1,177 research outputs found
pseudo-bosons in quantum models
We show how some recent models of PT-quantum mechanics perfectly fit into the
settings of pseudo-bosons, as introduced by one of us. Among the
others, we also consider a model of non-commutative quantum mechanics, and we
show that this model too can be described in terms of pseudo-bosons.Comment: In press in Physics Letters
Creating Interdisciplinarity: Grounded Definitions from the College and University Faculty
Definitions of interdisciplinarity often focus on the integration of disciplinary concepts or perspectives. Few definitions, however, are grounded in the work of faculty who conduct interdisciplinary scholarship. To better understand the practice of interdisciplinarity in research and teaching, and its implications for academics' professional lives, I interviewed college and university faculty affiliated with a variety of liberal arts and sciences disciplines in four U.S. institutions of varying size and mission. The study explored how interviewees practiced interdisciplinarity; how institutional, departmental, and disciplinary locations affected their scholarly identities, professional associations, and work lives; and the kinds of rewards they reaped from interdisciplinary work. In this article, I analyze a subset of the interviews, examining explicit and implied definitions of interdisciplinarity and their relationship to faculty members' understandings of disciplinarity and scholarly work. The analysis reveals that definitions of interdisciplinarity that emphasize integration exclude some forms of interdisciplinary work. I therefore suggest an alternative, more inclusive conceptualization that strives to encompass a range of interdisciplinary practices. Further study of interdisciplinary research and teaching might confirm that all interdisciplinary scholarship can be categorized according to the typology described here - or it might provide evidence of additional forms of interdisciplinarity
Non-Hermitian Hamiltonian for a Modulated Jaynes-Cummings Model with PT Symmetry
We consider a two-level system such as a two-level atom, interacting with a
cavity field mode in the rotating wave approximation, when the atomic
transition frequency or the field mode frequency is periodically driven in
time. We show that in both cases, for an appropriate choice of the modulation
parameters, the state amplitudes in a generic {-}excitation subspace obey
the same equations of motion that can be obtained from a \emph{static}
non-Hermitian Jaynes-Cummings Hamiltonian with symmetry, that
is with an imaginary coupling constant. This gives further support to recent
results showing the possible physical interest of symmetric
non-Hermitian Hamiltonians. We also generalize the well-known diagonalization
of the Jaynes-Cummings Hamiltonian to the non-Hermitian case in terms of
pseudo-bosons and pseudo-fermions, and discuss relevant mathematical and
physical aspects.Comment: 9 page
An architectural generative design process
The paper discusses about architectural and urban design tools, and reports a prototype of parametric application that allows the designer to handle the architectural shape by using urban regulations. It is a Decision Support System (DSS), useful at the early stage of city planning as well as at the early stage of architectural design. The System integrates two different research topics: modelling in geo-referenced environment and modelling through constraints. Compared to the related works (Building Modelling on geo-referenced environment), our application is the first Generative System based on the urban regulation. Three case studies are presented to test the System
Van der Waals and resonance interactions between accelerated atoms in vacuum and the Unruh effect
We discuss different physical effects related to the uniform acceleration of
atoms in vacuum, in the framework of quantum electrodynamics. We first
investigate the van der Waals/Casimir-Polder dispersion and resonance
interactions between two uniformly accelerated atoms in vacuum. We show that
the atomic acceleration significantly affects the van der Waals force, yielding
a different scaling of the interaction with the interatomic distance and an
explicit time dependence of the interaction energy. We argue how these results
could allow for an indirect detection of the Unruh effect through dispersion
interactions between atoms. We then consider the resonance interaction between
two accelerated atoms, prepared in a correlated Bell-type state, and
interacting with the electromagnetic field in the vacuum state, separating
vacuum fluctuations and radiation reaction contributions, both in the
free-space and in the presence of a perfectly reflecting plate. We show that
nonthermal effects of acceleration manifest in the resonance interaction,
yielding a change of the distance dependence of the resonance interaction
energy. This suggests that the equivalence between temperature and acceleration
does not apply to all radiative properties of accelerated atoms. To further
explore this aspect, we evaluate the resonance interaction between two atoms in
non inertial motion in the coaccelerated (Rindler) frame and show that in this
case the assumption of an Unruh temperature for the field is not required for a
complete equivalence of locally inertial and coaccelerated points of views.Comment: 8 pages, Proceedings of the Eighth International Workshop DICE 2016
Spacetime - Matter - Quantum Mechanic
Non-thermal effects of acceleration in the resonance interaction between two uniformly accelerated atoms
We study the resonance interaction between two uniformly accelerated
identical atoms, one excited and the other in the ground state, prepared in a
correlated (symmetric or antisymmetric) state and interacting with the scalar
field or the electromagnetic field in the vacuum state. In this case (resonance
interaction), the interatomic interaction is a second-order effect in the
atom-field coupling. We separate the contributions of vacuum fluctuations and
radiation reaction to the resonance energy shift of the system, and show that
only radiation reaction contributes, while Unruh thermal fluctuations do not
affect the resonance interaction. We also find that beyond a characteristic
length scale related to the atomic acceleration, non-thermal effects in the
radiation reaction contribution change the distance-dependence of the resonance
interaction. Finally, we find that previously unidentified features appear,
compared with the scalar field case, when the interaction with the
electromagnetic field is considered, as a consequence of the peculiar nature of
the vacuum quantum noise of the electromagnetic field in a relativistically
accelerated background.Comment: 10 page
The Urban Agriculture Programme of the Municipality of Rosario, Argentina
El Programa de Agricultura Urbana de Rosario (en adelante PAU) surge como política municipal en respuesta a la crisis argentina de 2001. Desde entonces ha vivido distintas etapas de desarrollo, hasta su consolidación como política pública de desarrollo municipal y su inserción en el plan de ordenamiento territorial. En este proceso, el PAU ha creado nuevos espacios públicos socio-productivos para la ciudad como Parques Huertas, corredores verdes de las vías y Huertas jardines saludables. A continuación se explican las etapas vividas por el PAU desde su creación hasta la actualidad, así como las actuales línea de trabajo
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