4,695 research outputs found
Evolution of massive fields around a black hole in Horava gravity
We study the evolution of massive scalar field in the spacetime geometry of
Kehagias-Sfetsos(KS) black hole in deformed Horava-Lifshitz(HL) gravity by
numerical analysis. We find that the signature of HL theory is encoded in the
quasinormal mode(QNM) phase of the evolution of field. The QNM phase in the
evolution process lasts for a longer time in HL theory. QNMs involved in the
evolution of massive field are calculated and find that they have a higher
oscillation frequency and a lower damping rate than the Schwarzschild spacetime
case. We also study the relaxation of field in the intermediate and asymptotic
range and verified that behaviors of field in these phases are independent of
the HL parameter and is identical to the Schwarzschild case.Comment: The article was fully rewritten, references added, accepted to GR
Evolution of electromagnetic and Dirac perturbations around a black hole in Horava gravity
The evolution of electromagnetic and Dirac perturbations in the spacetime
geometry of Kehagias-Sfetsos(KS) black hole in the deformed Horava-Lifshitz(HL)
gravity is investigated and the associated quasinormal modes are evaluated
using time domain integration and WKB methods. We find a considerable deviation
in the nature of field evolution in HL theory from that in the Schwarzschild
spacetime and QNMs region extends over a longer time in HL theory before the
power-law tail decay begins. The dependence of the field evolution on the HL
parameter are studied. In the time domain picture we find that the
length of QNM region increases with . But the late time decay of field
follows the same power-law tail behavior as in the case of Schwarzschild black
hole.Comment: The article was fully rewritten, references added, to appear in MPL
Parametrised strict deformation quantization of C*-bundles and Hilbert C*-modules
In this paper, we use the parametrised strict deformation quantization of
C*-bundles obtained in a previous paper, and give more examples and
applications of this theory. In particular, it is used here to classify
H_3-twisted noncommutative torus bundles over a locally compact space. This is
extended to the case of general torus bundles and their parametrised strict
deformation quantization. Rieffel's basic construction of an algebra
deformation can be mimicked to deform a monoidal category, which deforms not
only algebras but also modules. As a special case, we consider the parametrised
strict deformation quantization of Hilbert C*-modules over C*-bundles with
fibrewise torus action.Comment: 13 page
Evaluation of a multimode fiber optic low coherence interferometer for path length resolved Doppler measurements of diffuse light \ud
The performance of a graded index multimode fiber optic low coherence Mach-Zehnder interferometer with phase modulation is analyzed. Investigated aspects were its ability to measure path length distributions and to perform path length resolved Doppler measurements of multiple scattered photons in a turbid suspension of particles undergoing Brownian and translational motion. The path length resolution of this instrument is compared with a system using single mode fibers for illumination and detection. The optical path lengths are determined from the zero order moment of the phase modulation peak in the power spectrum. The weighted first moment, which is equal to the average Doppler shift, shows a linear response for different mean flow velocities within the physiological rang
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