Nonlocal properties of dynamical three-body Casimir-Polder forces

We consider the three-body Casimir-Polder interaction between three atoms during their dynamical self-dressing. We show that the time-dependent three-body Casimir-Polder interaction energy displays nonlocal features related to quantum properties of the electromagnetic field and to the nonlocality of spatial field correlations. We discuss the measurability of this intriguing phenomenon and its relation with the usual concept of stationary three-body forces.Comment: 4 page

Vacuum field correlations and three-body Casimir-Polder potential with one excited atom

The three-body Casimir-Polder potential between one excited and two ground-state atoms is evaluated. A physical model based on the dressed field correlations of vacuum fluctuations is used, generalizing a model previously introduced for three ground-state atoms. Although the three-body potential with one excited atom is already known in the literature, our model gives new insights on the nature of non-additive Casimir-Polder forces with one or more excited atoms.Comment: 9 page

An Exploration of the Impact of Mapping Style and Device Roadmap on Simulated ReRAM Architectures for Neuromorphic Computing

This paper investigates the relationship between mapping style and device roadmap in Resistive Random Access Memory (ReRAM) architectures for neuromorphic computing. The study leverages simulations using DNN+NeuroSim to evaluate the impact of different parameters on chip performance, including latency, energy consumption, and overall system efficiency. The results demonstrate that novel mapping techniques and a high-performance (HP) device roadmap are optimal if energy and speed considerations are weighted equally. This is because as the study demonstrates, HP devices provide a latency cut that outsizes the energy cost. Additionally, adopting novel mapping in the device cuts latency by nearly 30% while being slightly more energy efficient. The findings highlight the importance of considering mapping style and device roadmap in optimizing ReRAM architectures for neuromorphic computing, which may contribute to advancing the practical implementation of ReRAM in computational systems

Dynamical Casimir-Polder energy between an excited and a ground-state atom

We consider the Casimir-Polder interaction between two atoms, one in the ground state and the other in its excited state. The interaction is time-dependent for this system, because of the dynamical self-dressing and the spontaneous decay of the excited atom. We calculate the dynamical Casimir-Polder potential between the two atoms using an effective Hamiltonian approach. The results obtained and their physical meaning are discussed and compared with previous results based on a time-independent approach which uses a non-normalizable dressed state for the excited atom.Comment: 11 page

Electrons on a spherical surface: Physical properties and hollow spherical clusters

We discuss thephysical properties of a non interacting electron gas constrained to a spherical surface. In particular we consider its chemical potentials, its ionization potential,and its electric static polarizability. All these properties are discussed analytically as functions of the number N of electrons. The trends obtained with increasing N are compared with those of the corresponding properties experimentally measured or theoretically evaluated for quasi spherical hollow atomic and molecular clusters. Most of the properties investigated display similar trends, characterized by a prominence of shell effects. This leads to the de\ufb01nition of a scale-invariant distribution of magic numbers which follows a power law with critical exponent 120.5. We conclude that our completely mechanistic and analytically tractable model can be useful for the analysis of self-assembling complex systems

Organizational models in robotica assisted surgery

The development and diffusion of minimally-invasive surgery has been possible due to the application of new technologies, including robotics, which has only recently been introduced in this field. The aim of the study was to propose a series of guidelines regarding the organizational and didactic requirements for ensuring high operative standards for the diffusion of robotic surgery. Problems concerning installation of the robotic system, disposition of the operating room, and standardization of surgical procedures are discussed. To exemplify these aspects, the phases of a robotic cholecystectomy are described. The essential requirements for the creation of training and research centers for robotic surgery are outlined. In addition, the ideal course of training for the surgeon of the third millennium is delineated. In the near future, robotic technique is destined to play an increasingly important role, both in general surgery and in the surgical specialties. The development of special centers for the diffusion and teaching of robotic surgery, therefore, is an objective to be pursued

The role of micronutrients in support of the immune response against viral infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19)

Electromagnetic inversion for subsurface applications under the distorted Born approximation

The problem of reconstructing dielectric permittivity of a buried object from the knowledge of the scattered field is considered for a two-dimensional rectangular geometry at a fixed frequency. The linearization of the mathematical relationship between the dielectric permittivity function and the scattered field about a constant reference profile function and the approximation of actual internal field with the unperturbed field leads to the so-called Distorted Born Approximation. To analyze the limitations and capabilities of the linear inversion algorithms, we investigate the class of the retrievable profiles. This analysis makes it possible to point out that a very reduced number of independent data is available, so requiring to employ regularization techniques in order to perform in a reliable and stable way the linear inversions. In this paper we present a general algorithm consisting in a regularized Singular Value Decomposition of the matrix resulting from a discretization of the problem. Finally, numerical results of linear inversions are given

The limits of the rotating wave approximation in the electromagnetic field propagation in a cavity

We consider three two-level atoms inside a one-dimensional cavity, interacting with the electromagnetic field in the rotating wave approximation (RWA), commonly used in the atom-radiation interaction. One of the three atoms is initially excited, and the other two are in their ground state. We numerically calculate the propagation of the field spontaneously emitted by the excited atom and scattered by the second atom, as well as the excitation probability of the second and third atom. The results obtained are analyzed from the point of view of relativistic causality in the atom-field interaction. We show that, when the RWA is used, relativistic causality is obtained only if the integrations over the field frequencies are extended to $-\infty$; on the contrary, noncausal tails remain even if the number of field modes is increased. This clearly shows the limit of the RWA in dealing with subtle problems such as relativistic causality in the atom-field interaction.Comment: 13 pages, 6 figure