J. D. E. Creighton
A5090952154- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Geophysics and Sensor Technology
- Seismic Waves and Analysis
- High-pressure geophysics and materials
- Black Holes and Theoretical Physics
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Statistical and numerical algorithms
- Astronomical Observations and Instrumentation
- Seismology and Earthquake Studies
- Relativity and Gravitational Theory
- Noncommutative and Quantum Gravity Theories
- Computational Physics and Python Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic confinement fusion research
- GNSS positioning and interference
- Seismic Imaging and Inversion Techniques
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
University of Wisconsin–Milwaukee
2015-2024
The University of Texas Rio Grande Valley
2016-2024
Brownsville Public Library
2011-2021
Montclair State University
2021
Texas Southmost College
2008-2012
California Institute of Technology
1999-2011
Carleton College
2011
Andrews University
2011
LIGO Scientific Collaboration
2007-2011
Cardiff University
2011
The goal of the Laser Interferometric Gravitational-Wave Observatory (LIGO) is to detect and study gravitational waves (GWs) astrophysical origin. Direct detection GWs holds promise testing general relativity in strong-field regime, providing a new probe exotic objects such as black holes neutron stars uncovering unanticipated astrophysics. LIGO, joint Caltech–MIT project supported by National Science Foundation, operates three multi-kilometer interferometers at two widely separated sites...
Matched-filter searches for gravitational waves from coalescing compact binaries by the LIGO Scientific Collaboration use FINDCHIRP algorithm: an implementation of optimal filter with innovations to account unknown signal parameters and improve performance on detector data that has nonstationary non-Gaussian artifacts. We provide details algorithm as used in search subsolar mass binaries, binary neutron stars, star--black hole black holes.
We investigate the thermodynamical properties of black holes in (3+1)- and (2+1)-dimensional Einstein gravity with a negative cosmological constant. In each case, ther thermodynamic internal energy is computed for finite spatial region that contains hole. The temperature at boundary this regoin defined by differentiating respect to entropy, equal product surface (divided 2\ensuremath{\pi}) Tolman redshift factor stationary gravitational field. also compute pressure and, case 2+1 hole, show...
We report the results of a first study that uses numerical simulations to estimate accuracy with which one can use gravitational wave observations double neutron-star inspiral measure parameters equation state. The evolution and initial-data codes Shibata Ury\ifmmode \bar{u}\else \={u}\fi{} compute last several orbits merger neutron stars, matter described by parametrized Previous work suggested an effective cutoff frequency place constraints on find, however, greater is obtained measuring...
We describe a stream-based analysis pipeline to detect gravitational waves from the merger of binary neutron stars, black holes, and neutron-star-black-hole binaries within ~ 1 minute arrival signal at Earth. Such low-latency detection is crucial for prompt response by electromagnetic facilities in order observe any fading counterparts that might be produced mergers involving least one star. Even systems expected not produce counterparts, data useful deciding when point telescopes, as...
Using an extended set of equations state and a multiple-group multiple-code collaborative effort to generate waveforms, we improve numerical-relativity-based data-analysis estimates the measurability matter effects in neutron-star binaries. We vary two parameters parameterized piecewise-polytropic equation (EOS) analyze EOS properties, via parameter {\Lambda} that characterizes quadrupole deformability isolated neutron star. find that, within accuracy simulations, departure waveform from...
Advanced ground-based gravitational-wave detectors are capable of measuring tidal influences in binary neutron-star systems. In this work, we report on the statistical uncertainties deformability with a full Bayesian parameter estimation implementation. We show how simultaneous measurements chirp mass and can be used to constrain equation state. also study effects waveform modeling bias individual instances detector noise these measurements. notably find that systematic error between...
GstLAL is a stream-based matched-filtering search pipeline aiming at the prompt discovery of gravitational waves from compact binary coalescences such as mergers black holes and neutron stars. Over past three observation runs by LIGO, Virgo, KAGRA Collaboration, has participated in several tens wave discoveries. The fourth observing run (O4) set to begin May 2023 expected see many new interesting signals which will inform our understanding astrophysics cosmology. We describe current...
We consider the stochastic background of gravitational waves produced by a network cosmic strings and assess their accessibility to current planned wave detectors, as well big bang nucleosynthesis (BBN), microwave (CMB), pulsar timing constraints. find that data from interferometric such Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive areas parameter space string models complementary those accessible pulsar, BBN, CMB bounds. Future more LIGO runs interferometers...
One of the most exciting prospects for LISA gravitational wave observatory is detection radiation from inspiral a compact object into supermassive black hole. The large parameter space and low amplitude signal make these sources computationally challenging. We outline here first-cut data analysis scheme that assumes realistic computational resources. In context this scheme, we estimate signal-to-noise ratio source requires to pass our thresholds be detected. Combining with an population in...
We investigate the computational requirements for all-sky, all-frequency searches gravitational waves from spinning neutron stars, using archived data interferometric wave detectors such as LIGO. These sources are expected to be weak, so optimal strategy involves coherent accumulation of signal-to-noise Fourier transforms long stretches (months years). Earth-motion-induced Doppler shifts, and intrinsic pulsar spindown, will reduce narrow-band by spreading power across many frequency bins;...
We examine the properties of an excess power method to detect gravitational waves in interferometric detector data. This is designed short-duration $(\ensuremath{\lesssim}0.5$ s) burst signals unknown waveform, such as those from supernovae or black hole mergers. If only bursts' duration and frequency band are known, optimal detection strategy both Bayesian frequentist senses. It consists summing data over known time interval burst. noise stationary Gaussian, this sum distributed a...
The detection of quasi-periodic sources gravitational waves requires the accumulation signal-to-noise over long observation times. If not removed, Earth-motion induced Doppler modulations, and intrinsic variations gravitational-wave frequency make signals impossible to detect. These effects can be corrected (removed) using a parameterized model for evolution. We compute number independent corrections $N_p(\Delta T,N)$ required incoherent search strategies which use stacked power spectra---a...
A low frequency stochastic background of gravitational waves may be detected by pulsar timing experiments in the next 5 to 10 yr. Using methods developed analyze interferometric wave data, this paper we lay out optimal techniques detect a using array. We show that for distances and frequencies typical experiments, neglecting effect metric perturbation at does not result significant deviation from optimality. discuss setting upper limits statistic, how construct skymaps array, consider...
We present direct upper limits on gravitational wave emission from the Crab pulsar using data first 9 months of fifth science run Laser Interferometer Gravitational-wave Observatory (LIGO). These are based two searches. In we assume that follows observed radio timing, giving an limit beats indirect inferred spin-down and braking index energetics nebula. second allow for a small mismatch between signal frequencies interpret our results in context possible mechanisms.
Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous waves from pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods used are demonstrated in this paper: a frequency domain method time method. Both achieve consistent null results, placing new upper limits on strength of pulsar's emission. A model emission mechanism is to interpret as constraint equatorial...
We report on a search for gravitational waves from coalescing compact binary systems in the Milky Way and Magellanic Clouds. The analysis uses data taken by two of three LIGO interferometers during first science run illustrates method setting upper limits inspiral event rates using interferometer data. pipeline is described with particular attention to selection coincidence between interferometers. establish an observational limit R<1.7×102 per year Equivalent Galaxy (MWEG), 90% confidence,...
We consider an Einstein-Hilbert-Dilaton action for gravity coupled to various types of Abelian and non-Abelian gauge fields in a spatially finite system. These include Yang-Mills with three four-form field strengths. obtain quasilocal quantities associated these fields, including their energy angular momentum, develop methods calculating conserved charges when solution possesses sufficient symmetry. For stationary black holes, we find expression the entropy from micro-canonical form action....
We present upper limits on the gravitational wave emission from 78 radio pulsars based data third and fourth science runs of LIGO GEO 600 detectors. The both have been combined coherently to maximize sensitivity. For first time, within binary (or multiple) systems included in search by taking into account signal modulation due their orbits. Our are therefore measured for 56 these pulsars. remaining 22, our results improve previous up a factor 10. example, tightest limit strain is...
We describe the implementation of a search for gravitational waves from compact binary coalescences in LIGO and Virgo data. This all-sky, all-time, multi-detector coalescence has been used to data taken recent runs. The is built around matched filter analysis data, augmented by numerous signal consistency tests designed distinguish artifacts non-Gaussian detector noise potential detections. demonstrate performance using Gaussian fifth science run that are capable mitigating effect providing...
We analyzed the available LIGO data coincident with GRB 070201, a short-duration, hard-spectrum γ-ray burst (GRB) whose electromagnetically determined sky position is spiral arms of Andromeda galaxy (M31). Possible progenitors such short, hard GRBs include mergers neutron stars or star and black hole, soft repeater (SGR) flares. These events can be accompanied by gravitational-wave emission. No plausible candidates were found within 180 s long window around time 070201. This result implies...
We carry out two searches for periodic gravitational waves using the most sensitive few hours of data from second LIGO science run. The first search is targeted at isolated, previously unknown neutron stars and covers entire sky in frequency band 160-728.8 Hz. targets accreting star low-mass X-ray binary Scorpius X-1, bands 464-484 Hz 604-624 Hz, orbit parameters. Both look coincidences between Livingston Hanford 4-km interferometers. For isolated our 95% confidence upper limits on wave...
We report on a search for gravitational waves from the coalescence of compact binaries during third and fourth LIGO science runs. The focused generated inspiral phase binary evolution. In our analysis, we considered three categories systems, ordered by mass: (i) primordial black hole with masses in range 0.35 M(sun) < m1, m2 1.0 M(sun), (ii) neutron stars 3.0 (iii) holes M(sun)< m_(max) additional constraint m1+ m_(max), where was set to 40.0 80.0 runs, respectively. Although detectors...