10,211 research outputs found
Accurate time-domain gravitational waveforms for extreme-mass-ratio binaries
The accuracy of time-domain solutions of the inhomogeneous Teukolsky equation
is improved significantly. Comparing energy fluxes in gravitational waves with
highly accurate frequency-domain results for circular equatorial orbits in
Schwarzschild and Kerr, we find agreement to within 1% or better, which we
believe can be even further improved. We apply our method to orbits for which
frequency-domain calculations have a relative disadvantage, specifically
high-eccentricity (elliptical and parabolic) "zoom-whirl" orbits, and find the
energy fluxes, waveforms, and characteristic strain in gravitational waves.Comment: 6 pages, 9 figures, 2 tables; Changes: some errors corrected.
Comparison with Frequency-domain now done in stronger fiel
Galilei covariance and (4,1) de Sitter space
A vector space G is introduced such that the Galilei transformations are
considered linear mappings in this manifold. The covariant structure of the
Galilei Group (Y. Takahashi, Fortschr. Phys. 36 (1988) 63; 36 (1988) 83) is
derived and the tensor analysis is developed. It is shown that the Euclidean
space is embedded the (4,1) de Sitter space through in G. This is an
interesting and useful aspect, in particular, for the analysis carried out for
the Lie algebra of the generators of linear transformations in G.Comment: Late
Analysis of direct CP violation in decays
We investigate the possibility of observing the direct CP violation in the
decay modes and within the Standard Model.
Including the contributions arising from the tree, annihilation, QCD as well as
electroweak penguins with both time- and space-like components, we find that
the direct CP asymmetry in is very small % but
in decay it can be as large as 4%. Approximately
charged mesons are required to experimentally observe the CP asymmetry
parameter for the later case. Since this is easily accessible with the
currently running B factories, the decay mode may be pursued
to look for CP violation.Comment: Latex, 14 page
Black hole binary inspiral and trajectory dominance
Gravitational waves emitted during the inspiral, plunge and merger of a black
hole binary carry linear momentum. This results in an astrophysically important
recoil to the final merged black hole, a ``kick'' that can eject it from the
nucleus of a galaxy. In a previous paper we showed that the puzzling partial
cancellation of an early kick by a late antikick, and the dependence of the
cancellation on black hole spin, can be understood from the phenomenology of
the linear momentum waveforms. Here we connect that phenomenology to its
underlying cause, the spin-dependence of the inspiral trajectories. This
insight suggests that the details of plunge can be understood more broadly with
a focus on inspiral trajectories.Comment: 15 pages, 12 figure
Systematics of black hole binary inspiral kicks and the slowness approximation
During the inspiral and merger of black holes, the interaction of
gravitational wave multipoles carries linear momentum away, thereby providing
an astrophysically important recoil, or "kick" to the system and to the final
black hole remnant. It has been found that linear momentum during the last
stage (quasinormal ringing) of the collapse tends to provide an "antikick" that
in some cases cancels almost all the kick from the earlier (quasicircular
inspiral) emission. We show here that this cancellation is not due to
peculiarities of gravitational waves, black holes, or interacting multipoles,
but simply to the fact that the rotating flux of momentum changes its intensity
slowly. We show furthermore that an understanding of the systematics of the
emission allows good estimates of the net kick for numerical simulations
started at fairly late times, and is useful for understanding qualitatively
what kinds of systems provide large and small net kicks.Comment: 15 pages, 6 figures, 2 table
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