Their presence implies strong gravitational lensing effects for matter and radiation, i.e., for excitations of quantum fields. Here, we raise the question whether the lensing manifests itself also in the vacuum of quantum fields, namely by lensing the distribution of vacuum entanglement. To explore this possibility, we use the method of entanglement harvesting, where initially unentangled localized quantum systems are temporarily coupled to the field at different locations. We find that for the Boulware, Hartle-Hawking and Unruh vacua in 3+1 dimensional Schwarzschild spacetime, the harvesting of vacuum entanglement is indeed greatly amplified near caustics. In particular, we establish that pre-existing vacuum entanglement can be harvested also for lightlike separations.

quant-ph↗