13,727 research outputs found
Dual Actions for Born-Infeld and Dp-Brane Theories
Dual actions with respect to U(1) gauge fields for Born-Infeld and -brane
theories are reexamined. Taking into account an additional condition, i.e. a
corollary to the field equation of the auxiliary metric, one obtains an
alternative dual action that does not involve the infinite power series in the
auxiliary metric given by ref. \cite{s14}, but just picks out the first term
from the series formally. New effective interactions of the theories are
revealed. That is, the new dual action gives rise to an effective interaction
in terms of one interaction term rather than infinite terms of different
(higher) orders of interactions physically. However, the price paid for
eliminating the infinite power series is that the new action is not quadratic
but highly nonlinear in the Hodge dual of a -form field strength. This
non-linearity is inevitable to the requirement the two dual actions are
equivalent.Comment: v1: 11 pages, no figures; v2: explanation of effective interactions
added; v3: concision made; v4: minor modification mad
Critical points of Wang-Yau quasi-local energy
In this paper, we prove the following theorem regarding the Wang-Yau
quasi-local energy of a spacelike two-surface in a spacetime: Let be a
boundary component of some compact, time-symmetric, spacelike hypersurface
in a time-oriented spacetime satisfying the dominant energy
condition. Suppose the induced metric on has positive Gaussian
curvature and all boundary components of have positive mean curvature.
Suppose where is the mean curvature of in and
is the mean curvature of when isometrically embedded in .
If is not isometric to a domain in , then 1. the Brown-York mass
of in is a strict local minimum of the Wang-Yau quasi-local
energy of , 2. on a small perturbation of in
, there exists a critical point of the Wang-Yau quasi-local energy of
.Comment: substantially revised, main theorem replaced, Section 3 adde
Duality Symmetry in Momentum Frame
Siegel's action is generalized to the D=2(p+1) (p even) dimensional
space-time. The investigation of self-duality of chiral p-forms is extended to
the momentum frame, using Siegel's action of chiral bosons in two space-time
dimensions and its generalization in higher dimensions as examples. The whole
procedure of investigation is realized in the momentum space which relates to
the configuration space through the Fourier transformation of fields. These
actions correspond to non-local Lagrangians in the momentum frame. The
self-duality of them with respect to dualization of chiral fields is uncovered.
The relationship between two self-dual tensors in momentum space, whose similar
form appears in configuration space, plays an important role in the
calculation, that is, its application realizes solving algebraically an
integral equation.Comment: 11 pages, no figures, to appear in Phys. Rev.
Orbital Characters Determined from Fermi Surface Intensity Patterns using Angle-Resolved Photoemission Spectroscopy
In order to determine the orbital characters on the various Fermi surface
pockets of the Fe-based superconductors BaKFeAs and
FeSeTe, we introduce a method to calculate photoemission
matrix elements. We compare our simulations to experimental data obtained with
various experimental configurations of beam orientation and light polarization.
We show that the photoemission intensity patterns revealed from angle-resolved
photoemission spectroscopy measurements of Fermi surface mappings and
energy-momentum plots along high-symmetry lines exhibit asymmetries carrying
precious information on the nature of the states probed, information that is
destroyed after the data symmetrization process often performed in the analysis
of angle-resolved photoemission spectroscopy data. Our simulations are
consistent with Fermi surfaces originating mainly from the ,
and orbitals in these materials.Comment: 16 pages, 9 figures. Figures modified, typos corrected, appendix
adde
Massive charged particle's tunneling from spherical charged black hole
We generalize the Parikh-Wilczek scheme to the tunneling of a massive charged
particle from a general spherical charged black hole. We obtain that the
tunneling probability depends on the energy, the mass and the charge of the
particle. In particular, the modified Hawking temperature is related to the
charge. Only at the leading order approximation can the standard Hawking
temperature be reproduced. We take the Reissner-Nordstr\"{o}m black hole as an
example to clarify our points of view, and find that the accumulation of
Hawking radiation makes it approach an extreme black hole.Comment: 10 pages, no figures; v2: a minor typo corrected; v3: 11 pages,
clarification and reference added, final version to be published in EPL; v4:
minor modifications to match the published versio
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