5 research outputs found
Measurements of the optical mirror coating properties
The results of measurement of optical mirror coating are presented. These
results indicate that Standard Quantum Limit of sensitivity can be reached in
the second stage of LIGO project if it is limited by thermoelastic noise in the
coating only.Comment: 5 page
Quintessence and Gravitational Waves
We investigate some aspects of quintessence models with a non-minimally
coupled scalar field and in particular we show that it can behave as a
component of matter with . We study the
properties of gravitational waves in this class of models and discuss their
energy spectrum and the cosmic microwave background anisotropies they induce.
We also show that gravitational waves are damped by the anisotropic stress of
the radiation and that their energy spectrum may help to distinguish between
inverse power law potential and supergravity motivated potential. We finish by
a discussion on the constraints arising from their density parameter
\Omega_\GW.Comment: 21 pages, 18 figures, fianl version, accepted for publication in PR
Modeling gravitational radiation from coalescing binary black holes
With the goal of bringing theory, particularly numerical relativity, to bear
on an astrophysical problem of critical interest to gravitational wave
observers we introduce a model for coalescence radiation from binary black hole
systems. We build our model using the "Lazarus approach", a technique that
bridges far and close limit approaches with full numerical relativity to solve
Einstein equations applied in the truly nonlinear dynamical regime. We
specifically study the post-orbital radiation from a system of equal-mass
non-spinning black holes, deriving waveforms which indicate strongly circularly
polarized radiation of roughly 3% of the system's total energy and 12% of its
total angular momentum in just a few cycles. Supporting this result we first
establish the reliability of the late-time part of our model, including the
numerical relativity and close-limit components, with a thorough study of
waveforms from a sequence of black hole configurations varying from previously
treated head-on collisions to representative target for ``ISCO'' data
corresponding to the end of the inspiral period. We then complete our model
with a simple treatment for the early part of the spacetime based on a standard
family of initial data for binary black holes in circular orbit. A detailed
analysis shows strong robustness in the results as the initial separation of
the black holes is increased from 5.0 to 7.8M supporting our waveforms as a
suitable basic description of the astrophysical radiation from this system.
Finally, a simple fitting of the plunge waveforms is introduced as a first
attempt to facilitate the task of analyzing data from gravitational wave
detectors.Comment: 23 pages, 36 figures, RevTeX