Search results for "46"
showing 10 items of 1176 documents
Neutrino pair annihilation ( $$\nu {\bar{\nu }}\rightarrow e^-e^+$$ ν ν ¯ → e - e + ) in the presence of quintessence surrounding a black hole
2021
Quintessence fields, introduced to explain the speed-up of the Universe, might affect the geometry of spacetime surrounding black holes, as compared to the standard Schwarzschild and Kerr geometries. In this framework, we study the neutrino pairs annihilation into electron-positron pairs ($\nu{\bar \nu}\to e^-e^+$) near the surface of a neutron star, focusing, in particular, on the Schwarzschild-like geometry in presence of quintessence fields. The effect of the latter is to increase the minimum photon-sphere radius ($R_{ph}$), increasing in such a way the maximum energy deposition rate near to $R_{ph}$. The rate turns out to be several orders of magnitude greater than the rate computed in …
Sterile Neutrinos, Black Hole Vacuum and Holographic Principle
2021
We construct an effective field theory (EFT) model that describes matter field interactions with Schwarzschild mini-black-holes (SBH's), treated as a scalar field, $B_0(x)$. Fermion interactions with SBH's require a random complex spurion field, $\theta_{ij}$, which we interpret as the EFT description of "holographic information," which is correlated with the SBH as a composite system. We consider Hawking's virtual black hole vacuum (VBH) as a Higgs phase, $\langle B_0 \rangle =V$. Integrating sterile neutrino loops, the field $\theta_{ij}$ is promoted to a dynamical field, necessarily developing a tachyonic instability and acquiring a VEV of order the Planck scale. For $N$ sterile neutrino…
Quark structure of the $$\chi _{\mathrm{c}}(3P)$$ χc(3P) and X(4274) resonances and their strong and radiative decays
2020
We calculate the masses of $$\chi _{\mathrm{c}}(3P)$$ χc(3P) states with threshold corrections in a coupled-channel model. The model was recently applied to the description of the properties of $$\chi _{\mathrm{c}}(2P)$$ χc(2P) and $$\chi _{\mathrm{b}}(3P)$$ χb(3P) multiplets (Ferretti and Santopinto in Phys Lett B 789:550, 2019]. We also compute the open-charm strong decay widths of the $$\chi _{\mathrm{c}}(3P)$$ χc(3P) states and their radiative transitions. According to our predictions, the $$\chi _{\mathrm{c}}(3P)$$ χc(3P) states should be dominated by the charmonium core, but they may also show small meson-meson components. The X(4274) is interpreted as a $$c {{\bar{c}}}$$ cc¯ $$\chi _…
Gender Diversity in STEM Disciplines: A Multiple Factor Problem.
2019
La falta de diversidad, y específicamente de diversidad de género, es uno de los problemas clave que se están encontrando tanto las empresas del sector tecnológico como las instituciones del ámbito académico en la educación superior. Según la UNESCO, las mujeres representan el 35% de todos los matriculados en las ramas de Ciencia, Tecnología, Ingeniería y Matemáticas (STEM, en sus siglas en inglés), encontrándose el mínimo, un 3%, en el área de las Tecnologías de la Información y las Comunicaciones (TIC). Al mismo tiempo, el número de mujeres profesionales que abandonan trabajos de perfil tecnológico es inaceptablemente alto. Como miembros de una institución de educación superior centrada e…
An Anthropological Insight on the Commonalities between Tourism and Archaeology
2019
Over the years, archaeology maturated towards something else than a scientific discipline. Archaeological sites are culturally showed as emerging and recycled tourist attractions (Robb 1998; Bateman 2006; Rowan & Baram 2004; Karlsson & Gustafsson, 2006). At a closer look, tourism is understood as a leisure activity which is enrooted in the needs of relaxing and evasion while archaeology -as a knowledge platform which is based on scientific method- explores the history of ancient cultures. This raises a more than interesting question respecting the commonalities and differences between archaeology and tourism. To some extent, archaeologists find ancient relics and objects whi…
La festa barocca a Palermo : città, architetture, istituzioni
2006
La festa barocca a Palermo costituisce l’alter ego effimero e occasionale del processo di monumentalizzazione, graduale e complesso, della città: entrambi obbediscono alle stesse esigenze di ufficialità e magnificenza, da soddisfare obbligatoriamente nell’ottica di una città capitale. L’autorevole regista delle grandi manifestazioni ufficiali è il Senato palermitano, al quale come massima istituzione della città è affidata in genere la responsabilità sia dell’organizzazione materiale, sia dell’elaborazione culturale del programma celebrativo, in particolare della festa annuale in onore di S. Rosalia.In Palermo the baroque festival is the ephemeral and occasional alter ego of monumentalisati…
Pietro Antonio Tomasello de Padua : un ingeniero militar véneto en la Sicilia de Carlos V
2011
En 1522 el virrey de Sicilia, Ettore Pignatelli, conde de Monteleone, inició una gran campaña para fortalecer las defensas de las principales ciudades de la costa de Sicilia: Palermo, Trapani, Milazzo, Siracusa y, algunos años más tarde, incluso Messina. El ingeniero real Pietro Antonio Tomasello de Padua, un técnico militar Veneto, pidió renovar el sistema de defensas de la isla, con la introducción por primera vez de bastiones circulares y poligonales en fortalezas y murallas de la ciudad. La obra, desconocida hasta ahora, de este importante ingeniero militar activo en Sicilia desde 1523 hasta 1537, año de su muerte, está siendo reconstruida con una importante documentación de archivo. La…
Virtual Tours as Emerging Technologies to Engage Children and Youth with their Country’s Historical Conflicts
2022
Virtual Reality (VR) is increasingly used for visiting historic places. Research on VR experiences in dark tourism (that focuses on mortality) focuses almost exclusively on adults. No studies were found that used virtual tours to engage children with their own country’s conflicts. The present study addresses this gap by designing and developing virtual tours in four cities of Europe with a troubled past. Virtual tours engage children and youth in historical conflicts using multi-perspective storytelling. The aim of this pre-test post-test comparative case study is to examine the change on students’ perceptions of their country’s troubled past after their interaction with a virtual tour of t…
Social Influence Maximization in Hypergraphs
2021
This work deals with a generalization of the minimum Target Set Selection (TSS) problem, a key algorithmic question in information diffusion research due to its potential commercial value. Firstly proposed by Kempe et al., the TSS problem is based on a linear threshold diffusion model defined on an input graph with node thresholds, quantifying the hardness to influence each node. The goal is to find the smaller set of items that can influence the whole network according to the diffusion model defined. This study generalizes the TSS problem on networks characterized by many-to-many relationships modeled via hypergraphs. Specifically, we introduce a linear threshold diffusion process on such …
Psychomotor approach in children affected by nonretentive fecal soiling (FNRFS): A new rehabilitative purpose
2013
Maria Esposito,1 Francesca Gimigliano,1,2 Maria Ruberto,2 Rosa Marotta,3 Beatrice Gallai,4 Lucia Parisi,5 Serena Marianna Lavano,3 Giovanni Mazzotta,6 Michele Roccella,5 Marco Carotenuto1 1Center for Childhood Headache, Clinic of Child and Adolescent Neuropsychiatry, Department of Mental Health, Physical and Preventive Medicine, Second University of Naples, Naples, Italy; 2Department of Odontostomathologic Disciplines, Head Pathology, Orthopedic Sciences, Second University of Naples, Italy; 3Department of Psychiatry, Magna Graecia University of Catanzaro, Catanzaro, Italy; 4Unit of Child and Adolescent Neuropsychiatry, University of Perugia, Perugia, Italy; 5Child Neuropsychiatry, Departmen…