14,147 research outputs found
Model waveform accuracy standards for gravitational wave data analysis
Model waveforms are used in gravitational wave data analysis to detect and then to measure the properties of a source by matching the model waveforms to the signal from a detector. This paper derives accuracy standards for model waveforms which are sufficient to ensure that these data analysis applications are capable of extracting the full scientific content of the data, but without demanding excessive accuracy that would place undue burdens on the model waveform simulation community. These accuracy standards are intended primarily for broadband model waveforms produced by numerical simulations, but the standards are quite general and apply equally to such waveforms produced by analytical or hybrid analytical-numerical methods
Improved Time-Domain Accuracy Standards for Model Gravitational Waveforms
Model gravitational waveforms must be accurate enough to be useful for
detection of signals and measurement of their parameters, so appropriate
accuracy standards are needed. Yet these standards should not be unnecessarily
restrictive, making them impractical for the numerical and analytical modelers
to meet. The work of Lindblom, Owen, and Brown [Phys. Rev. D 78, 124020 (2008)]
is extended by deriving new waveform accuracy standards which are significantly
less restrictive while still ensuring the quality needed for gravitational-wave
data analysis. These new standards are formulated as bounds on certain norms of
the time-domain waveform errors, which makes it possible to enforce them in
situations where frequency-domain errors may be difficult or impossible to
estimate reliably. These standards are less restrictive by about a factor of 20
than the previously published time-domain standards for detection, and up to a
factor of 60 for measurement. These new standards should therefore be much
easier to use effectively.Comment: 10 pages, 5 figure
Comment on ``Scaling Laws for a System with Long-Range Interactions within Tsallis Statistics''
In their recent Letter [Phys. Rev. Lett. 83, 4233 (1999)], Salazar and Toral
(ST) study numerically a finite Ising chain with non-integrable interactions
decaying like 1/r^(d+sigma) where -d <= sigma <= 0 (like ST, we discuss general
dimensionality d). In particular, they explore a presumed connection between
non-integrable interactions and Tsallis's non-extensive statistics. We point
out that (i) non-integrable interactions provide no more motivation for Tsallis
statistics than do integrable interactions, i.e., Gibbs statistics remain
meaningful for the non-integrable case, and in fact provide a {\em complete and
exact treatment}; and (ii) there are undesirable features of the method ST use
to regulate the non-integrable interactions.Comment: Accepted for publication in Phys. Rev. Let
Gravitational radiation from the r-mode instability
The instability in the r-modes of rotating neutron stars can (in principle)
emit substantial amounts of gravitational radiation (GR) which might be
detectable by LIGO and similar detectors. Estimates are given here of the
detectability of this GR based the non-linear simulations of the r-mode
instability by Lindblom, Tohline and Vallisneri. The burst of GR produced by
the instability in the rapidly rotating 1.4 solar mass neutron star in this
simulation is fairly monochromatic with frequency near 960 Hz and duration
about 100 s. A simple analytical expression is derived here for the optimal S/N
for detecting the GR from this type of source. For an object located at a
distance of 20 Mpc we estimate the optimal S/N to be in the range 1.2 to about
12.0 depending on the LIGO II configuration.Comment: 8 pages, 4 figure
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