9,203 research outputs found
Surface Waves and Forced Oscillations in QHE Planar Samples
Dispersion relations and polarizations for surface waves in infinite planar
samples in the QHE regime are explicitly determined in the small wavevector
limit in which the dielectric tensor can be considered as local. The wavelength
and frequency regions of applicability of the results extends to the infrared
region for typical experimental conditions. Then, standard samples with
millimetric sizes seem to be able to support such excitations. Forced
oscillations are also determined which should be generated in the 2DEG by
external electromagnetic sources. They show an almost frequency independent
wavevelength which decreases with the magnetic field. A qualitative model based
in these solutions is also presented to describe a recently found new class of
resonances appearing near the edge of a 2DEG in the QHE regime.Comment: latex file, 18 pages, 3 figures, spelling correcte
Coupled scalar fields Oscillons and Breathers in some Lorentz Violating Scenarios
In this work we discuss the impact of the breaking of the Lorentz symmetry on
the usual oscillons, the so-called flat-top oscillons, and the breathers. Our
analysis is performed by using a Lorentz violation scenario rigorously derived
in the literature. We show that the Lorentz violation is responsible for the
origin of a kind of deformation of the configuration, where the field
configuration becomes oscillatory in a localized region near its maximum value.
Furthermore, we show that the Lorentz breaking symmetry produces a displacement
of the oscillon along the spatial direction, the same feature is present in the
case of breathers. We also show that the effect of a Lorentz violation in the
flat-top oscillon solution is responsible by the shrinking of the flat-top.
Furthermore, we find analytically the outgoing radiation, this result indicates
that the amplitude of the outgoing radiation is controlled by the Lorentz
breaking parameter, in such away that this oscillon becomes more unstable than
its symmetric counterpart, however, it still has a long living nature
On the study of oscillons in scalar field theories: A new approach
In this work we study configurations in one-dimensional scalar field theory,
which are time-dependent, localized in space and extremely long-lived called
oscillons. It is investigated how the action of changing the minimum value of
the field configuration representing the oscillon affects its behavior. We find
that one of the consequences of this procedure, is the appearance of a pair of
oscillon-like structures presenting different amplitudes and frequencies of
oscillation. We also compare our analytical results to numerical ones, showing
excellent agreement
The importance of scalar fields as extradimensional metric components in Kaluza-Klein models
Extradimensional models are achieving their highest popularity nowadays,
among other reasons, because they can plausible explain some standard cosmology
issues, such as the cosmological constant and hierarchy problems. In
extradimensional models, we can infer that the four-dimensional matter rises as
a geometric manifestation of the extra coordinate. In this way, although we
still cannot see the extra dimension, we can relate it to physical quantities
that are able to exert such a mechanism of matter induction in the observable
universe. In this work we propose that scalar fields are those physical
quantities. The models here presented are purely geometrical in the sense that
no matter lagrangian is assumed and even the scalar fields are contained in the
extradimensional metric. The results are capable of describing different
observable cosmic features and yield an alternative to ultimately understand
the extra dimension and the mechanism in which it is responsible for the
creation of matter in the observable universe
Configurational entropy in brane models
In this work we investigate generalized theories of gravity in the so-called
configurational entropy (CE) context. We show, by means of this
information-theoretical measure, that a stricter bound on the parameter of
brane models arises from the CE. We find that these bounds are
characterized by a valley region in the CE profile, where the entropy is
minimal. We argue that the CE measure can open a new role and an important
additional approach to select parameters in modified theories of gravitation
Information-Entropic Measure of Energy-Degenerate Kinks in Two-Field Models
We investigate the existence and properties of kink-like solitons in a class
of models with two interacting scalar fields. In particular, we focus on models
that display both double and single-kink solutions, treatable analytically
using the Bogomol'nyi--Prasad--Sommerfield bound (BPS). Such models are of
interest in applications that include Skyrmions and various
superstring-motivated theories. Exploring a region of parameter space where the
energy for very different spatially-bound configurations is degenerate, we show
that a newly-proposed momentum-space entropic measure called Configurational
Entropy (CE) can distinguish between such energy-degenerate spatial profiles.
This information-theoretic measure of spatial complexity provides a
complementary perspective to situations where strictly energy-based arguments
are inconclusive
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