5,760 research outputs found
Bound states of the Klein-Gordon equation for vector and scalar general Hulthen-type potentials in D-dimension
We solve the Klein-Gordon equation in any -dimension for the scalar and
vector general Hulth\'{e}n-type potentials with any by using an
approximation scheme for the centrifugal potential. Nikiforov-Uvarov method is
used in the calculations. We obtain the bound state energy eigenvalues and the
corresponding eigenfunctions of spin-zero particles in terms of Jacobi
polynomials. The eigenfunctions are physical and the energy eigenvalues are in
good agreement with those results obtained by other methods for D=1 and 3
dimensions. Our results are valid for value when and for any
value when and D=1 or 3. The % -wave () binding energies for
a particle of rest mass are calculated for the three lower-lying
states using pure vector and pure scalar potentials.Comment: 25 page
Polarizing primordial gravitational waves by parity violation
We study primordial gravitational waves (PGWs) in the Horava-Lifshitz (HL)
theory of quantum gravity, in which high-order spatial derivative operators,
including the ones violating parity, generically appear in order for the theory
to be power-counting renormalizable and ultraviolet (UV) complete. Because of
both parity violation and non-adiabatic evolution of the modes due to a
modified dispersion relationship, a large polarization of PGWs becomes
possible, and it could be well within the range of detection of the BB, TB and
EB power spectra of the forthcoming cosmic microwave background (CMB)
observations.Comment: revtex4, 3 figures. Phys. Rev. D87, 103512 (2013
Bound State Solutions of Klein-Gordon Equation with the Kratzer Potential
The relativistic problem of spinless particle subject to a Kratzer potential
is analyzed. Bound state solutions for the s-wave are found by separating the
Klein-Gordon equation in two parts, unlike the similar works in the literature,
which provides one to see explicitly the relativistic contributions, if any, to
the solution in the non-relativistic limit.Comment: 6 page
General covariant Horava-Lifshitz gravity without projectability condition and its applications to cosmology
We consider an extended theory of Horava-Lifshitz gravity with the detailed
balance condition softly breaking, but without the projectability condition.
With the former, the number of independent coupling constants is significantly
reduced. With the latter and by extending the original foliation-preserving
diffeomorphism symmetry to include a local U(1)
symmetry, the spin-0 gravitons are eliminated. Thus, all the problems related
to them disappear, including the instability, strong coupling, and different
speeds in the gravitational sector. When the theory couples to a scalar field,
we find that the scalar field is not only stable in both the ultraviolet (UV)
and infrared (IR), but also free of the strong coupling problem, because of the
presence of high-order spatial derivative terms of the scalar field.
Furthermore, applying the theory to cosmology, we find that due to the
additional U(1) symmetry, the Friedmann-Robertson-Walker (FRW) universe is
necessarily flat. We also investigate the scalar, vector, and tensor
perturbations of the flat FRW universe, and derive the general linearized field
equations for each kind of the perturbations.Comment: 19 pages, comments are welcome!!
A Modified Synchrotron Model for Knots in the M87 Jet
For explaining the broadband spectral shape of knots in the M87 jet from
radio through optical to X-ray, we propose a modified synchrotron model that
considers the integrated effect of particle injection from different
acceleration sources in the thin acceleration region. This results in two break
frequencies at two sides of which the spectral index of knots in the M87 jet
changes. We discuss the possible implications of these results for the physical
properties in the M87 jet. The observed flux of the knots in the M87 jet from
radio to X-ray can be satisfactorily explained by the model, and the predicted
spectra from ultraviolet to X-ray could be further tested by future
observations. The model implies that the knots D, E, F, A, B, and C1 are
unlikely to be the candidate for the TeV emission recently detected in M87.Comment: 12 pages, 1 figure, 2 tables, Accepted for publication in ApJ Letter
Alternative scheme to generate a supersinglet state of three-level atoms
In this paper we propose an alternative scheme to generate a supersinglet
state of three three-level atoms via a single-mode of a cavity QED based on the
two-photon transitions described by the 'full microscopical Hamiltonian
approach'. In it, three three-level atoms prepared in suitable initial states
are sequentially sent through the cavity originally prepared in its vacuum
state. After an appropriate choice of the atom-cavity interaction times plus a
field detection the state that describes the whole atom-field system is
projected in the desired supersinglet state. The fidelity and success
probability of the state as well as the practical feasibility of the scheme are
discussed.Comment: 10 pages, 3 figures, 4 table
Interior estimates of derivatives and a Liouville type theorem for Parabolic -Hessian equations
In this paper, we establish the gradient and Pogorelov estimates for
-convex-monotone solutions to parabolic -Hessian equations of the form
. We also apply such estimates to
obtain a Liouville type result, which states that any -convex-monotone and
solution to in
must be a linear function of plus a
quadratic polynomial of , under some growth assumptions on .Comment: 14 page
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