1,720,996 research outputs found
Probing the non-Planckian spectrum of thermal radiation in a micron-sized cavity with a spin-polarized atomic beam
No full textApparatus to probe the influence of the Mott-Anderson metal-insulator transition in doped semiconductors on the Casimir effect
No full textTopological approach to historical analytic narrative in the ‘Game Theory lab’ activities
No full textSurface Scattering Expansion of the Casimir–Polder Interaction for Magneto-Dielectric Bodies: Convergence Properties for Insulators, Conductors, and Semiconductors
Full text linkFluctuation-induced forces are a hallmark of the interplay between fluctuations and geometry. We recently proved the existence of a multi-parametric family of exact representations of Casimir and Casimir–Polder interactions between bodies of arbitrary shape and material composition, admitting a multiple scattering expansion (MSE) as a sequence of inter-body and intra-body multiple wave scatterings. The approach requires no knowledge of the scattering amplitude (T-matrix) of the bodies. In this paper, we investigate the convergence properties of the MSE for the Casimir–Polder interaction of a polarizable particle with a macroscopic body. We consider representative materials from different classes, such as insulators, conductors, and semiconductors. Using a sphere and a cylinder as benchmarks, we demonstrate that the MSE can be used to efficiently and accurately compute the Casimir–Polder interaction for bodies with smooth surfaces
Casimir-Polder shift of ground-state hyperfine Zeeman sublevels of hydrogen isotopes in a micron-sized metallic cavity at finite temperature
No full textThe frequencies of transitions between hyperfine levels of ground-state atoms can be measured with exquisite precision using magnetic-resonance techniques. This makes hyperfine transitions ideal probes of QED effects originating from the interaction of atoms with the quantized electromagnetic field. One of the most remarkable effects predicted by QED is the Casimir-Polder shift experienced by the energy levels of atoms placed near one or more dielectric objects. Here we compute the Casimir-Polder shift and the width of hyperfine transitions between ground-state Zeeman sublevels of a hydrogen atom placed in a micron-sized metallic cavity, over a range of temperatures extending from cryogenic temperatures to room temperature. Results are presented also for deuterium and tritium. We predict shifts of the hyperfine transitions frequencies of a few tens of Hz that might be measurable with present-day magnetic resonance apparatus
Economics and mathematics: a transdisciplinary path using geodynamical models and computational software
No full textPeierls brackets: from field theory to dissipative systems
No full textPeierls brackets are part of the space-time approach to quantum field theory,
and provide a Poisson bracket which, being defined for pairs of observables which are group
invariant, is group invariant by construction. It is therefore well suited for combining the
use of Poisson brackets and the full diffeomorphism group in general relativity. The present
paper provides at first an introduction to the topic, with applications to gauge field theory.
In the second part, a set of brackets for classical dissipative systems, subject to external
random forces, are derived. The method is inspired by the old procedure of Peierls, for
deriving the canonical brackets of conservative systems, starting from an action principle. It
is found that an adaptation of Peierls’ method is applicable also to dissipative systems, when
the friction term can be described by a linear functional of the coordinates, as is the case in
the classical Langevin equation, with an arbitrary memory function. The general expression
for the brackets satisfied by the coordinates, as well as by the external random forces, at
different times, is determined, and it turns out that they all satisfy the Jacobi identity.
Upon quantization, these classical brackets are found to coincide with the commutation
rules for the quantum Langevin equation, that have been obtained in the past, by appealing
to microscopic conservative quantum models for the friction mechanism
Chapter 11 “Game Theory Lab”:. A Gamification Laboratory for High School Students
No full textTo exploit the tendency ofstudentsto get excitedwhen they have to solve competitive games and introduce
them to solve complex problems in real situations, the Departments of Mathematics and Economics of
the University of Salerno devised a technological educational project, the Theory of Games Lab (GTL),
for high school students. GTL helps students understand an abstract model that requires the use of
mathematical analysis in economics, creating an engaging learning environment that improves their
performance and rewards cooperative behavior. The choice of games is applied to the construction of a
reward-based to engage in class discussions also using educational games sites. Technological artifacts
are semiotic mediators in a constructivist approach. With a simulated role-playing game, students are
landowners in medieval times and protect their lands by confronting the challenges and needs of other
territories. At the end of the activities, the students have a better attitude for critical analysis of economic
phenomena and are interested in issues never addressed befor
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