15,031 research outputs found
On the Zitterbewegung Transient Regime in a Coarse-Grained Space-Time
In the present contribution, by studying a fractional version of Dirac's
equation for the electron, we show that the phenomenon of Zitterbewegung in a
coarse-grained medium exhibits a transient oscillatory behavior, rather than a
purely oscillatory regime, as it occurs in the integer case, . Our
result suggests that, in such systems, the Zitterbewegung-type term related to
a trembling motion of a quasiparticle is tamed by its complex interactions with
other particles and the medium. This can justify the difficulties in the
observation of this interesting phenomenon. The possibility that the
Zitterbewegung be accompanied by a damping factor supports the viewpoint of
particle substructures in Quantum Mechanics.Comment: 11 pages, 1 figure. This paper has been published in J. Adv. Phys. 7
(2015) 144
Remarks on nonlinear Electrodynamics
We consider both generalized Born-Infeld and Exponential Electrodynamics. The
field-energy of a point-like charge is finite only for Born-Infeld-like
Electrodynamics. However, both Born-Infeld-type and Exponential Electrodynamics
display the vacuum birefringence phenomenon. Subsequently, we calculate the
lowest-order modifications to the interaction energy for both classes of
Electrodynamics, within the framework of the gauge-invariant path-dependent
variables formalism. These are shown to result in long-range (- type)
corrections to the Coulomb potential. Once again, for their non-commutative
versions, the interaction energy is ultraviolet finite.Comment: 10 pages. arXiv admin note: substantial text overlap with
arXiv:1312.515
Representing Roomates' Preferences with Symmetric Utilities
In the context of the stable roommates problem, it is shown that acyclicity of preferences is equivalent to the existence of symmetric utility functions, i.e. the utility of agent i when matched with j is the same as j 's utility when matched with i .
Creativity and innovation: A contribution of behavioral economics
Innovation in products and services is seen by scholars, by specialized media in management, and by some managers as the main currency in modern economies. This is
because it allows high average market profits, fame for innovators, or brand growth, for example. However, in practice, most managers still treat innovation as a secondary issue
on their agendas. This problem results from the inability of market professionals to analyze people inside and outside their companies. It is not possible to develop innovative products in a systematic way without treating this point effectively. Moreover, in this process, creativity is a necessary, but not necessarily sufficient, condition to be fulfilled and requires
behavioral transformation. In this context, it is believed that behavioral economics can
make a sufficient contribution in the form of an analytical marketing tool by offering an
analysis closer to human beings' reality, and, thus, allow a better understanding of people's behavior in the process of innovation in the market
Topological Gravity on Shift Superspace Formulation
In this contribution, we re-assess the subject of topological gravity by
following the Shift Supersymmetry formalism. The gauge-fixing of the theory
goes under the Batallin-Vilkovisky (BV) prescription based on a diagram that
contains both ghost and anti-ghost superfields, associated to the
super-vielbein and the super-Lorentz connection. We extend the formulation of
the topological gravity action to an arbitrary number of dimensions of the
shift superspace by adopting a formulation based on the gauge-fixing for
BF-type models
The Correlation Matrix of the Brazilian Central Bank's Standard Model for Interest Rate Market Risk
Central Bank of Brazil is implementing a Value At Risk (V.A.R.) methodology to establish minimum capital requirements for financial institutions to bear market risk derived from interest rate fluctuations. This article shows that the construction of the correlation matrix of the Brazilian Central Bank's Standard Model for Interest Rate is coherent, in the sense it is positive defined.
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