42,538 research outputs found
Asymptotic Quasinormal Frequencies of Different Spin Fields in Spherically Symmetric Black Holes
We consider the asymptotic quasinormal frequencies of various spin fields in
Schwarzschild and Reissner-Nordstr\"om black holes. In the Schwarzschild case,
the real part of the asymptotic frequency is ln3 for the spin 0 and the spin 2
fields, while for the spin 1/2, the spin 1, and the spin 3/2 fields it is zero.
For the non-extreme charged black holes, the spin 3/2 Rarita-Schwinger field
has the same asymptotic frequency as that of the integral spin fields. However,
the asymptotic frequency of the Dirac field is different, and its real part is
zero. For the extremal case, which is relevant to the supersymmetric
consideration, all the spin fields have the same asymptotic frequency, the real
part of which is zero. For the imaginary parts of the asymptotic frequencies,
it is interesting to see that it has a universal spacing of for all the
spin fields in the single-horizon cases of the Schwarzschild and the extreme
Reissner-Nordstr\"om black holes. The implications of these results to the
universality of the asymptotic quasinormal frequencies are discussed.Comment: Revtex, 17 pages, 3 eps figures; one table, some remarks and
references added to section I
Monopoles and Knots in Skyrme Theory
We show that the Skyrme theory actually is a theory of monopoles which allows
a new type of solitons, the topological knots made of monopole-anti-monopole
pair,which is different from the well-known skyrmions. Furthermore, we derive a
generalized Skyrme action from the Yang-Mills action of QCD, which we propose
to be an effective action of QCD in the infra-red limit. We discuss the
physical implications of our results.Comment: 4 pages. Phys. Rev. Lett. in pres
Dilaton as a Dark Matter Candidate and its Detection
Assuming that the dilaton is the dark matter of the universe, we propose an
experiment to detect the relic dilaton using the electromagnetic resonant
cavity, based on the dilaton-photon conversion in strong electromagnetic
background. We calculate the density of the relic dilaton, and estimate the
dilaton mass for which the dilaton becomes the dark matter of the universe.
With this we calculate the dilaton detection power in the resonant cavity, and
compare it with the axion detection power in similar resonant cavity
experiment.Comment: 23 pages, 2 figure
Geometrization of the Gauge Connection within a Kaluza-Klein Theory
Within the framework of a Kaluza-Klein theory, we provide the geometrization
of a generic (Abelian and non-Abelian) gauge coupling, which comes out by
choosing a suitable matter fields dependence on the extra-coordinates.
We start by the extension of the Nother theorem to a multidimensional
spacetime being the direct sum of a 4-dimensional Minkowski space and of a
compact homogeneous manifold (whose isometries reflect the gauge symmetry); we
show, how on such a ``vacuum'' configuration, the extra-dimensional components
of the field momentum correspond to the gauge charges. Then we analyze the
structure of a Dirac algebra as referred to a spacetime with the Kaluza-Klein
restrictions and, by splitting the corresponding free-field Lagrangian, we show
how the gauge coupling terms outcome.Comment: 10 pages, no figure, to appear on Int. Journ. Theor. Phy
Lineal Trails of D2-D2bar Superstrings
We study the superstrings suspended between a D2- and an anti-D2-brane. We
quantize the string in the presence of some general configuration of gauge
fields over the (anti-)D-brane world volumes. The interstring can move only in
a specific direction that is normal to the difference of the electric fields of
each (anti-)D-branes. Especially when the electric fields are the same, the
interstring cannot move. We obtain the condition for the tachyons to disappear
from the spectrum.Comment: 15 pages with 4 figures, referenced added, Sec. 5 on the spectrum
made cleare
Gauge Independent Trace Anomaly for Gravitons
We show that the trace anomaly for gravitons calculated using the usual
effective action formalism depends on the choice of gauge when the background
spacetime is not a solution of the classical equation of motion, that is, when
off-shell. We then use the gauge independent Vilkovisky-DeWitt effective action
to restore gauge independence to the off-shell case. Additionally we explicitly
evaluate trace anomalies for some N-sphere background spacetimes.Comment: 19 pages, additional references and title chang
On the implications of a dilaton in gauge theory
Some recent work on the implications of a dilaton in 4d gauge theories are
revisited. In part I of this paper we see how an effective dilaton coupling to
gauge kinetic term provides a simple attractive mechanism to generate
confinement. In particular, we put emphasis on the derivation of confining
analytical solutions and look into the problem how dilaton degrees of freedom
modify Coulom potential and when a confining phase occurs. In part II, we solve
the semi-relativistic wave equation, for Dick interquark potential using the
Shifted l-expansion technique (SLET) in the heavy quarkonium sector. The
results of this phenomenological analysis proves that these effective theories
can be relevant to model quark confinement and may shed some light on
confinement mechanism.Comment: 8 pages. Talk given at CTP Symposium on Supersymmetry at LHC:
Theoretical and Experimental Prospectives, Cairo, Egypt, 11-14 Mar 200
Dyon condensation in topological Mott insulators
We consider quantum phase transitions out of topological Mott insulators in
which the ground state of the fractionalized excitations (fermionic spinons) is
topologically non-trivial. The spinons in topological Mott insulators are
coupled to an emergent compact U(1) gauge field with a so-called "axion" term.
We study the confinement transitions from the topological Mott insulator to
broken symmetry phases, which may occur via the condensation of dyons. Dyons
carry both "electric" and "magnetic" charges, and arise naturally in this
system because the monopoles of the emergent U(1) gauge theory acquires gauge
charge due to the axion term. It is shown that the dyon condensate, in general,
induces simultaneous current and bond orders. To demonstrate this, we study the
confined phase of the topological Mott insulator on the cubic lattice. When the
magnetic transition is driven by dyon condensation, we identify the bond order
as valence bond solid order and the current order as scalar spin chirality
order. Hence, the confined phase of the topological Mott insulator is an exotic
phase where the scalar spin chirality and the valence bond order coexist and
appear via a single transition. We discuss implications of our results for
generic models of topological Mott insulators.Comment: 14 pages, accepted to the New Journal of Physic
Color Reflection Invariance and Monopole Condensation in QCD
We review the quantum instability of the Savvidy-Nielsen-Olesen (SNO) vacuum
of the one-loop effective action of SU(2) QCD, and point out a critical defect
in the calculation of the functional determinant of the gluon loop in the SNO
effective action. We prove that the gauge invariance, in particular the color
reflection invariance, exclude the unstable tachyonic modes from the gluon loop
integral. This guarantees the stability of the magnetic condensation in QCD.Comment: 28 pages, 3 figures, JHEP styl
- âŠ