Detecting Gravity Waves With Interferometers, In Space Options

[ljk4-1]

Paper (*cross-listing*): gr-qc/0511145
Date: Sun, 27 Nov 2005 19:24:09 GMT (116kb)

Title: Detecting a gravitational-wave background with next-generation space
interferometers

Authors: Hideaki Kudoh, Atsushi Taruya, Takashi Hiramatsu, Yoshiaki Himemoto

Comments: 19 pages, 6 figures
\\
Future missions of gravitational-wave astronomy will be operated by
space-based interferometers, covering very wide range of frequency band. Search
for stochastic gravitational-wave backgrounds (GWBs) is one of the main target
for such missions, and we here discuss the prospects for direct measurement of
isotropic and anisotropic components of (primordial) GWBs around the frequency
0.1-10 Hz. After extending the theoretical basis for correlation analysis, we
evaluate the sensitivity and the signal-to-noise ratio for the proposed future
missions of space interferometers, like Big-Bang Observer (BBO), Deci-Hertz
Interferometer Gravitational-wave Observer (DECIGO) and recently proposed
Fabry-Perot type DECIGO. The astrophysical foregrounds which are expected at
the low frequency may be a big obstacle and significantly reduce the
signal-to-noise ratio of GWBs. As a result, minimum detectable amplitude may
reach h^2 \Omega = 10^{-15} - 10^{-16}, as long as foreground point sources are
properly subtracted. Based on the correlation analysis, we also discuss
measurement of anisotropies of GWBs. As an example, sensitivity level required
for detecting the dipole moment of GWB induced by the proper motion of our
local system is closely examined.

\\ ( http://arXiv.org/abs/gr-qc/0511145 , 116kb)

[ljk4-1]

Paper (*cross-listing*): gr-qc/0110101

Date: Tue, 23 Oct 2001 23:45:30 GMT (39kb)
Date (revised v2): Thu, 25 Oct 2001 14:53:42 GMT (39kb)

Title: Gravitomagnetic Effects in the Propagation of Electromagnetic Waves in
Variable Gravitational Fields of Arbitrary-Moving and Spinning Bodies

Authors: Sergei Kopeikin and Bahram Mashhoon (Department of Physics and
Astronomy, University of Missouri-Columbia)

Categories: gr-qc

Comments: 36 pages, 1 figure, submitted to Phys. Rev. D
Journal-ref: Phys.Rev. D65 (2002) 064025
\\
Propagation of light in the gravitational field of self-gravitating spinning
bodies moving with arbitrary velocities is discussed. The gravitational field
is assumed to be "weak" everywhere. Equations of motion of a light ray are
solved in the first post-Minkowskian approximation that is linear with respect
to the universal gravitational constant $G$. We do not restrict ourselves with
the approximation of gravitational lens so that the solution of light geodesics
is applicable for arbitrary locations of source of light and observer. This
formalism is applied for studying corrections to the Shapiro time delay in
binary pulsars caused by the rotation of pulsar and its companion. We also
derive the correction to the light deflection angle caused by rotation of
gravitating bodies in the solar system (Sun, planets) or a gravitational lens.
The gravitational shift of frequency due to the combined translational and
rotational motions of light-ray-deflecting bodies is analyzed as well. We give
a general derivation of the formula describing the relativistic rotation of the
plane of polarization of electromagnetic waves (Skrotskii effect). This formula
is valid for arbitrary translational and rotational motion of gravitating
bodies and greatly extends the results of previous researchers. Finally, we
discuss the Skrotskii effect for gravitational waves emitted by localized
sources such as a binary system. The theoretical results of this paper can be
applied for studying various relativistic effects in microarcsecond space
astrometry and developing corresponding algorithms for data processing in space
astrometric missions such as FAME, SIM, and GAIA.

\\ ( http://arXiv.org/abs/gr-qc/0110101 , 39kb)

------------------------------------------------------------------------------
\\
Paper (*cross-listing*): gr-qc/0510077

Date: Sun, 16 Oct 2005 20:54:46 GMT (33kb)

Title: Gravitomagnetism and the Lorentz Invariance of Gravity in the
Gravitational Light-Ray Deflection Experiments

Authors: Sergei M. Kopeikin (University of Missouri-Columbia, USA) and Edward
B. Fomalont (National Radio Astronomy Observatory, USA)

Comments: 25 pages including text, 3 figures and 1 table
\\
Experimental verification of the existence of gravitomagnetic fields
generated by currents of matter is important for a complete understanding and
formulation of gravitational physics. Although the rotational (intrinsic)
gravitomagnetic field has been extensively studied and is now being measured by
the Gravity Probe B, the extrinsic gravitomagnetic field generated by the
translational current of matter is less well studied. The present paper
introduces a fundamental speed of gravity parameter and uses the parametrized
Einstein and light geodesics equations to show that the extrinsic
gravitomagnetic field generated by the translational current of matter can be
measured by observing the relativistic time delay caused by the moving object.
We prove that the extrinsic gravitomagnetic field is measured by the
relativistic effect of the aberration of the gravity force caused by the
Lorentz transformation of the metric tensor and the Levi-Civita connection. We
applied these concepts to the 2002 deflection experiment of a quasar by Jupiter
where the aberration of gravity from its orbital motion was measured with
accuracy 20%. We describe a 2005 experiment to measure the gravitational
deflection of radio waves from a quasar by the sun, as viewed in the geocentric
frame, to improve the measurement accuracy of the aberration of gravity - hence
the fundamental speed of gravity - to a few percent.

\\ ( http://arXiv.org/abs/gr-qc/0510077 , 33kb)

------------------------------------------------------------------------------
\\
Paper (*cross-listing*): gr-qc/0510084

Date: Tue, 18 Oct 2005 21:47:50 GMT (76kb)

Title: General Relativistic Theory of Light Propagation in the Field of
Radiative Gravitational Multipoles

Authors: Sergei Kopeikin and Pavel Korobkov (University of Missouri-Columbia,
USA)

Comments: 61 pages, 4 figures
\\
The extremely high precision of current observations demands a much better
theoretical treatment of relativistic effects in the propagation of
electromagnetic signals through variable gravitational fields of isolated
astronomical systems emitted gravitational waves. A consistent approach giving
a complete and exhaustive solution to this problem in the first
post-Minkowskian approximation of General Relativity is presented in this
paper.

\\ ( http://arXiv.org/abs/gr-qc/0510084 , 76kb)

[ljk4-1]

Paper (*cross-listing*): gr-qc/0601001

Date: Sat, 31 Dec 2005 17:20:27 GMT (530kb)

Title: Coupling of Radial and Axial non-Radial Oscillations of Compact Stars:
Gravitational Waves from first-order Differential Rotation

Authors: A. Passamonti, M. Bruni, L. Gualtieri, A. Nagar, C. F. Sopuerta

Comments: RevTeX 4. 23 pages, 13 figures
\\
We investigate the non-linear coupling between radial and non-radial
oscillations of static spherically symmetric neutron stars as a possible
mechanism for the generation of gravitational waves that may lead to observable
signatures. In this paper we concentrate on the axial sector of the non-radial
perturbations. By using a multi-parameter perturbative framework we introduce a
complete description of the non-linear coupling between radial and axial
non-radial oscillations; we study the gauge invariant character of the
associated perturbative variables and develop a computational scheme to evolve
the non-linear coupling perturbations in the time domain. We present results of
simulations corresponding to different physical situations and discuss the
dynamical behaviour of this non-linear coupling. Of particular interest is the
occurrence of signal amplifications in the form of resonance phenomena when a
frequency associated with the radial pulsations is close to a frequency
associated with one of the axial w-modes of the star. Finally, we mention
possible extensions of this work and improvements towards more astrophysically
motivated scenarios.

\\ ( http://arXiv.org/abs/gr-qc/0601001 , 530kb)

[ljk4-1]

General Relativity and Quantum Cosmology, abstract
gr-qc/0506015

From: Neil J. Cornish [view email]

Date (v1): Fri, 3 Jun 2005 16:46:52 GMT (46kb)
Date (revised v2): Fri, 17 Jun 2005 04:35:37 GMT (46kb)
Date (revised v3): Mon, 17 Oct 2005 19:04:42 GMT (54kb)

Beyond LISA: Exploring Future Gravitational Wave Missions

Authors: Jeff Crowder, Neil J. Cornish

Comments: 9 pages, 10 figures, published version

Journal-ref: Phys.Rev. D72 (2005) 083005

The Advanced Laser Interferometer Antenna (ALIA) and the Big Bang Observer (BBO) have been proposed as follow on missions to the Laser Interferometer Space Antenna (LISA). Here we study the capabilities of these observatories, and how they relate to the science goals of the missions. We find that the Advanced Laser Interferometer Antenna in Stereo (ALIAS), our proposed extension to the ALIA mission, will go considerably further toward meeting ALIA's main scientific goal of studying intermediate mass black holes. We also compare the capabilities of LISA to a related extension of the LISA mission, the Laser Interferometer Space Antenna in Stereo (LISAS). Additionally, we find that the initial deployment phase of the BBO would be sufficient to address the BBO's key scientific goal of detecting the Gravitational Wave Background, while still providing detailed information about foreground sources.

http://arxiv.org/abs/gr-qc/0506015

[ljk4-1]

Astrophysics, abstract
astro-ph/0602345

From: Guenter Sigl [view email]

Date: Wed, 15 Feb 2006 16:24:21 GMT (39kb)

Cosmological Gravitational Wave Background from Phase Transitions in Neutron Stars

Authors: Guenter Sigl (APC and GReCO, IAP, Paris)

Comments: 12 latex pages, 4 ps figures included

It has recently been suggested that collapse of neutron stars induced by a phase transition to quark matter can be a considerable source of gravitational waves with kHz frequencies. We demonstrate that if about one percent of all neutron stars undergo this process, the resulting cosmological gravitational wave background would reach about 10^-10 times the critical density. The background would peak at kHz frequencies and could have an observationally significant tail down to Hz frequencies. It would be comparable or higher than other astrophysical backgrounds, for example, from ordinary core collapse supernovae, from r-mode instabilities in rapidly rotating neutron stars, or from magnetars. The scenario is consistent with cosmological backgrounds in neutrinos and photons.

http://arxiv.org/abs/astro-ph/0602345

[The Messenger]

------------------------------------------------------------------------------
\\
Paper (*cross-listing*): gr-qc/0510077

Date: Sun, 16 Oct 2005 20:54:46 GMT (33kb)

Title: Gravitomagnetism and the Lorentz Invariance of Gravity in the
Gravitational Light-Ray Deflection Experiments

Authors: Sergei M. Kopeikin (University of Missouri-Columbia, USA) and Edward
B. Fomalont (National Radio Astronomy Observatory, USA)

Comments: 25 pages including text, 3 figures and 1 table
\\
Experimental verification of the existence of gravitomagnetic fields
generated by currents of matter is important for a complete understanding and
formulation of gravitational physics. Although the rotational (intrinsic)
gravitomagnetic field has been extensively studied and is now being measured by
the Gravity Probe B, the extrinsic gravitomagnetic field generated by the
translational current of matter is less well studied. The present paper
introduces a fundamental speed of gravity parameter and uses the parametrized
Einstein and light geodesics equations to show that the extrinsic
gravitomagnetic field generated by the translational current of matter can be
measured by observing the relativistic time delay caused by the moving object.
We prove that the extrinsic gravitomagnetic field is measured by the
relativistic effect of the aberration of the gravity force caused by the
Lorentz transformation of the metric tensor and the Levi-Civita connection. We
applied these concepts to the 2002 deflection experiment of a quasar by Jupiter
where the aberration of gravity from its orbital motion was measured with
accuracy 20%. We describe a 2005 experiment to measure the gravitational
deflection of radio waves from a quasar by the sun, as viewed in the geocentric
frame, to improve the measurement accuracy of the aberration of gravity - hence
the fundamental speed of gravity - to a few percent.

\\ ( http://arXiv.org/abs/gr-qc/0510077 , 33kb)

------------------------------------------------------------------------------
\\

IJK-4, this is a little hard to keep up with - would you please ask those submitting abstracts to limit discussion on gravity to a couple of papers a week?

Seriously, this article spells out the how to, rather than what the GR parameter set is. It is interesting that they quote the current value of lamda (2.7x10^-5), and note that it was determined as Cassini passed the limb of the sun. (For GR, lambda should be zero) - I think I have read elsewhere the error bars on the Cassini measurement are on the order of 0+ 2.8x10^-5.