17 research outputs found
Entanglement via Barut-Girardello coherent state for quantum algebra: bipartite composite system
Using noncocommutative coproduct properties of the quantum algebras, we
introduce and obtain, in a bipartite composite system, the Barut-Girardello
coherent state for the q-deformed algebra. The quantum coproduct
structure ensures this normalizable coherent state to be entangled. The
entanglement disappears in the classical limit, giving rise to a
factorizable state.Comment: 12 page
Applications of the Quon Algebra: 3-D Harmonic Oscillator and the Rotor Model
In this work we present a method to build in a systematic way a many-body
quon basis state. In particular, we show a closed expression for a given number
N of quons, restricted to the permutational symmetric subspace, which belongs
to the whole quonic space. The method is applied to two simple problems: the
three-dimensional harmonic oscillator and the rotor model and compared to
previous quantum algebra results. The differences obtained and possible future
applications are also discussed.Comment: 13 pages, 2 figure
Noncommutative Quantum Mechanics and rotating frames
We study the effect of noncommutativity of space on the physics of a quantum
interferometer located in a rotating disk in a gauge field background. To this
end, we develop a path-integral approach which allows defining an effective
action from which relevant physical quantities can be computed as in the usual
commutative case. For the specific case of a constant magnetic field, we are
able to compute, exactly, the noncommutative Lagrangian and the associated
shift on the interference pattern for any value of .Comment: 17 pages, presentation improved, references added. To appear in
Physical Review
Quons as su(2) Irreducible Tensor Operators
We prove that, for the quon algebra, which interpolates between the Bose and
Fermi statistics and depends on a free parameter q,it is possible to build an
su(2) irreducible representation. One of the consequences of this fact is that
the quons couple via the same angular momentum coupling rules obeyed by
ordinary bosons and fermions.Comment: 8 pages,Late
Quons Restricted to the Antisymmetric Subspace: Formalism and Applications
In this work we develop a formalism to treat quons restricted to the
antisymmetric part of their many-body space. A model in which a system of
identical quons interact through a pairing force is then solved within this
restriction and the differences between our solution and the usual fermionic
model solution are then presented and discussed in detail. Possible connections
to physical systems are also considered.Comment: 12 pages, 3 figure
Nonlocal Equation of State in Anisotropic Static Fluid Spheres in General Relativity
We show that it is possible to obtain credible static anisotropic spherically
symmetric matter configurations starting from known density profiles and
satisfying a nonlocal equation of state. These particular types of equation of
state describe, at a given point, the components of the corresponding
energy-momentum tensor not only as a function at that point, but as a
functional throughout the enclosed configuration. To establish the physical
plausibility of the proposed family of solutions satisfying nonlocal equation
of state, we study the constraints imposed by the junction and energy
conditions on these bounded matter distributions.
We also show that it is possible to obtain physically plausible static
anisotropic spherically symmetric matter configurations, having nonlocal
equations of state\textit{,}concerning the particular cases where the radial
pressure vanishes and, other where the tangential pressures vanishes. The later
very particular type of relativistic sphere with vanishing tangential stresses
is inspired by some of the models proposed to describe extremely magnetized
neutron stars (magnetars) during the transverse quantum collapse.Comment: 21 pages, 1 figure, minor changes in the text, references added, two
new solutions studie
Localization of gravity in brane world with arbitrary extra dimensions
We study the induced 4-dimensional linearized Einstein field equations in an
m-dimensional bulk space by means of a confining potential. It is shown that in
this approach the mass of graviton is quantized. The cosmological constant
problem is also addressed within the context of this approach. We show that the
difference between the values of the cosmological constant in particle physics
and cosmology stems from our measurements in two different scales, small and
large.Comment: 8 pages. arXiv admin note: substantial text overlap with
arXiv:gr-qc/0408004, arXiv:gr-qc/0607067, arXiv:0704.1035, arXiv:0707.3558,
arXiv:0710.266
The Effective Lagrangian in the Randall-Sundrum Model and Electroweak Physics
We consider the two-brane Randall-Sundrum (RS) model with bulk gauge fields.
We carefully match the bulk theory to a 4D low-energy effective Lagrangian. In
addition to the four-fermion operators induced by KK exchange we find that
large negative S and T parameters are induced in the effective theory. This is
a tree-level effect and is a consequence of the shapes of the W and Z wave
functions in the bulk. Such effects are generic in extra dimensional theories
where the standard model (SM) gauge bosons have non-uniform wave functions
along the extra dimension. The corrections to precision electroweak observables
in the RS model are mostly dominated by S. We fit the parameters of the RS
model to the experimental data and find somewhat stronger bounds than
previously obtained; however, the standard model bound on the Higgs mass from
precision measurements can only be slightly relaxed in this theory.Comment: 16 pages, LaTeX, 1 figure included, uses JHEP.cls, extended
introduction, added reference
Heisenberg-type structures of one-dimensional quantum Hamiltonians
We construct a Heisenberg-like algebra for the one dimensional infinite
square-well potential in quantum mechanics. The ladder operators are realized
in terms of physical operators of the system as in the harmonic oscillator
algebra. These physical operators are obtained with the help of variables used
in a recently developed non commutative differential calculus. This
\textquotedblleft square-well algebra\textquotedblright is an example of an
algebra in a large class of generalized Heisenberg algebras recently
constructed. This class of algebras also contains -oscillators as a
particular case. We also discuss the physical content of this large class of
algebras.Comment: 11 pages. The title and abstract were modified and minor corrections
were made in the paper's core. Final version to appear in Phys. Rev.
Hybrid Stars in a Strong Magnetic Field
We study the effects of high magnetic fields on the particle population and
equation of state of hybrid stars using an extended hadronic and quark SU(3)
non-linear realization of the sigma model. In this model the degrees of freedom
change naturally from hadrons to quarks as the density and/or temperature
increases. The effects of high magnetic fields and anomalous magnetic moment
are visible in the macroscopic properties of the star, such as mass, adiabatic
index, moment of inertia, and cooling curves. Moreover, at the same time that
the magnetic fields become high enough to modify those properties, they make
the star anisotropic.Comment: Revised version with updated reference