11,013 research outputs found
Quasinormal modes and late-time tails in the background of Schwarzschild black hole pierced by a cosmic string: scalar, electromagnetic and gravitational perturbations
We have studied the quasinormal modes and the late-time tail behaviors of
scalar, electromagnetic and gravitational perturbations in the Schwarzschild
black hole pierced by a cosmic string. Although the metric is locally identical
to that of the Schwarzschild black hole so that the presence of the string will
not imprint in the motion of test particles, we found that quasinormal modes
and the late-time tails can reflect physical signatures of the cosmic string.
Compared with the scalar and electromagnetic fields, the gravitational
perturbation decays slower, which could be more interesting to disclose the
string effect in this background.Comment: 17 pages; 7 figure
Matched-filtering and parameter estimation of ringdown waveforms
Using recent results from numerical relativity simulations of non-spinning
binary black hole mergers we revisit the problem of detecting ringdown
waveforms and of estimating the source parameters, considering both LISA and
Earth-based interferometers. We find that Advanced LIGO and EGO could detect
intermediate-mass black holes of mass up to about 1000 solar masses out to a
luminosity distance of a few Gpc. For typical multipolar energy distributions,
we show that the single-mode ringdown templates presently used for ringdown
searches in the LIGO data stream can produce a significant event loss (> 10%
for all detectors in a large interval of black hole masses) and very large
parameter estimation errors on the black hole's mass and spin. We estimate that
more than 10^6 templates would be needed for a single-stage multi-mode search.
Therefore, we recommend a "two stage" search to save on computational costs:
single-mode templates can be used for detection, but multi-mode templates or
Prony methods should be used to estimate parameters once a detection has been
made. We update estimates of the critical signal-to-noise ratio required to
test the hypothesis that two or more modes are present in the signal and to
resolve their frequencies, showing that second-generation Earth-based detectors
and LISA have the potential to perform no-hair tests.Comment: 19 pages, 9 figures, matches version in press in PR
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