A5065852656- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Geophysics and Sensor Technology
- Seismic Waves and Analysis
- Advanced Frequency and Time Standards
- Seismology and Earthquake Studies
- Radio Astronomy Observations and Technology
- High-pressure geophysics and materials
- Black Holes and Theoretical Physics
- Statistical and numerical algorithms
- Astronomical Observations and Instrumentation
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Quantum Electrodynamics and Casimir Effect
- Cold Atom Physics and Bose-Einstein Condensates
- Target Tracking and Data Fusion in Sensor Networks
- Computational Physics and Python Applications
- Neutrino Physics Research
- Magnetic confinement fusion research
Cardiff University
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2018
California Institute of Technology
2004-2008
Max Planck Society
2008
Max Planck Innovation
2008
The University of Western Australia
2008
LIGO Scientific Collaboration
2007
Pennsylvania State University
2001-2006
University of Alberta
1999-2000
University College London
2000
Abstract We report the discovery and monitoring of near-infrared counterpart (AT2017gfo) a binary neutron-star merger event detected as gravitational wave source by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo (GW170817) short gamma-ray burst Fermi Gamma-ray Burst Monitor (GBM) Integral SPI-ACS (GRB 170817A). The evolution transient light is consistent with predictions for behavior “kilonova/macronova” powered radioactive decay massive neutron-rich nuclides...
Abstract We present Hubble Space Telescope ( HST ) and Chandra imaging, combined with Very Large MUSE integral field spectroscopy of the counterpart host galaxy first binary neutron star merger detected via gravitational-wave emission by LIGO Virgo, GW170817. The galaxy, NGC 4993, is an S0 at z = 0.009783. There evidence for large, face-on spiral shells in continuum edge-on features visible nebular lines. This suggests that 4993 has undergone a relatively recent <mml:math...
The next galactic core-collapse supernova (CCSN) has already exploded, and its electromagnetic (EM) waves, neutrinos, gravitational waves (GWs) may arrive at any moment. We present an extensive study on the potential sensitivity of prospective detection scenarios for GWs from CCSNe within 5 Mpc, using realistic noise predicted Advanced LIGO Virgo detectors 2015, 2017, 2019. quantify detectability Milky Way Large Magellanic Cloud, which there will be observed neutrino burst. also consider...
The close agreement between the predictions of dynamical general relativity for radiated power a compact binary system and observed orbital decay pulsars PSR B1913+16 B1534+12 allows us to bound graviton mass be less than 7.6 x 10^{-20} eV with 90% confidence. This is first obtained from dynamic, as opposed static-field, relativity. resulting limit on within two orders magnitude that solar measurements, can expected improve further observations.
Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters gravitational waves high-energy cosmic radiation, including photons, hadrons, presumably also neutrinos. Both (GW) neutrinos (HEN) messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from inner regions engines which they emitted (and photons charged rays cannot reach us). For same reasons, such could reveal...
Convolutional neural networks (CNNs) have demonstrated potential for the real-time analysis of data from gravitational wave detector specific case signals coalescing compact-object binaries such as black-hole binaries. Unfortunately, CNNs presented to date required a precise model target signal training. Such are therefore not applicable detecting generic transients unknown sources, and may be unreliable anticipated sources core-collapse supernovae long gamma-ray bursts, where physics or...
The sensitivity of current searches for gravitational-wave bursts is limited by non-Gaussian, nonstationary noise transients which are common in real detectors. Existing techniques detecting assume the output detector network to be sum a stationary Gaussian process and signal. These often fail presence nonstationarities incorrectly identifying such as possible bursts. Furthermore, consistency tests currently used try eliminate these not applicable general networks detectors with different...
Autonomous gravitational-wave searches—fully automated analyses of data that run without human intervention or assistance—are desirable for a number reasons. They are necessary the rapid identification burst candidates, which in turn will allow follow-up observations by other observatories and maximum exploitation their scientific potential. A fully analysis would also circumvent traditional 'by hand' setup tuning searches is both labourious time consuming. We demonstrate search with...
Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular explosive transient Universe. Now is time to challenge our theoretical understanding short-duration signatures from cataclysmic events, their connection more traditional electromagnetic particle astrophysics, data analysis techniques that make observations a reality. This paper summarizes state art, future science opportunities, current challenges transients.
Perturbative QCD is used to predict the deep-inelastic electron-proton structure functions ${F}_{T,L}(x, {Q}^{2})$ in small $x$ region ($x\ensuremath{\sim}{10}^{\ensuremath{-}3}$) from an experimental knowledge of behavior at larger $x$. Shadowing corrections are quantified.
Rats transmit information to each other about which foods are safe eat. If a rat smells food odor on the breath of another rat, it is subsequently more likely eat that than an alternative. Work byGalef et al. (1988) has shown observer forms association between two olfactory stimuli demonstrator eaten food, and carbon disulphide, normally present in breath. Bunsey Eichenbaum (1995) claimed hippocampus/subicular region required for long-term retention this nonspatial form associative memory...
We examine the proposal that deep-inelastic ($x,{Q}^{2}$) scattering events which contain an identified jet, with transverse momentum squared ${k}^{2}\ensuremath{\simeq}{Q}^{2}$, allow ideal determination of QCD behavior at very small $x$. solve Lipatov equation to predict shape jet spectrum in such and show measurements DESY $\mathrm{ep}$ collider HERA should be able verify, inter alia, whether gluon indeed has theoretically anticipated...
We present the baseline multimessenger analysis method for joint observations of gravitational waves (GW) and high-energy neutrinos (HEN), together with a detailed expected science reach search. The combines data from GW HEN detectors, uses blue-luminosity-weighted distribution galaxies. derive GW+HEN source rate upper limits wide range parameters covering several emission models. Using published sensitivities externally triggered searches, we limit estimates both ongoing initial LIGO-Virgo...
We present the performance of searches for gravitational-wave bursts associated with external astrophysical triggers as a function search sky region. discuss both case Gaussian noise and real gravitational wave detectors arbitrary detector networks. demonstrate ability to reach limited sensitivity in non-Gaussian data, show conditions required attain it. find that single position is $\ensuremath{\sim}20%$ more sensitive than an all-sky same data.
The binary neutron star merger GW170817 was the first multi-messenger event observed in both gravitational and electromagnetic waves. signal began approximately 2 seconds post-merger with a weak, short burst of gamma-rays, which followed over next hours days by ultraviolet, optical near-infrared emission from radioactively- powered kilonova. Later, non-thermal rising X-ray radio observed. low luminosity gamma-rays flux source at late times could indicate that we are outside opening angle...
One of the goals current LIGO-GEO-Virgo science run is to identify transient gravitational wave (GW) signals in near real time allow follow-up electromagnetic (EM) observations. An EM counterpart could increase confidence GW detection and provide insight into nature source. Current GW-EM campaigns target potential host galaxies based on overlap with sky error box. We propose a new statistic most likely galaxy, ranking their position, distance, luminosity. test our Monte Carlo simulations GWs...
A massless scalar field minimally coupled to gravity and propagating in Schwarzschild spacetime is considered. After dimensional reduction under spherical symmetry the resulting 2D theory canonically quantized renormalized expectation values $〈{T}_{\mathrm{ab}}〉$ of relevant energy-momentum tensor operator are investigated. Asymptotic behaviors analytical approximations given for Boulware, Unruh Hartle-Hawking states. Special attention devoted black-hole horizon region where WKB...
In a wide class of D-dimensional spacetimes which are direct or semi-direct sums $(D\ensuremath{-}n)$-dimensional space and an n-dimensional homogeneous ``internal'' space, field can be decomposed into modes. As result this mode decomposition, the main objects characterize free quantum field, such as Green functions heat kernels, effectively reduced to in spacetime with external dilaton field. We study problem dimensional reduction effective action for spacetimes. While before...
The genetic algorithm is presented as a straightforward computerized search method capable of solving problems from wide variety problem domains. A brief overview the mechanics presented, and results its application to function optimization, determination ground state energies spin glass related models are shown.
The data analysis problem of coherently searching for unmodeled gravitational-wave bursts in the generated by a global network observatories has been at center research almost two decades. As from these detectors are starting to be analyzed, renewed interest this sparked. A Bayesian approach gravitational wave with ground-based interferometers is presented here. We demonstrate how systematically incorporate prior information on burst signal and its source into analysis. This may range very...