Recursos de colección

Caltech Authors (167.915 recursos)

Repository of works by Caltech published authors.

Group = LIGO

Mostrando recursos 1 - 20 de 617

  1. Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Biscans, S; Blackburn, J. K.; Blair, C. D.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Coughlin, M. W.; Couvares, P.; Coyne, D. C.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Heptonstall, A. W.; Isi, M.; Kamai, B.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Markowitz, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Nevin, L.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Sanchez, L. E.; Schmidt, P.; Smith, R. J. E.; Taylor, R.; Torrie, C. I.; Tso, R.; Urban, A. L.; Vajente, G.; Vass, S.; Venugopalan, G.; Wade, A. R.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Willis, J. L.; Wipf, C. C.; Xiao, S.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.; Barkett, K.; Blackman, J.; Chen, Y.; Ma, Y.; Pang, B.; Scheel, M.; Varma, V.
    The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find...

  2. Full band all-sky search for periodic gravitational waves in the O1 LIGO data

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Biscans, S; Blackburn, J. K.; Blair, C. D.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Heptonstall, A. W.; Isi, M.; Kamai, B.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Markowitz, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Nevin, L.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Sanchez, L. E.; Schmidt, P.; Smith, R. J. E.; Taylor, R.; Torrie, C. I.; Tso, R.; Urban, A. L.; Vajente, G.; Vass, S.; Venugopalan, G.; Wade, A. R.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Willis, J. L.; Wipf, C. C.; Xiao, S.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.; Barkett, K.; Blackman, J.; Chen, Y.; Ma, Y.; Pang, B.; Scheel, M.; Varma, V.
    We report on a new all-sky search for periodic gravitational waves in the frequency band 475–2000 Hz and with a frequency time derivative in the range of [−1.0,+0.1]×10^(−8)  Hz/s. Potential signals could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. This search uses the data from Advanced LIGO’s first observational run O1. No gravitational-wave signals were observed, and upper limits were placed on their strengths. For completeness, results from the separately published low-frequency search 20–475 Hz are included as well. Our lowest upper limit on worst-case (linearly polarized) strain amplitude h_0 is ∼4×10^(−25) near...

  3. Constraints on cosmic strings using data from the first Advanced LIGO observing run

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Hall, E. D.; Heptonstall, A. W.; Isi, M.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Maros, E.; Massinger, T. J.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Schmidt, P.; Singer, A.; Smith, R. J. E.; Taylor, R.; Torrie, C. I.; Tso, R.; Urban, A. L.; Vajente, G.; Vass, S.; Venugopalan, G.; Wade, A. R.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.; Blackman, J.; Chen, Y.; Ma, Y.; Pang, B.; Thorne, K. S.; Vallisneri, M.; Varma, V.
    Cosmic strings are topological defects which can be formed in grand unified theory scale phase transitions in the early universe. They are also predicted to form in the context of string theory. The main mechanism for a network of Nambu-Goto cosmic strings to lose energy is through the production of loops and the subsequent emission of gravitational waves, thus offering an experimental signature for the existence of cosmic strings. Here we report on the analysis conducted to specifically search for gravitational-wave bursts from cosmic string loops in the data of Advanced LIGO 2015-2016 observing run (O1). No evidence of such...

  4. Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Biscans, S; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Hall, E. D.; Heptonstall, A. W.; Isi, M.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Schmidt, P.; Singer, A.; Smith, R. J. E.; Taylor, R.; Torrie, C. I.; Tso, R.; Urban, A. L.; Vajente, G.; Vass, S.; Venugopalan, G.; Wade, A. R.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.; Blackman, J.; Chen, Y.; Ma, Y.; Varma, V.
    We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources...

  5. Optimizing Workflow Data Footprint

    Singh, Gurmeet; Vahi, Karan; Ramakrishnan, Arun; Mehta, Gaurang; Deelman, Ewa; Zhao, Henan; Sakellariou, Rizos; Blackburn, Kent; Brown, Duncan; Fairhurst, Stephen; Meyers, David; Berriman, G. Bruce; Good, John; Katz, Daniel S.
    In this paper we examine the issue of optimizing disk usage and scheduling large-scale scientific workflows onto distributed resources where the workflows are data-intensive, requiring large amounts of data storage, and the resources have limited storage resources. Our approach is two-fold: we minimize the amount of space a workflow requires during execution by removing data files at runtime when they are no longer needed and we demonstrate that workflows may have to be restructured to reduce the overall data footprint of the workflow. We show the results of our data management and workflow restructuring solutions using a Laser Interferometer Gravitational-Wave...

  6. Identification and mitigation of narrow spectral artifacts that degrade searches for persistent gravitational waves in the first two observing runs of Advanced LIGO

    Covas, P. B.; Callister, T. A.; Coughlin, M. W.; McIver, J.; Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Appert, S.; Arai, K.; Billingsley, G.; Bork, R.; Brooks, A. F.; Coyne, D. C.; Etzel, T.; Gushwa, K. E.; Gustafson, E. K.; Heptonstall, A. W.; Korth, W. Z.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sanchez, E. J.; Sanchez, L. E.; Taylor, R.; Torrie, C. I.; Vajente, G.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.
    Searches are under way in Advanced LIGO and Virgo data for persistent gravitational waves from continuous sources, e.g. rapidly rotating galactic neutron stars, and stochastic sources, e.g. relic gravitational waves from the Big Bang or superposition of distant astrophysical events such as mergers of black holes or neutron stars. These searches can be degraded by the presence of narrow spectral artifacts (lines) due to instrumental or environmental disturbances. We describe a variety of methods used for finding, identifying and mitigating these artifacts, illustrated with particular examples. Results are provided in the form of lists of line artifacts that can safely...

  7. Optimal Search for an Astrophysical Gravitational-Wave Background

    Smith, Rory; Thrane, Eric
    Roughly every 2–10 min, a pair of stellar-mass black holes merge somewhere in the Universe. A small fraction of these mergers are detected as individually resolvable gravitational-wave events by advanced detectors such as LIGO and Virgo. The rest contribute to a stochastic background. We derive the statistically optimal search strategy (producing minimum credible intervals) for a background of unresolved binaries. Our method applies Bayesian parameter estimation to all available data. Using Monte Carlo simulations, we demonstrate that the search is both “safe” and effective: it is not fooled by instrumental artifacts such as glitches and it recovers simulated stochastic signals...

  8. Reconstructing the calibrated strain signal in the Advanced LIGO detectors

    Viets, A. D.; Wade, M.; Urban, A. L.; Kandhasamy, S.; Betzwieser, J.; Brown, Duncan A.; Burguet-Castell, J.; Cahillane, C.; Goetz, E.; Izumi, K.; Karki, S.; Kissel, J. S.; Mendell, G.; Savage, R. L.; Siemens, X.; Tuyenbayev, D.; Weinstein, A. J.
    Advanced LIGO's raw detector output needs to be calibrated to compute dimensionless strain h(t). Calibrated strain data is produced in the time domain using both a low-latency, online procedure and a high-latency, offline procedure. The low-latency h(t) data stream is produced in two stages, the first of which is performed on the same computers that operate the detector's feedback control system. This stage, referred to as the front-end calibration, uses infinite impulse response (IIR) filtering and performs all operations at a 16 384 Hz digital sampling rate. Due to several limitations, this procedure currently introduces certain systematic errors in the calibrated...

  9. Observational implications of lowering the LIGO-Virgo alert threshold

    Lynch, Ryan; Coughlin, Michael; Vitale, Salvatore; Stubbs, Christopher W.; Katsavounidis, Erik
    The recent detection of the binary-neutron-star merger associated with GW170817 by both LIGO- Virgo and the network of electromagnetic-spectrum observing facilities around the world has made the multi-messenger detection of gravitational-wave events a reality. These joint detections allow us to probe gravitational-wave sources in greater detail and provide us with the possibility of confidently establishing events that would not have been detected in gravitational-wave data alone. In this paper, we explore the prospects of using the electromagnetic follow-up of low-significance gravitational-wave transient event candidates to increase the sample of confident detections with electromagnetic counterparts. We find that the gravitational-wave alert threshold change that would roughly double the number of detectable astrophysical...

  10. Gravitational waves from hyper-accretion on to nascent black holes

    Araya-Góchez, Rafael A.
    We examine the possibility that hyper-accretion on to newly born black holes occurs in highly intermittent, non-asymmetric fashion favourable to gravitational-wave emission in a neutrino-cooled disc. This picture of near-hole accretion is motivated by magnetorotationally induced, ultrarelativistic disc dynamics in the region of the flow bounded from below by the marginally bound geodesic radius rmb. For high spin values, a largely coherent magnetic field in this region has the dynamical implication of compact mass segregation at the displacement nodes of the non-axisymmetric, magnetorotational instability modes. When neutrino stress competes favourably for the disc dynamical structure, the matter clumps may be...

  11. Investigation of violin mode Q for wires of various materials

    Dawid, Daryush J.; Kawamura, Seiji
    The QQ factors of violin modes for wires of various materials have been measured in order to determine which would be most suitable for use in the suspension of test masses in the initial laser interferometer gravitational wave observatory (LIGO) interferometers. A “guitar” type apparatus was employed to measure violin mode QQs, and losses due to clamping and other practical sources were successfully suppressed below the level of intrinsic wire losses. Steel music wire was found to give the highest extrapolated QQ factors under LIGO conditions among the wires we tested. This extrapolated QQ sets a target for the LIGO...

  12. Effect of elevated substrate temperature deposition on the mechanical losses in tantala thin film coatings

    Vajente, G.; Ananyeva, A.; Billingsley, G.; Gustafson, E.; Heptonstall, A.; Torrie, C.; Adhikari, R. X.
    Brownian thermal noise in dielectric multilayer coatings limits the sensitivity of current and future interferometric gravitational wave detectors. In this work we explore the possibility of improving the mechanical losses of tantala, often used as the high refractive index material, by depositing it on a substrate held at elevated temperature. Promising results have been previously obtained with this technique when applied to amorphous silicon. We show that depositing tantala on a hot substrate reduced the mechanical losses of the as-deposited coating, but subsequent thermal treatments had a larger impact, as they reduced the losses to levels previously reported in the...

  13. BOSS-LDG: A Novel Computational Framework That Brings Together Blue Waters, Open Science Grid, Shifter and the LIGO Data Grid to Accelerate Gravitational Wave Discovery

    Huerta, E. A.; Haas, Roland; Fajardo, Edgar; Katz, Daniel S.; Anderson, Stuart; Couvares, Peter; Willis, Josh; Bouvet, Timothy; Enos, Jeremy; Kramer, William T. C.; Leong, Hon Wai; Wheeler, David
    We present a novel computational framework that connects Blue Waters, the NSF-supported, leadership-class supercomputer operated by NCSA, to the Laser Interferometer Gravitational-Wave Observatory (LIGO) Data Grid via Open Science Grid technology. To enable this computational infrastructure, we configured, for the first time, a LIGO Data Grid Tier-1 Center that can submit heterogeneous LIGO workflows using Open Science Grid facilities. In order to enable a seamless connection between the LIGO Data Grid and Blue Waters via Open Science Grid, we utilize Shifter to containerize LIGO's workflow software. This work represents the first time Open Science Grid, Shifter, and Blue Waters are...

  14. Physics of interferometric gravitational wave detectors

    Bhawal, Biplab
    The Caltech-MIT joint LIGO project is operating three long-baseline interferometers (one of 2 km and two of 4 km) in order to unambiguously measure the infinitesimal displacements of isolated test masses which convey the signature of gravitational waves from astrophysical sources. An interferometric gravitational wave detector like LIGO is a complex, non-linear, coupled, dynamic system. This article summarizes various interesting design characteristics of these detectors and techniques that were implemented in order to reach and maintain its operating condition. Specifically, the following topics are discussed: (i) length sensing and control, (ii) alignment sensing and control and (iii) thermal lensing which...

  15. Searches for gravitational waves from known pulsars with S5 LIGO data

    Abbott, B. P.; Abbott, R.; Adhikari, R.; Anderson, S. B.; Araya, M.; Armandula, H.; Aso, Y.; Ballmer, S.; Barton, M. A.; Betzwieser, J.; Billingsley, G.; Black, E.; Blackburn, J. K.; Bork, R.; Boschi, V.; Brooks, A. F.; Cannon, K. C.; Cardenas, L.; Cepeda, C.; Chalermsongsak, T.; Chatterji, S.; Coyne, D. C.; Daubert, B.; DeSalvo, R.; Echols, C.; Ehrens, P.; Espinoza, E.; Etzel, T.; Fazi, D.; Gustafson, E. K.; Hanna, C.; Heefner, J.; Heptonstall, A.; Hodge, K. A.; Ivanov, A.; Kalmus, P.; Kells, W.; Keppel, D. G.; King, P.; Kondrashov, V.; Kozak, D.; Lazzarini, A.; Lei, M.; Lindquist, P. E.; Mageswaran, M.; Mailand, K.; Maros, E.; Marx, J. N.; McIntyre, G.; Meshkov, S.; Miyakawa, O.; Nash, T.; Ogin, G. H.; Patel, P.; Pedraza, M.; Robertson, N. A.; Russell, P.; Sannibale, V.; Searle, A. C.; Sears, B.; Sengupta, A. S.; Smith , M. R.; Stochino, A.; Taylor, R.; Torrie, C.; Vass, S.; Villar, A.; Wallace, L.; Ward, R. L.; Weinstein, A. J.; Whitcomb, S. E.; Willems, P. A.; Yamamoto, H.; Zhang, L.; Zweizig, J.; Chen, Y.; Li , C.; Mino, Y.; Savov, P.; Somiya, K.; Thorne, K. S.; Vallisneri, M.; Wen, L.; Drever, R. W. P.
    We present a search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors. For this search, ephemerides overlapping the run period were obtained for all pulsars using radio and X-ray observations. We demonstrate an updated search method that allows for small uncertainties in the pulsar phase parameters to be included in the search. We report no signal detection from any of the targets and therefore interpret our results as upper limits on the gravitational wave signal strength. The most interesting limits are those for young pulsars. We present...

  16. Optimal filtering of the LISA data

    Królak, Andrzej; Tinto, Massimo; Vallisneri, Michele
    The LISA time-delay-interferometry responses to a gravitational wave signal are rewritten in a form that accounts for the motion of the LISA constellation around the Sun; the responses are given in closed analytic forms valid for any frequency in the band accessible to LISA. We then present a complete procedure, based on the principle of maximum likelihood, to search for stellar-mass binary systems in the LISA data. We define the required optimal filters, the amplitude-maximized detection statistic (analogous to the Ƒ statistic used in pulsar searches with ground-based interferometers), and discuss the false-alarm and detection probabilities. We then test the...

  17. Analysis of a quantum nondemolition speed-meter interferometer

    Purdue, Patricia
    In the quest to develop viable designs for third-generation optical interferometric gravitational-wave detectors (e.g. LIGO-III and EURO), one strategy is to monitor the relative momentum or speed of the test-mass mirrors rather than monitoring their relative position. This paper describes and analyzes the most straightforward design for a speed meter interferometer that accomplishes this—a design (due to Braginsky, Gorodetsky, Khalili and Thorne) that is analogous to a microwave-cavity speed meter conceived by Braginsky and Khalili. A mathematical mapping between the microwave speed meter and the optical interferometric speed meter is developed and is used to show [in accord with the...

  18. Mathematical framework for simulation of quantum fields in complex interferometers using the two-photon formalism

    Corbitt, Thomas; Chen, Yanbei; Mavalvala, Nergis
    We present a mathematical framework for simulation of optical fields in complex gravitational-wave interferometers. The simulation framework uses the two-photon formalism for optical fields and includes radiation pressure effects, an important addition required for simulating signal and noise fields in next-generation interferometers with high circulating power. We present a comparison of results from the simulation with analytical calculation and show that accurate agreement is achieved.

  19. Explaining LIGO’s observations via isolated binary evolution with natal kicks

    Wysocki, Daniel; Gerosa, Davide; O’Shaughnessy, Richard; Belczynski, Krzysztof; Gladysz, Wojciech; Berti, Emanuele; Kesden, Michael; Holz, Daniel E.
    We compare binary evolution models with different assumptions about black-hole natal kicks to the first gravitational-wave observations performed by the LIGO detectors. Our comparisons attempt to reconcile merger rate, masses, spins, and spin-orbit misalignments of all current observations with state-of-the-art formation scenarios of binary black holes formed in isolation. We estimate that black holes (BHs) should receive natal kicks at birth of the order of σ ≃ 200 (50) km/s if tidal processes do (not) realign stellar spins. Our estimate is driven by two simple factors. The natal kick dispersion σ is bounded from above because large kicks disrupt too...

  20. Parametrized tests of the strong-field dynamics of general relativity using gravitational wave signals from coalescing binary black holes: Fast likelihood calculations and sensitivity of the method

    Meidam, Jeroen; Tsang, Ka Wa; Goldstein, Janna; Agathos, Michalis; Ghosh, Archisman; Haster, Carl-Johan; Raymond, Vivien; Samajdar, Anuradha; Schmidt, Patricia; Smith, Rory; Blackburn, Kent; Del Pozzo, Walter; Field, Scott E.; Li, Tjonnie; Pürrer, Michael; Van Den Broeck, Chris; Veitch, John; Vitale, Salvatore
    Thanks to the recent discoveries of gravitational wave signals from binary black hole mergers by Advanced Laser Interferometer Gravitational Wave Observatory and Advanced Virgo, the genuinely strong-field dynamics of spacetime can now be probed, allowing for stringent tests of general relativity (GR). One set of tests consists of allowing for parametrized deformations away from GR in the template waveform models and then constraining the size of the deviations, as was done for the detected signals in previous work. In this paper, we construct reduced-order quadratures so as to speed up likelihood calculations for parameter estimation on future events. Next, we...

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