21,965 research outputs found
Using the INSPIRAL program to search for gravitational waves from low-mass binary inspiral
The INSPIRAL program is the LIGO Scientific Collaboration's computational
engine for the search for gravitational waves from binary neutron stars and
sub-solar mass black holes. We describe how this program, which makes use of
the FINDCHIRP algorithm (discussed in a companion paper), is integrated into a
sophisticated data analysis pipeline that was used in the search for low-mass
binary inspirals in data taken during the second LIGO science run.Comment: 11 pages, 3 figures, submitted to Classical and Quantum Gravity for
the special issue of the GWDAW9 Proceeding
Research on utilization of part task spatial orientation information in the dynamic simulator
Error and control efficiency analysis of pilots exposed to simulated pitch, roll, yaw, and altitude variation
Guidance, flight mechanics and trajectory optimization. Volume 2 - Observation theory and sensors
Observation theory and sensors applicable to navigation of boost and space vehicle
Report on the first binary black hole inspiral search in LIGO data
The LIGO Scientific Collaboration is currently engaged in the first search
for binary black hole inspiral signals in real data. We are using the data from
the second LIGO science run and we focus on inspiral signals coming from binary
systems with component masses between 3 and 20 solar masses. We describe the
analysis methods used and report on preliminary estimates for the sensitivities
of the LIGO instruments during the second science run.Comment: 10 pages, 2 figures. Added references for section 2, corrected figure
1. To appear in CQG, in a special issue on the proceedings of the 9th Annual
Gravitational Wave Data Analysis Workshop (GWDAW), Annecy, France, Dec. 200
Guidance, flight mechanics and trajectory optimization. Volume 1 - Coordinate systems and time measure
Coordinate measuring system for flight control, and trajectory optimizatio
Low-speed wind-tunnel investigation of the aerodynamic and acoustic performance of a translating grid choked flow inlet
The aerodynamic and acoustic performance of a translating grid choked-flow inlet was determined in a low-speed wind tunnel at free-stream velocities of 24, 32, and 45 m/sec and incidence angles of 0, 10, 20, 30, 35, 40, 45, and 50 deg. The inlet was sized to fit a 13.97- centimeter-diameter fan with a design weight flow of 2.49 kg/sec. Measurements were made to determine inlet total pressure recovery, flow distortion, and sound pressure level for both choked and unchoked geometries over a range of inlet weight flows. For the unchoked geometry, inlet total pressure recovery ranged from 0.983 to 0.989 at incidence angles less than 40 deg. At 40 deg incidence angle, inlet cowl separation was encountered which resulted in lower values of pressure recovery and higher levels of fan broadband noise. For the choked geometry, increasing total pressure losses occurred with increasing inlet weight flow that prevented the inlet from reaching full choked conditions with the particular fan used. These losses were attributed to the high Mach number drag rise characteristics of airfoil grid. At maximum attainable inlet weight flow, the total pressure recovery at static conditions was 0.935. The fan blade passing frequency and other fan generated pure tones were eliminated from the noise spectrum, but the broadband level was increased
Searches for Gravitational Waves from Binary Neutron Stars: A Review
A new generation of observatories is looking for gravitational waves. These
waves, emitted by highly relativistic systems, will open a new window for ob-
servation of the cosmos when they are detected. Among the most promising
sources of gravitational waves for these observatories are compact binaries in
the final min- utes before coalescence. In this article, we review in brief
interferometric searches for gravitational waves emitted by neutron star
binaries, including the theory, instru- mentation and methods. No detections
have been made to date. However, the best direct observational limits on
coalescence rates have been set, and instrumentation and analysis methods
continue to be refined toward the ultimate goal of defining the new field of
gravitational wave astronomy.Comment: 30 pages, 5 Figures, to appear in "Short-Period Binary Stars:
Observations, Analyses, and Results", Ed.s Eugene F. Milone, Denis A. Leahy,
David W. Hobil
Effects of the R-parity violation in the minimal supersymmetric standard model on dilepton pair production at the CERN LHC
We investigate in detail the effects of the R-parity lepton number violation
in the minimal supersymmetric standard model (MSSM) on the parent process at the CERN Large Hadron Collider (LHC). The numerical
comparisons between the contributions of the R-parity violating effects to the
parent process via the Drell-Yan subprocess and the gluon-gluon fusion are
made. We find that the R-violating effects on pair production at the
LHC could be significant. The results show that the cross section of the pair productions via gluon-gluon collision at the LHC can be of the order
of fb, and this subprocess maybe competitive with the production
mechanism via the Drell-Yan subprocess. We give also quantitatively the
analysis of the effects from both the mass of sneutrino and coupling strength
of the R-parity violating interactions.Comment: 18 pages, 10 figures, accepted by Phys. Rev.
A new numerical method to construct binary neutron star initial data
We present a new numerical method for the generation of binary neutron star
initial data using a method along the lines of the the Wilson-Mathews or the
closely related conformal thin sandwich approach. Our method uses six different
computational domains, which include spatial infinity. Each domain has its own
coordinates which are chosen such that the star surfaces always coincide with
domain boundaries. These properties facilitate the imposition of boundary
conditions. Since all our fields are smooth inside each domain, we are able to
use an efficient pseudospectral method to solve the elliptic equations
associated with the conformal thin sandwich approach. Currently we have
implemented corotating configurations with arbitrary mass ratios, but an
extension to arbitrary spins is possible. The main purpose of this paper is to
introduce our new method and to test our code for several different
configurations.Comment: 18 pages, 8 figures, 1 tabl
Recent results on the search for continuous sources with LIGO and GEO600
An overview of the searches for continuous gravitational wave signals in LIGO
and GEO 600 performed on different recent science runs and results are
presented. This includes both searching for gravitational waves from known
pulsars as well as blind searches over a wide parameter space.Comment: TAUP2005 Proceedings to be published in Journal of Physics:
Conference Serie
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