3,831 research outputs found
Competition of Color Ferromagnetic and Superconductive States in a Quark-Gluon System
The possibility of color ferromagnetism in an SU(2) gauge field model is
investigated. The conditions allowing a stable color ferromagnetic state of the
quark system in the chromomagnetic field occupying small domains are
considered. A phase transition between this state and the color superconducting
state is considered. The effect of finite temperature is analyzed.Comment: 21 pages, 4 Postscript figure
Coherent Waveform Consistency Test for LIGO Burst Candidates
The burst search in LIGO relies on the coincident detection of transient
signals in multiple interferometers. As only minimal assumptions are made about
the event waveform or duration, the analysis pipeline requires loose
coincidence in time, frequency and amplitude. Confidence in the resulting
events and their waveform consistency is established through a time-domain
coherent analysis: the r-statistic test.
This paper presents a performance study of the r-statistic test for triple
coincidence events in the second LIGO Science Run (S2), with emphasis on its
ability to suppress the background false rate and its efficiency at detecting
simulated bursts of different waveforms close to the S2 sensitivity curve.Comment: 11 pages, 9 figures. Submitted to the Proceedings of the 8th
Gravitational Wave Data Analysis Workshop, in Classic and Quantum Gravit
Gravitational wave burst vetoes in the LIGO S2 and S3 data analyses
The LIGO detectors collected about 4 months of data in 2003-2004 during two
science runs, S2 and S3. Several environmental and auxiliary channels that
monitor the instruments' physical environment and overall interferometric
operation were analyzed in order to establish the quality of the data as well
as the presence of transients of non-astrophysical origin. This analysis
allowed better understanding of the noise character of the instruments and the
establishment of correlations between transients in these channels and the one
recording the gravitational wave strain. In this way vetoes for spurious burst
were identified. We present the methodology we followed in this analysis and
the results from the S2 and S3 veto analysis within the context of the search
for gravitational wave bursts.Comment: 9 pages, 4 figures, submitted to Classical and Quantum Gravity for
the special issue of the GWDAW9 Proceeding
Performance of the WaveBurst algorithm on LIGO data
In this paper we describe the performance of the WaveBurst algorithm which
was designed for detection of gravitational wave bursts in interferometric
data. The performance of the algorithm was evaluated on the test data set
collected during the second LIGO Scientific run. We have measured the false
alarm rate of the algorithm as a function of the threshold and estimated its
detection efficiency for simulated burst waveforms.Comment: proceedings of GWDAW, 2003 conference, 13 pages, 6 figure
A burst search for gravitational waves from binary black holes
Compact binary coalescence (CBC) is one of the most promising sources of
gravitational waves. These sources are usually searched for with matched
filters which require accurate calculation of the GW waveforms and generation
of large template banks. We present a complementary search technique based on
algorithms used in un-modeled searches. Initially designed for detection of
un-modeled bursts, which can span a very large set of waveform morphologies,
the search algorithm presented here is constrained for targeted detection of
the smaller subset of CBC signals. The constraint is based on the assumption of
elliptical polarisation for signals received at the detector. We expect that
the algorithm is sensitive to CBC signals in a wide range of masses, mass
ratios, and spin parameters. In preparation for the analysis of data from the
fifth LIGO-Virgo science run (S5), we performed preliminary studies of the
algorithm on test data. We present the sensitivity of the search to different
types of simulated CBC waveforms. Also, we discuss how to extend the results of
the test run into a search over all of the current LIGO-Virgo data set.Comment: 12 pages, 4 figures, 2 tables, submitted for publication in CQG in
the special issue for the conference proceedings of GWDAW13; corrected some
typos, addressed some minor reviewer comments one section restructured and
references updated and correcte
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