Physical Sciences and Mathematics | Open Access Articles

Directed Search For Continuous Gravitational Waves From The Galactic Center, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We present the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic center region, performed on two years of data from LIGO's fifth science run from two LIGO detectors. The search uses a semicoherent approach, analyzing coherently 630 segments, each spanning 11.5 hours, and then incoherently combining the results of the single segments. It covers gravitational wave frequencies in a range from 78 to 496 Hz and a frequency-dependent range of first-order spindown values down to -7.86×10-8 Hz/s at the highest frequency. No gravitational waves were detected. The 90% confidence upper limits …

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The Transient Gravitational-Wave Sky, Nils Andersson, John Baker, Krzystof Belczynski, Sebastiano Bernuzzi, Emanuele Berti, Laura Cadonati, Pablo Cerdá-Durán, James Clark, Marc Favata, Lee Samuel Finn

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular of the explosive and transient Universe. Now is the time to challenge our theoretical understanding of short-duration gravitational-wave signatures from cataclysmic events, their connection to more traditional electromagnetic and particle astrophysics, and the data analysis techniques that will make the observations a reality. This paper summarizes the state of the art, future science opportunities, and current challenges in understanding gravitational-wave transients.

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Parameter Estimation For Compact Binary Coalescence Signals With The First Generation Gravitational-Wave Detector Network, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and …

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Predicting Unobserved Exposures From Seasonal Epidemic Data, Eric Forgoston, Ira B. Schwartz

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

We consider a stochastic Susceptible-Exposed-Infected-Recovered (SEIR) epidemiological model with a contact rate that fluctuates seasonally. Through the use of a nonlinear, stochastic projection, we are able to analytically determine the lower dimensional manifold on which the deterministic and stochastic dynamics correctly interact. Our method produces a low dimensional stochastic model that captures the same timing of disease outbreak and the same amplitude and phase of recurrent behavior seen in the high dimensional model. Given seasonal epidemic data consisting of the number of infectious individuals, our method enables a data-based model prediction of the number of unobserved exposed individuals over very …

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Enhanced Sensitivity Of The Ligo Gravitational Wave Detector By Using Squeezed States Of Light, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, C. Adams, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Nearly a century after Einstein first predicted the existence of gravitational waves, a global network of Earth-based gravitational wave observatories1-4 is seeking to directly detect this faint radiation using precision laser interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task. Here, we inject squeezed states to improve the performance of one of the detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) beyond the quantum noise limit, most notably in the frequency region down to 150 Hz, critically important for several astrophysical …

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Einstein@Home All-Sky Search For Periodic Gravitational Waves In Ligo S5 Data, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

This paper presents results of an all-sky search for periodic gravitational waves in the frequency range [50,1 190] Hz and with frequency derivative range of ∼[-20,1.1]×10-10 Hz s-1 for the fifth LIGO science run (S5). The search uses a noncoherent Hough-transform method to combine the information from coherent searches on time scales of about one day. Because these searches are very computationally intensive, they have been carried out with the Einstein@Home volunteer distributed computing project. Postprocessing identifies eight candidate signals; deeper follow-up studies rule them out. Hence, since no gravitational wave signals have been found, we report upper limits on …

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Orbitally Paced Shifts In The Particle Size Of Antarctic Continental Shelf Sediments In Response To Ice Dynamics During The Miocene Climatic Optimum, Sandra Passchier, Candice J. Falk, Fabio Florindo

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The AND-2A drill hole (ANDRILL [Antarctic Geological Drilling Program] Southern McMurdo Sound Project), ∼10 km from the East Antarctica coastline, records nearly 6 m.y. of sedimentation across the Miocene climatic optimum at a high-latitude site. Sedimentological studies of bedforms and particle size distributions indicate that the paleoenvironment was strongly affected by waves and currents, consistent with deposition in a glacially influenced neritic environment. We document abrupt shifts in mud percent within glacial-interglacial cycles ca. 17.8 Ma and between ca. 16.7 and 15.7 Ma that we attribute to the hydrodynamic effects of wave stirring tied to episodes of ice growth and …

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Search For Gravitational Waves From Binary Black Hole Inspiral, Merger, And Ringdown In Ligo-Virgo Data From 2009-2010, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We report a search for gravitational waves from the inspiral, merger and ringdown of binary black holes (BBH) with total mass between 25 and 100 solar masses, in data taken at the LIGO and Virgo observatories between July 7, 2009 and October 20, 2010. The maximum sensitive distance of the detectors over this period for a (20,20)MâŠ™ coalescence was 300 Mpc. No gravitational wave signals were found. We thus report upper limits on the astrophysical coalescence rates of BBH as a function of the component masses for nonspinning components, and also evaluate the dependence of the search sensitivity on component …

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A First Search For Coincident Gravitational Waves And High Energy Neutrinos Using Ligo, Virgo And Antares Data From 2007, S. Adrián-Martínez, I. Al Samarai, A. Albert, M. André, M. Anghinol, G. Anton, S. Anvar, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place …

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Early Eocene To Middle Miocene Cooling And Aridification Of East Antarctica, Sandra Passchier, Steven M. Bohaty, Francisco J. Jiménez‐Espejo, Jörg Pross, Ursu Röhl, Tina Van De Flierdt, Carlota Escutia, Henk Brinkhuis

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

[1] Few high‐latitude terrestrial records document the timing and nature of the Cenozoic “Greenhouse” to “Icehouse” transition. Here we exploit the bulk geochemistry of marine siliciclastic sediments from drill cores on Antarctica's continental margin to extract a unique semiquantitative temperature and precipitation record for Eocene to mid‐Miocene (~54–13 Ma). Alkaline elements are strongly enriched in the detrital mineral fraction in fine‐grained siliciclastic marine sediments and only occur as trace metals in the biogenic fraction. Hence, terrestrial climofunctions similar to the chemical index of alteration (CIA) can be applied to the alkaline major element geochemistry of marine sediments on continental margins …

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Oil Pollution In Water Bodies Of Restricted Circulation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Coastal lagoons and embayments near urban centers around the world share many common characteristics and problems. Physical impediments to free water circulation (spits, barrier islands, internal islands, tombolos, submerged sills) often lead to water stagnation and, in the presence of excess nutrients, eutrophication. Urban and industrial activities provoke (usually accidental) spills of hazardous materials into these confined water bodies, such as crude petroleum and refined petroleum products, leading to difficulties for resident biota and potential hazards for human health. The sluggish turnover of these water bodies (or low-energy zones within them) may retard the natural attenuation of the spilled contaminants. …

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Decision Support In Data Centers For Sustainability, Michael Pawlish, Aparna Varde, Stefan Robila

Department of Computer Science Faculty Scholarship and Creative Works

In this paper, we propose a decision support system (DSS) for the greening of data centers to help the environment, hence promoting sustainability. As society continues the relentless shift towards electronic communications there is a growing demand for greater storage and processing on data centers. A potential area of improvement is to gain greater server utilization rates since traditionally the phenomenon of 'server sprawl' occurs where more servers are added to the data center without seeking greater utilization rates on existing servers first. This implies maintaining more servers than actually needed that translates to greater carbon dioxide emissions causing potential …

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Energy-Aware Scheduling For Acyclic Synchronous Data Flows On Multiprocessors, Dawei Li, Jie Wu

Department of Computer Science Faculty Scholarship and Creative Works

Synchronous Data Flow (SDF) is a useful computational model in image processing, computer vision, and DSP. Previously, throughput and buffer requirement analyses have been studied for SDFs. In this paper, we address energy-aware scheduling for acyclic SDFs on multiprocessors. The multiprocessor considered here has the capability of Dynamic Voltage and Frequency Scaling (DVFS), which allows processors to operate at different power/energy levels to reduce the energy consumption. An acyclic SDF graph can first be transformed to an equivalent homogeneous SDF graph and then to a Directed Acyclic Graph (DAG) for one iteration of it. We propose pipeline scheduling to address …

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Full-Text Articles in Physical Sciences and Mathematics

Directed Search For Continuous Gravitational Waves From The Galactic Center, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

The Transient Gravitational-Wave Sky, Nils Andersson, John Baker, Krzystof Belczynski, Sebastiano Bernuzzi, Emanuele Berti, Laura Cadonati, Pablo Cerdá-Durán, James Clark, Marc Favata, Lee Samuel Finn

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Parameter Estimation For Compact Binary Coalescence Signals With The First Generation Gravitational-Wave Detector Network, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Predicting Unobserved Exposures From Seasonal Epidemic Data, Eric Forgoston, Ira B. Schwartz

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

Enhanced Sensitivity Of The Ligo Gravitational Wave Detector By Using Squeezed States Of Light, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, C. Adams, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Einstein@Home All-Sky Search For Periodic Gravitational Waves In Ligo S5 Data, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Orbitally Paced Shifts In The Particle Size Of Antarctic Continental Shelf Sediments In Response To Ice Dynamics During The Miocene Climatic Optimum, Sandra Passchier, Candice J. Falk, Fabio Florindo

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Search For Gravitational Waves From Binary Black Hole Inspiral, Merger, And Ringdown In Ligo-Virgo Data From 2009-2010, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

A First Search For Coincident Gravitational Waves And High Energy Neutrinos Using Ligo, Virgo And Antares Data From 2007, S. Adrián-Martínez, I. Al Samarai, A. Albert, M. André, M. Anghinol, G. Anton, S. Anvar, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Early Eocene To Middle Miocene Cooling And Aridification Of East Antarctica, Sandra Passchier, Steven M. Bohaty, Francisco J. Jiménez‐Espejo, Jörg Pross, Ursu Röhl, Tina Van De Flierdt, Carlota Escutia, Henk Brinkhuis

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Oil Pollution In Water Bodies Of Restricted Circulation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Decision Support In Data Centers For Sustainability, Michael Pawlish, Aparna Varde, Stefan Robila

Department of Computer Science Faculty Scholarship and Creative Works

Energy-Aware Scheduling For Acyclic Synchronous Data Flows On Multiprocessors, Dawei Li, Jie Wu

Department of Computer Science Faculty Scholarship and Creative Works