General relativistic Poynting-Robertson effect to diagnose wormholes existence: static and spherically symmetric case

We derive the equations of motion of a test particle in the equatorial plane around a static and spherically symmetric wormhole influenced by a radiation field including the general relativistic Poynting-Robertson effect. From the analysis of this dynamical system, we develop a diagnostic to distinguish a black hole from a wormhole, which can be timely supported by several and different observational data. This procedure is based on the possibility of having some wormhole metrics, which smoothly connect to the Schwarzschild metric in a small transition surface layer very close to the black hole event horizon. To detect such a metric-change, we analyse the emission proprieties from the critical hypersurface (stable region where radiation and gravitational fields balance) together with those from an accretion disk in the Schwarzschild spacetime toward a distant observer. Indeed, if the observational data are well fitted within such model, it immediately implies the existence of a black hole; while in case of strong departures from such description it means that a wormhole could be present. Finally, we discuss our results and draw the conclusions.Comment: 17 pages, 11 figures, 1 Table. Paper accepted on April 30, 2020 on Physical Review

Heat flux dynamics in dissipative cascaded systems

We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.Comment: Final accepted versio

Impact of Structural Health Monitoring on Aircraft Operating Costs by Multidisciplinary Analysis

Structural health monitoring is recognized as a viable solution to increase aviation safety and decrease operating costs enabling a novel maintenance approach based on the actual condition of the airframe, mitigating operating costs induced by scheduled inspections. However, the net benefit is hardly demonstrated, and it is still unclear how the implementation of such an autonomic system can affect performance at aircraft level. To close this gap, this paper presents a systematic analysis where the impact of cost and weight of integrating permanently attached sensors-used for diagnostics- affect the main performance of the aircraft. Through a multidisciplinary aircraft analysis framework, the increment of aircraft operating empty weight is compared with the possible benefits in terms of direct operating costs to identify a breakeven point. Furthermore, the analysis allows to establish a design guideline for structural health monitoring systems returning a safer aircraft without any economic penalties. The results show that the operating costs are lower than those of the reference aircraft up to 4% increase in maximum take-off weight. Paper findings suggest to considering a condition monitoring strategy from the conceptual design stage, since it could maximize the impact of such innovative technology. However, it involves in a design of a brand-new aircraft instead of a modification of an existing one

Potential Benefit of Structural Health Monitoring System on Civil Jet Aircraft

Structural health monitoring represents an interesting enabling technology towards increasing aviation safety and reducing operating costs by unlocking novel maintenance approaches and procedures. However, the benefits of such a technology are limited to maintenance costs reductions by cutting or even eliminating some maintenance scheduled checks. The key limitation to move a step further in exploiting structural health monitoring technology is represented by the regulation imposed in sizing aircraft composite structures. A safety margin of 2.0 is usually applied to estimate the ultimate loading that composite structures must withstand. This limitation is imposed since physical nondestructive inspection of composite structures is really challenging or even impossible in some cases. However, a structural health monitoring system represents a viable way for a real time check for the health status of a composite structure. Thus, the introduction of structural health monitoring should help into reducing the stringent safety margin imposed by aviation regulation for a safe design of composite structures. By assuming a safety margin reduction from 2.0 to 1.75 thanks to the installation of permanently attached sensors for structural health diagnostics, this paper assesses the potential fuel savings and direct operating costs through a multidisciplinary analysis on a A220-like aircraft. According to the foreseen level of technology, addressed through the number of sensors per square meter, a DOC saving from 2% up to 5% is achievable preserving, at the same time, all the key aircraft performance

remarks on a computational estimator for the barrier option pricing in an iot scenario

Abstract The importance of derivatives in financial markets has known an exponential growth in the last decades, especially in risk management and speculation fields: this explains researchers' interest in answering questions about this kind of contracts. In particular, in this paper we restrict our attention on European vanilla and barrier options, and we propose a statistical procedure to solve efficiently the problem of determining the no arbitrage price of this type of derivatives in an IoT context: starting form an Internet of Things (IoT) data flow, an IoT system takes information from several sources and stores it into a suitable database; this information is used in our estimation problem. Our scheme is based on some strong assumptions about the market model, in particular the completeness of the market, the log-normality of the underlying asset with a constant volatility. We conclude this paper with an application of our framework to a real case

analysis of a data flow in a financial iot system

Abstract Data retrieving, analysis e management are usually known as complex task in financial contexts. In an Internet of Things (IoT) system data-flow processes represent the knowledge base used in mathematical models for credits and financial products. Several sources such as distributed database systems, portals and local information are generally used as input of inferring models. In this paper we describe an overview of software tools, methodologies and strategies in real data-flow system

The role of the boundary term in f(Q,B)f(Q,B) symmetric teleparallel gravity

In the framework of metric-affine gravity, we consider the role of the boundary term in Symmetric Teleparallel Gravity assuming $f(Q,B)$ models where $f$ is a smooth function of the non-metricity scalar $Q$ and the related boundary term $B$. Starting from a variational approach, we derive the field equations and compare them with respect to those of $f(Q)$ gravity in the limit of $B\to0$. It is possible to show that $f(Q,B)=f(Q-B)$ models are dynamically equivalent to $f(R)$ gravity as in the case of teleparallel $f(\tilde{B}-T)$ gravity (where $B\neq \tilde{B}$). Furtherrmore, conservation laws are derived. In this perspective, considering boundary terms in $f(Q)$ gravity represents the last ingredient towards the Extended Geometric Trinity of Gravity where $f(R)$, $f(T,\tilde{B})$ and $f(Q,B)$ can be dealt under the same standard.Comment: 7 pages, 1 figur

The relationship among the health-related quality of life, illness severity, personality and psychiatric symptoms in patients with psoriasis: an empirical investigation

Background: Psoriasis is a complex and chronic inflammatory skin disorder. The mechanisms underlying this immune-mediated disease are not clear, but some evidence indicates that specific personality features and symptom patterns may play an important role in the development and clinical presentation of the disorder and influence the quality of patients’ lives. This study aimed at evaluating the associations among the quality of life, illness severity, psychiatric symptoms and personality patterns in patients with psoriasis treated with biological or topical therapy. Methods: Fifty psoriatic patients were evaluated with self-report measures: the Symptom Checklist-90-R (SCL-90R) and the Psoriasis Index of Quality of Life (PSORIQoL). Their personality and psychological functioning were assessed by external raters using the Shedler-Westen Assessment Procedure (SWAP-200) applied to the Clinical Diagnostic Interviews (CDI). Finally, the severity and the area of psoriatic lesions were evaluated by dermatologists with the Psoriasis Area Severity Index (PASI). Results: Significant differences between the groups (biological vs topical therapy) were found in PASI scores: patients assigned to biological therapy showed lower levels of illness severity. No differences were found in PSORIQoL scores. The quality of life was negatively associated with various dimensions of SCL-90R and with borderline (r = .39; p< .01), dependent (r = .41; p< .01) and avoidant (r = .35; p< .05) personality styles/disorders; conversely, it did not relate to PASI. Conclusions: The results seem to suggest that the quality of life in psoriatic patients is more influenced by personality characteristics and psychiatric symptoms than by the severity of psoriatic lesions

Quantum work extraction efficiency for noisy quantum batteries: the role of coherence

Quantum work capacitances and maximal asymptotic work/energy ratios are figures of merit characterizing the robustness against noise of work extraction processes in quantum batteries formed by collections of quantum systems. In this paper we establish a direct connection between these functionals and, exploiting this result, we analyze different types of noise models mimicking self-discharging, thermalization and dephasing effects. In this context we show that input quantum coherence can significantly improve the storage performance of noisy quantum batteries and that the maximum output ergotropy is not always achieved by the maximum available input energy.Comment: 16 pages, 8 figure