10,542 research outputs found
Lagrangian approach to local symmetries and self-dual model in gauge invariant formulation
Taking the St\"uckelberg Lagrangian associated with the abelian self-dual
model of P.K. Townsend et al as a starting point, we embed this mixed first-
and second-class system into a pure first-class system by following
systematically the generalized Hamiltonian approach of Batalin, Fradkin and
Tyutin. The resulting Lagrangian possesses an extended gauge invariance and
provides a non-trivial example for a general Lagrangian approach to unravelling
the full set of local symmetries of a Lagrangian.Comment: LaTeX, 15 page
Entropy of the Randall-Sundrum brane world with the generalized uncertainty principle
By introducing the generalized uncertainty principle, we calculate the
entropy of the bulk scalar field on the Randall-Sundrum brane background
without any cutoff. We obtain the entropy of the massive scalar field
proportional to the horizon area. Here, we observe that the mass contribution
to the entropy exists in contrast to all previous results, which is independent
of the mass of the scalar field, of the usual black hole cases with the
generalized uncertainty principle.Comment: 12 pages. The improved version published in Phys. Rev.
Quantization of spontaneously broken gauge theory based on the BFT-BFV Formalism
We quantize the spontaneously broken abelian U(1) Higgs model by using the
improved BFT and BFV formalisms. We have constructed the BFT physical fields,
and obtain the first class observables including the Hamiltonian in terms of
these fields. We have also explicitly shown that there are exact form
invariances between the second class and first class quantities. Then,
according to the BFV formalism, we have derived the corresponding Lagrangian
having U(1) gauge symmetry. We also discuss at the classical level how one
easily gets the first class Lagrangian from the symmetry-broken second class
Lagrangian.Comment: 16 pages, latex, final version published in Mod. Phys. Lett.
Thermodynamic duality between RN black hole and 2D dilaton gravity
All thermodynamic quantities of the Reissner-Nordstr\"om (RN) black hole can
be obtained from the dilaton and its potential of two dimensional (2D) dilaton
gravity. The dual relations of four thermodynamic laws are also established.
Furthermore, the near-horizon thermodynamics of the extremal RN black hole is
completely described by the Jackiw-Teitelboim theory which is obtained by
perturbing around the AdS-horizon.Comment: 10 pages, 3 figures, version accepted by MPL
Symplectic embedding and Hamilton-Jacobi analysis of Proca model
Following the symplectic approach we show how to embed the Abelian Proca
model into a first-class system by extending the configuration space to include
an additional pair of scalar fields, and compare it with the improved Dirac
scheme. We obtain in this way the desired Wess-Zumino and gauge fixing terms of
BRST invariant Lagrangian. Furthermore, the integrability properties of the
second-class system described by the Abelian Proca model are investigated using
the Hamilton-Jacobi formalism, where we construct the closed Lie algebra by
introducing operators associated with the generalized Poisson brackets.Comment: 24 page
Finite-Difference Time Domain Method for Nonorthogonal Unit-Cell Two-Dimensional Photonic Crystals
A finite-difference time-domain (FDTD) method based on a regular Cartesian Yee’s lattice is developed for calculating the dispersion band diagram of a 2-D photonic crystal. Unlike methods that require auxiliary difference equations or nonorthogonal grid schemes, our method uses the standard centraldifference equations and can be easily implemented in a parallel computing environment. The application of the periodic boundary condition on an angled boundary involves a split-field formulation of Maxwell’s equations. We show that the method can be applied for photonic crystals of both orthogonal and nonorthogonal unit cells. Complete and accurate bandgap information is obtained by using this FDTD approach. Numerical results for 2-D TE/TM modes in triangular lattice photonic crystals are in excellent agreement with the results from 2-D plane wave expansion method. For a triangular lattice photonic crystal slab, the dispersion relation is calculated by a 3-D FDTD method similarly formulated. The result agrees well with the 3-D finite-element method solution. The calculations also show that the 2-D simulation using an effective index approximation can result in considerable error for higher bands
Hamiltonian Embedding of SU(2) Higgs Model in the Unitary Gauge
Following systematically the generalized Hamiltonian approach of Batalin,
Fradkin and Tyutin (BFT), we embed the second-class non-abelian SU(2) Higgs
model in the unitary gauge into a gauge invariant theory. The strongly
involutive Hamiltonian and constraints are obtained as an infinite power series
in the auxiliary fields. Furthermore, comparing these results with those
obtained from the gauged second class Lagrangian, we arrive at a simple
interpretation for the first class Hamiltonian, constraints and observables.Comment: 13 pages, Latex, no figure
Preheating and Affleck-Dine leptogenesis after thermal inflation
Previously, we proposed a model of low energy Affleck-Dine leptogenesis in
the context of thermal inflation. The lepton asymmetry is generated at the end
of thermal inflation, which occurs at a relatively low energy scale with the
Hubble parameter somewhere in the range 1 \keV \lesssim H \lesssim 1 \MeV.
Thus Hubble damping will be ineffective in bringing the Affleck-Dine field into
the lepton conserving region near the origin, leaving the possibility that the
lepton number could be washed out. Previously, we suggested that preheating
could damp the amplitude of the Affleck-Dine field allowing conservation of the
lepton number. In this paper, we demonstrate numerically that preheating does
efficiently damp the amplitude of the Affleck-Dine field and that the lepton
number is conserved as the result. In addition to demonstrating a crucial
aspect of our model, it also opens the more general possibility of low energy
Affleck-Dine baryogenesis.Comment: 38 pages, 17 figure
Symplectic quantization of self-dual master Lagrangian
We consider the master Lagrangian of Deser and Jackiw, interpolating between
the self-dual and the Maxwell-Chern-Simons Lagrangian, and quantize it
following the symplectic approach, as well as the traditional Dirac scheme. We
demonstrate the equivalence of these procedures in the subspace of the
second-class constraints. We then proceed to embed this mixed first- and
second-class system into an extended first-class system within the framework of
both approaches, and construct the corresponding generator for this extended
gauge symmetry in both formulations.Comment: 27 page
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