42,216 research outputs found
Klein-Gordon Oscillator in Kaluza-Klein Theory
In this contribution we study the Klein-Gordon oscillator on the curved
background within the Kaluza-Klein theory. The problem of interaction between
particles coupled harmonically with a topological defects in Kaluza-Klein
theory is studied. We consider a series of topological defects, that treat the
Klein-Gordon oscillator coupled to this background and find the energy levels
and corresponding eigenfunctions in these cases. We show that the energy levels
depend on the global parameters characterizing these spacetimes. We also
investigate a quantum particle described by the Klein-Gordon oscillator
interacting with a cosmic dislocation in Som-Raychaudhuri spacetime in the
presence of homogeneous magnetic field in a Kaluza-Klein theory. In this case,
the spectrum of energy is determined, and we observe that these energy levels
are the sum of the term related with Aharonov-Bohm flux and of the parameter
associated to the rotation of the spacetime.Comment: 15 pages, no figur
Renormalization in the Henon family, I: universality but non-rigidity
In this paper geometric properties of infinitely renormalizable real
H\'enon-like maps in are studied. It is shown that the appropriately
defined renormalizations converge exponentially to the one-dimensional
renormalization fixed point. The convergence to one-dimensional systems is at a
super-exponential rate controlled by the average Jacobian and a universal
function . It is also shown that the attracting Cantor set of such a map
has Hausdorff dimension less than 1, but contrary to the one-dimensional
intuition, it is not rigid, does not lie on a smooth curve, and generically has
unbounded geometry.Comment: 42 pages, 5 picture
Endurant Types in Ontology-Driven Conceptual Modeling: Towards OntoUML 2.0
For over a decade now, a community of researchers has contributed
to the development of the Unified Foundational Ontology (UFO)
- aimed at providing foundations for all major conceptual modeling constructs.
This ontology has led to the development of an Ontology-Driven
Conceptual Modeling language dubbed OntoUML, reflecting the ontological
micro-theories comprising UFO. Over the years, UFO and OntoUML
have been successfully employed in a number of academic, industrial and
governmental settings to create conceptual models in a variety of different
domains. These experiences have pointed out to opportunities of
improvement not only to the language itself but also to its underlying
theory. In this paper, we take the first step in that direction by revising
the theory of types in UFO in response to empirical evidence. The
new version of this theory shows that many of the meta-types present
in OntoUML (differentiating Kinds, Roles, Phases, Mixins, etc.) should
be considered not as restricted to Substantial types but instead should
be applied to model Endurant Types in general, including Relator types,
Quality types and Mode types. We also contribute a formal characterization
of this fragment of the theory, which is then used to advance a
metamodel for OntoUML 2.0. Finally, we propose a computational support
tool implementing this updated metamodel
Holonomy Transformation in the FRW Metric
In this work we investigate loop variables in Friedman-Robertson-Walker
spacetime. We analyze the parallel transport of vectors and spinors in several
paths in this spacetime in order to classify its global properties. The band
holonomy invariance is analysed in this background.Comment: 8 page
Three-dimensional quantum electrodynamics as an effective interaction
We obtain a Quantum Electrodynamics in 2+1 dimensions by applying a
Kaluza--Klein type method of dimensional reduction to Quantum Electrodynamics
in 3+1 dimensions rendering the model more realistic to application in
solid-state systems, invariant under translations in one direction. We show
that the model obtained leads to an effective action exhibiting an interesting
phase structure and that the generated Chern--Simons term survives only in the
broken phase.Comment: 10 pages in Plain Te
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