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- Physics and Astronomy Faculty Publications and Presentations (20)
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Articles 1 - 30 of 34
Full-Text Articles in Physical Sciences and Mathematics
Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen
Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
In the buildup to the construction the U.S.-Mexico border fence by the United States Department of Homeland Security (USDHS), much attention was drawn to security, drug enforcement, and immigration issues. However, there was little quantitative analysis regarding which populations were most likely to be affected by the proposed fence. Using a geographic information system, we classified census blocks in Cameron County, Texas into one of two categories: either ‘fence’ or ‘gap’. A total of 14 demographic factors were tested for disparities between those living in gap areas and those living in areas exposed to the fence. Twelve of fourteen factors …
Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen
Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen
Physics and Astronomy Faculty Publications and Presentations
The equation of state of a system of fermions in a uniform magnetic field is obtained in terms of the thermodynamic quantities of the theory by using functional methods. It is shown that the breaking of the O(3) rotational symmetry by the magnetic field results in a pressure anisotropy, which leads to the distinction between longitudinal- and transverse-to-the-field pressures. A criterion to find the threshold field at which the asymmetric regime becomes significant is discussed. This threshold magnetic field is shown to be the same as the one required for the pure field contribution to the energy and pressures to …
Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik
Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik
Physics and Astronomy Faculty Publications and Presentations
We study the Galactic field population of double compact objects (DCOs; NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with the Laser Interferometer Space Antenna (LISA) at low gravitational wave frequencies. We calculate the Galactic numbers and physical properties of these binaries and show their relative contributions from the disk, bulge, and halo. Although the Galaxy hosts ∼10 5 DCO binaries emitting low-frequency gravitational waves, only a handful of these objects in the disk will be detectable with LISA, but none from the halo or bulge. This is because the …
A Highly Efficient Bismuth Salts-Catalyzed Route For The Synthesis Of Alpha-Aminophosphonates, Antara Banik, Sahil Batta, Debasish Bandyopadhyay, Bimal K. Banik
A Highly Efficient Bismuth Salts-Catalyzed Route For The Synthesis Of Alpha-Aminophosphonates, Antara Banik, Sahil Batta, Debasish Bandyopadhyay, Bimal K. Banik
Chemistry Faculty Publications and Presentations
A convenient synthesis of different types of α-amino phosphonates via one-pot solvent-free three component reactions of aldehydes, amines and phosphites catalyzed by bismuth salts has been investigated. Bismuth triflate is found to be the most effective catalyst for this reaction.
Importance Of Electronic Relaxation For Inter-Coulombic Decay In Aqueous Systems, Craig P. Schwartz, Shervin Fatehi, Richard J. Saykally, David Prendergast
Importance Of Electronic Relaxation For Inter-Coulombic Decay In Aqueous Systems, Craig P. Schwartz, Shervin Fatehi, Richard J. Saykally, David Prendergast
Chemistry Faculty Publications and Presentations
Inspired by recent photoelectron spectroscopy experiments on hydroxide solutions, we have examined the conditions necessary for enhanced (and, in the case of solutions, detectable) inter-Coulombic decay (ICD)—Auger emission from an atomic site other than that originally excited. We present general guidelines, based on energetic and spatial overlap of molecular orbitals, for this enhancement of inter-Coulombic decay-based energy transfer in solutions. These guidelines indicate that this decay process should be exhibited by broad classes of biomolecules and suggest a design criterion for targeted radiooncology protocols. Our findings show that photoelectron spectroscopy cannot resolve the current hydroxide coordination controversy.
First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, M. Aronsson, Y. Aso, S. Aston, D. E. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, D. Barker, S. Barnum, B. Barr, P. Barriga, L. Barsotti, M. A. Barton
First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, M. Aronsson, Y. Aso, S. Aston, D. E. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, D. Barker, S. Barnum, B. Barr, P. Barriga, L. Barsotti, M. A. Barton
Physics and Astronomy Faculty Publications and Presentations
We present a search for periodic gravitational waves from the neutron star in the supernova remnant Cassiopeia A. The search coherently analyzes data in a 12 day interval taken from the fifth science run of the Laser Interferometer Gravitational-Wave Observatory. It searches gravitational-wave frequencies from 100 to 300 Hz and covers a wide range of first and second frequency derivatives appropriate for the age of the remnant and for different spin-down mechanisms. No gravitational-wave signal was detected. Within the range of search frequencies, we set 95% confidence upper limits of (0.7-1.2) × 10 -24 on the intrinsic gravitational-wave strain, (0.4-4) …
Ultra-Compact Dwarfs In The Core Of The Coma Cluster, Juan P. Madrid, Alister W. Graham, William E. Harris, Paul Goudfrooij, Duncan A. Forbes, David Carter, John P. Blakeslee, Lee R. Spitler, Henry C. Ferguson
Ultra-Compact Dwarfs In The Core Of The Coma Cluster, Juan P. Madrid, Alister W. Graham, William E. Harris, Paul Goudfrooij, Duncan A. Forbes, David Carter, John P. Blakeslee, Lee R. Spitler, Henry C. Ferguson
Physics and Astronomy Faculty Publications and Presentations
We have discovered both a red and a blue subpopulation of ultra-compact dwarf (UCD) galaxy candidates in the Coma galaxy cluster. We analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera for Surveys Wide Field Channel as part of the Coma Cluster Treasury Survey and have fitted the light profiles of similar to 5000 point-like sources in the vicinity of NGC 4874, one of the two central dominant galaxies of the Coma Cluster. Although almost all of these sources are globular clusters that remain unresolved, we found that 52 objects have effective …
Detecting Massive Gravitons Using Pulsar Timing Arrays, Kejia Lee, F. A. Jenet, Richard H. Price, Norbert Wex, Michael Kramer
Detecting Massive Gravitons Using Pulsar Timing Arrays, Kejia Lee, F. A. Jenet, Richard H. Price, Norbert Wex, Michael Kramer
Physics and Astronomy Faculty Publications and Presentations
At the limit of weak static fields, general relativity becomes Newtonian gravity with a potential field that falls off as inverse distance rather than a theory of Yukawa-type fields with a finite range. General relativity also predicts that the speed of disturbances of its waves is c, the vacuum light speed, and is non-dispersive. For these reasons, the graviton, the boson for general relativity, can be considered to be massless. Massive gravitons, however, are features of some alternatives to general relativity. This has motivated experiments and observations that, so far, have been consistent with the zero-mass graviton of general relativity, …
Dissipation Scales And Anomalous Sinks In Steady Two-Dimensional Turbulence, Eleftherios Gkioulekas
Dissipation Scales And Anomalous Sinks In Steady Two-Dimensional Turbulence, Eleftherios Gkioulekas
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
In previous papers I have argued that the fusion rules hypothesis, which was originally introduced by L’vov and Procaccia in the context of the problem of three-dimensional turbulence, can be used to gain a deeper insight in understanding the enstrophy cascade and inverse energy cascade of two-dimensional turbulence. In the present paper, we show that the fusion rules hypothesis, combined with nonperturbative locality, itself a consequence of the fusion rules hypothesis, dictates the location of the boundary separating the inertial range from the dissipation range. In so doing, the hypothesis that there may be an anomalous enstrophy sink …
Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal
Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Symbioses between microbes and animals are ubiquitous, yet little is known about the intricate mechanisms maintaining such associations. In an emerging mutualistic model system, insect-pathogenic bacteria Photorhabdus and their insect-parasitic nematode partner Heterorhabditis, we found that the bacteria undergo major transcriptional reshaping in the nematode intestine. Besides general starvation mechanisms, the bacteria induce cellular acidification to slow down growth, switch to pentose phosphate pathway to overcome oxidative stress and nutrition limitation, and shed motility but develop biofilm to persist in the nematode intestine until being released into the insect hemolymph. These findings demonstrate how the symbiotic bacteria reduce their …
The Sensitivity Of The Parkes Pulsar Timing Array To Individual Sources Of Gravitational Waves, D. R.B. Yardley, G. B. Hobbs, F. A. Jenet, J. P.W. Verbiest, Z. L. Wen, R. N. Manchester, W. A. Coles, W. Van Straten, M. Bailes, N. D.R. Bhat, S. Burke-Spolaor, D. J. Champion, A. W. Hotan, J. M. Sarkissian
The Sensitivity Of The Parkes Pulsar Timing Array To Individual Sources Of Gravitational Waves, D. R.B. Yardley, G. B. Hobbs, F. A. Jenet, J. P.W. Verbiest, Z. L. Wen, R. N. Manchester, W. A. Coles, W. Van Straten, M. Bailes, N. D.R. Bhat, S. Burke-Spolaor, D. J. Champion, A. W. Hotan, J. M. Sarkissian
Physics and Astronomy Faculty Publications and Presentations
We present the sensitivity of the Parkes Pulsar Timing Array to gravitational waves (GWs) emitted by individual supermassive black hole binary systems in the early phases of coalescing at the cores of merged galaxies. Our analysis includes a detailed study of the effects of fitting a pulsar timing model to non-white timing residuals. Pulsar timing is sensitive at nanoHertz frequencies and hence complementary to Laser Interferometer Gravitational-Wave Observatory and Laser Interferometer Space Antenna. We place a sky-averaged constraint on the merger rate of nearby (z < 0.6) black hole binaries in the early phases of coalescence with a chirp mass of 1010 M⊙ of less than one merger every 7 yr. The prospects for future GW astronomy of this type with the proposed Square Kilometre Array telescope are discussed. © 2010 The Authors. Journal compilation © 2010 RAS.
Compact Binaries In Star Clusters - I. Black Hole Binaries Inside Globular Clusters, J. M.B. Downing, M. J. Benacquista, M. Giersz, R. Spurzem
Compact Binaries In Star Clusters - I. Black Hole Binaries Inside Globular Clusters, J. M.B. Downing, M. J. Benacquista, M. Giersz, R. Spurzem
Physics and Astronomy Faculty Publications and Presentations
We study the compact binary population in star clusters, focusing on binaries containing black holes, using a self-consistent Monte Carlo treatment of dynamics and full stellar evolution. We find that the black holes experience strong mass segregation and become centrally concentrated. In the core the black holes interact strongly with each other and black hole-black hole binaries are formed very efficiently. The strong interactions, however, also destroy or eject the black hole-black hole binaries. We find no black hole-black hole mergers within our simulations but produce many hard escapers that will merge in the Galactic field within a Hubble time. …
Apo B100 Similarities To Viral Proteins Suggest Basis For Ldl-Dna Binding And Transfection Capacity, Juan Guevara, Nagindra Prashad, Boris Ermolinsky, John W. Gaubatz, Dongcheul Kang, Andrea E. Schwarzbach, David S. Loose, Natalia Valentinova Guevara
Apo B100 Similarities To Viral Proteins Suggest Basis For Ldl-Dna Binding And Transfection Capacity, Juan Guevara, Nagindra Prashad, Boris Ermolinsky, John W. Gaubatz, Dongcheul Kang, Andrea E. Schwarzbach, David S. Loose, Natalia Valentinova Guevara
Physics and Astronomy Faculty Publications and Presentations
LDL mediates transfection with plasmid DNA in a variety of cell types in vitro and in several tissues in vivo in the rat. The transfection capacity of LDL is based on apo B100, as arginine/lysine clusters, suggestive of nucleic acid-binding domains and nuclear localization signal sequences, are present throughout the molecule. Apo E may also contribute to this capacity because of its similarity to the Dengue virus capsid proteins and its ability to bind DNA. Synthetic peptides representing two apo B100 regions with prominent Arg/Lys clusters were shown to bind DNA. Region 1 (0014Lys-Ser 0160) shares sequence motifs present in …
An Effective Microwave-Induced Iodine-Catalyzed Method For The Synthesis Of Quinoxalines Via Condensation Of 12-Diamines With 12-Dicarbonyl Compounds, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Robert R. Rodriguez, Bimal K. Banik
An Effective Microwave-Induced Iodine-Catalyzed Method For The Synthesis Of Quinoxalines Via Condensation Of 12-Diamines With 12-Dicarbonyl Compounds, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Robert R. Rodriguez, Bimal K. Banik
Chemistry Faculty Publications and Presentations
A microwave-induced iodine-catalyzed simple, rapid and convenient synthesis of different types of quinoxalines via condensation of 1,2-diamines with 1,2-dicarbonyl compounds has been accomplished with an excellent yield.
An Exploratory Study Of Methicillin-Resistant Staphylococcus Aureus And Sccmec Elements Obtained From A Community Setting Along The Texas Border With Mexico, David R. Ammons, Raghuveer Puttagunta, Jose C. Granados, Georgina De La Garza, George Eyambe, Joanne Rampersad-Ammons
An Exploratory Study Of Methicillin-Resistant Staphylococcus Aureus And Sccmec Elements Obtained From A Community Setting Along The Texas Border With Mexico, David R. Ammons, Raghuveer Puttagunta, Jose C. Granados, Georgina De La Garza, George Eyambe, Joanne Rampersad-Ammons
Chemistry Faculty Publications and Presentations
An exploratory study of methicillin-resistant Staphylococcus aureus (MRSA) and SCCmec elements in bacteria along the Mexican border of south Texas was performed. Between September and December of 2008, 375 swabs of anterior nares were self-collected by students attending the University of Texas-Pan American (UTPA) and cultured for MRSA. Fifty seven bacterial isolates were kept for further analysis that included suspected MRSA and other SCCmec-containing bacteria. Isolates were examined for the presence of nuc, mecA, lukS-PV, and spa genes using PCR. SCCmec and spa typing were also performed. Seven S. aureus isolates were found …
Bifurcations Of Traveling Wave Solutions For An Integrable Equation, Jibin Li, Zhijun Qiao
Bifurcations Of Traveling Wave Solutions For An Integrable Equation, Jibin Li, Zhijun Qiao
School of Mathematical and Statistical Sciences Faculty Publications and Presentations
This paper deals with the following equation mt= 1/2 1/mk xxx− 1/2 1/mk x, which is proposed by Z. J. Qiao J. Math. Phys. 48, 082701 2007 and Qiao and Liu Chaos, Solitons Fractals 41, 587 2009. By adopting the phase analysis method of planar dynamical systems and the theory of the singular traveling wave systems to the traveling wave solutions of the equation, it is shown that for different k, the equation may have infinitely many solitary wave solutions, periodic wave solutions, kink/antikink wave solutions, cusped solitary wave solutions, and breaking loop solutions. We discuss in a detail the …
An Expeditious Synthesis Of N-Substituted Pyrroles Via Microwave-Induced Iodine-Catalyzed Reactions Under Solventless Conditions, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Bimal K. Banik
An Expeditious Synthesis Of N-Substituted Pyrroles Via Microwave-Induced Iodine-Catalyzed Reactions Under Solventless Conditions, Debasish Bandyopadhyay, Sanghamitra Mukherjee, Bimal K. Banik
Chemistry Faculty Publications and Presentations
An expeditious synthesis of N-substituted pyrroles has been developed by reacting 2,5-dimethoxy tetrahydrofuran and several amines using a microwave-induced molecular iodine-catalyzed reaction under solventless conditions.
Nuclear Quantum Effects In The Structure And Lineshapes Of The N2 Near-Edge X-Ray Absorption Fine Structure Spectrum, Shervin Fatehi, Craig P. Schwartz, Richard J. Saykally, David Prendergast
Nuclear Quantum Effects In The Structure And Lineshapes Of The N2 Near-Edge X-Ray Absorption Fine Structure Spectrum, Shervin Fatehi, Craig P. Schwartz, Richard J. Saykally, David Prendergast
Chemistry Faculty Publications and Presentations
We study the relative ability of several models of x-ray absorption spectra to capture the Franck–Condon structure apparent from an experiment on gaseous nitrogen. In doing so, we adopt the Born–Oppenheimer approximation and a constrained density functional theory method for computing the energies of the x-ray-excited molecule. Starting from an otherwise classical model for the spectrum, we systematically introduce more realistic physics, first by substituting the quantum mechanical nuclear radial density in the bond separation R for the classical radial density, then by adding the effect of zero-point energy and other level shifts, and finally by including explicit rovibrational quantization …
Microscopic And Spectroscopic Studies Of Thermally Enhanced Electrospun Pmma Micro- And Nanofibers, Sean Pelfrey, Travis Cantu, Michael R. Papantonakis, Duane L. Simonson, R. Andrew Mcgill, Javier Macossay-Torres
Microscopic And Spectroscopic Studies Of Thermally Enhanced Electrospun Pmma Micro- And Nanofibers, Sean Pelfrey, Travis Cantu, Michael R. Papantonakis, Duane L. Simonson, R. Andrew Mcgill, Javier Macossay-Torres
Chemistry Faculty Publications and Presentations
Carbon nanofibers (CNFs) have been incorporated into poly(methyl methacrylate) (PMMA) through electrospinning. The resulting micro- and nanofibers have been characterized by Scanning Electron Microscopy (SEM), which confirmed fiber formation and demonstrated a core-sheath structure of the PMMA fibers. Thermogravimetric Analysis (TGA) was used to obtain the thermal properties of the materials, indicating an enhancement in the thermal properties of the composite fibers. In addition, Fourier Transform Infrared Spectroscopy (FTIR) was utilized to investigate the interactions of PMMA micro- and nanofibers with CNFs, demonstrating the preferred sites of intermolecular interactions between the polymer matrix and the filler.
On The Anomalous Balmer Line Strengths In Globular Clusters, Violet Poole, Guy Worthey, Hyun Chul Lee, Jedidiah Serven
On The Anomalous Balmer Line Strengths In Globular Clusters, Violet Poole, Guy Worthey, Hyun Chul Lee, Jedidiah Serven
Physics and Astronomy Faculty Publications and Presentations
Spectral feature index diagrams with integrated globular clusters and simple stellar population models often show that some clusters have weak Hβ, so weak that even the oldest models cannot match the observed feature depths. In this work, we rule out the possibility that abundance mixture effects are responsible for the weak indices unless such changes operate to cool the entire isochrone. We discuss this result in the context of other explanations, including horizontal branch morphology, blue straggler populations, and nebular or stellar emission fill-in, finding a preference for flaring in M giants as an explanation for the Hβ anomaly. © …
Remarkable Iodine-Catalyzed Synthesis Of Novel Pyrrole- Bearing N-Polyaromatic B-Lactams, Debasish Bandyopadhyay, Gildardo Rivera, Isabel Salinas, Hector Aguilar, Bimal K. Banik
Remarkable Iodine-Catalyzed Synthesis Of Novel Pyrrole- Bearing N-Polyaromatic B-Lactams, Debasish Bandyopadhyay, Gildardo Rivera, Isabel Salinas, Hector Aguilar, Bimal K. Banik
Chemistry Faculty Publications and Presentations
Because of their interesting biological properties various methods for the synthesis of substituted pyrroles are described in the literature. However, synthesis of pyrroles fused with a β-lactam ring has not been reported. Our group has demonstrated synthesis and biological evaluation of various β-lactams as anticancer agents. The anticancer activities of these compounds have prompted us to study the synthesis of pyrroles bound to the β-lactams. We have identified an expeditious synthetic method for the preparation of pyrroles fused with β-lactams by reacting 3-amino β-lactams with acetonylacetone in the presence of catalytic amounts (5 mol%) of molecular iodine at room temperature. …
Shape Replication Through Self-Assembly And Rnase Enzymes, Zachary Abel, Nadia Benbernou, Mirela Damian, Erik D. Demaine, Martin L. Demaine, Robin Flatland, Scott D. Kominers, Robert Schweller
Shape Replication Through Self-Assembly And Rnase Enzymes, Zachary Abel, Nadia Benbernou, Mirela Damian, Erik D. Demaine, Martin L. Demaine, Robin Flatland, Scott D. Kominers, Robert Schweller
Computer Science Faculty Publications and Presentations
We introduce the problem of shape replication in the Wang tile self-assembly model. Given an input shape, we consider the problem of designing a self-assembly system which will replicate that shape into either a specific number of copies, or an unbounded number of copies. Motivated by practical DNA implementations of Wang tiles, we consider a model in which tiles consisting of DNA or RNA can be dynamically added in a sequence of stages. We further permit the addition of RNase enzymes capable of disintegrating RNA tiles. Under this model, we show that arbitrary genus-0 shapes can be replicated infinitely many …
Unidirectional Nonlinear Pt-Symmetric Optical Structures, Hamidreza Ramezani, Tsampikos Kottos
Unidirectional Nonlinear Pt-Symmetric Optical Structures, Hamidreza Ramezani, Tsampikos Kottos
Physics and Astronomy Faculty Publications and Presentations
We show that nonlinear optical structures involving a balanced gain-loss profile can act as unidirectional optical valves. This is made possible by exploiting the interplay between the fundamental symmetries of parity (P) and time (T), with optical nonlinear effects. This unidirectional dynamics is specifically demonstrated for the case of an integrable PT-symmetric nonlinear system.
Searches For Gravitational Waves From Known Pulsars With Science Run 5 Ligo Data, B. P. Abbott, R. Abbott, F. Acernese, R. Adhikari, P. Ajith, B. Allen, G. Allen, M. Alshourbagy, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, H. Armandula, P. Armor, K. G. Arun, Y. Aso, S. Aston, P. Astone, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, C. Barker, D. Barker, F. Barone
Searches For Gravitational Waves From Known Pulsars With Science Run 5 Ligo Data, B. P. Abbott, R. Abbott, F. Acernese, R. Adhikari, P. Ajith, B. Allen, G. Allen, M. Alshourbagy, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, H. Armandula, P. Armor, K. G. Arun, Y. Aso, S. Aston, P. Astone, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, C. Barker, D. Barker, F. Barone
Physics and Astronomy Faculty Publications and Presentations
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 …
Particle Swarm Optimization And Gravitational Wave Data Analysis: Performance On A Binary Inspiral Testbed, Yan Wang, Soumya Mohanty
Particle Swarm Optimization And Gravitational Wave Data Analysis: Performance On A Binary Inspiral Testbed, Yan Wang, Soumya Mohanty
Physics and Astronomy Faculty Publications and Presentations
The detection and estimation of gravitational wave signals belonging to a parameterized family of waveforms requires, in general, the numerical maximization of a data-dependent function of the signal parameters. Because of noise in the data, the function to be maximized is often highly multimodal with numerous local maxima. Searching for the global maximum then becomes computationally expensive, which in turn can limit the scientific scope of the search. Stochastic optimization is one possible approach to reducing computational costs in such applications. We report results from a first investigation of the particle swarm optimization method in this context. The method is …
All-Sky Search For Gravitational-Wave Bursts In The First Joint Ligo-Geo-Virgo Run, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, R. Grosso, Soumya Mohanty, S. Mukherjee, Malik Rakhmanov, Joseph D. Romano, Robert Stone
All-Sky Search For Gravitational-Wave Bursts In The First Joint Ligo-Geo-Virgo Run, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, R. Grosso, Soumya Mohanty, S. Mukherjee, Malik Rakhmanov, Joseph D. Romano, Robert Stone
Physics and Astronomy Faculty Publications and Presentations
We present results from an all-sky search for unmodeled gravitational-wave bursts in the data collected by the LIGO, GEO 600 and Virgo detectors between November 2006 and October 2007. The search is performed by three different analysis algorithms over the frequency band 50–6000 Hz. Data are analyzed for times with at least two of the four LIGO-Virgo detectors in coincident operation, with a total live time of 266 days. No events produced by the search algorithms survive the selection cuts. We set a frequentist upper limit on the rate of gravitational-wave bursts impinging on our network of detectors. When combined …
A Quadratic Lower Bound For Rocchio’S Similarity-Based Relevance Feedback Algorithm With A Fixed Query Updating Factor, Zhixiang Chen, Bin Fu, John P. Abraham
A Quadratic Lower Bound For Rocchio’S Similarity-Based Relevance Feedback Algorithm With A Fixed Query Updating Factor, Zhixiang Chen, Bin Fu, John P. Abraham
Computer Science Faculty Publications and Presentations
Rocchio’s similarity-based relevance feedback algorithm, one of the most important query reformation methods in information retrieval, is essentially an adaptive supervised learning algorithm from examples. In practice, Rocchio’s algorithm often uses a fixed query updating factor. When this is the case, we strengthen the linear Ω(n) lower bound obtained by Chen and Zhu (Inf. Retr. 5:61–86, 2002) and prove that Rocchio’s algorithm makes Ω(k(n−k)) mistakes in searching for a collection of documents represented by a monotone disjunction of k relevant features over the n-dimensional binary vector space {0,1}n, …
The Lisa Gravitational Wave Foreground: A Study Of Double White Dwarfs, Ashley J. Ruiter, Krzysztof Belczynski, Matthew Benacquista, Shane L. Larson, Gabriel Williams
The Lisa Gravitational Wave Foreground: A Study Of Double White Dwarfs, Ashley J. Ruiter, Krzysztof Belczynski, Matthew Benacquista, Shane L. Larson, Gabriel Williams
Physics and Astronomy Faculty Publications and Presentations
Double white dwarfs (WDs) are expected to be a source of confusion-limited noise for the future gravitational wave observatory LISA. In a specific frequency range, this \"foreground noise\" is predicted to rise above the instrumental noise and hinder the detection of other types of signals, e.g., gravitational waves arising from stellar-mass objects inspiraling into massive black holes. In many previous studies, only detached populations of compact object binaries have been considered in estimating the LISA gravitational wave foreground signal. Here, we investigate the influence of compact object detached and Roche-Lobe overflow (RLOF) Galactic binaries on the shape and strength of …
Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, R. Grosso, J. Li, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano, Robert Stone, B. Vaishnav
Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, R. Grosso, J. Li, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano, Robert Stone, B. Vaishnav
Physics and Astronomy Faculty Publications and Presentations
We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-Wave Observatory and Virgo detectors. Five months of data were collected during the Laser Interferometer Gravitational-Wave Observatory’s S5 and Virgo’s VSR1 science runs. The search focused on signals from binary mergers with a total mass between 2 and 35M⊙. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for nonspinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7×10−3 yr−1 L−110, 2.2×10−3 yr−1 L−110, …
Search For Gravitational-Wave Inspiral Signals Associated With Short Gamma-Ray Bursts During Ligo's Fifth And Virgo's First Science Run, J. Abadie, B. P. Abbott, R. Abbott, T. Accadia, F. Acernese, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, K. G. Arun, Y. Aso, S. Aston, P. Astone, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, F. Barone, B. Barr
Search For Gravitational-Wave Inspiral Signals Associated With Short Gamma-Ray Bursts During Ligo's Fifth And Virgo's First Science Run, J. Abadie, B. P. Abbott, R. Abbott, T. Accadia, F. Acernese, R. Adhikari, P. Ajith, B. Allen, G. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, K. G. Arun, Y. Aso, S. Aston, P. Astone, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, F. Barone, B. Barr
Physics and Astronomy Faculty Publications and Presentations
Progenitor scenarios for short gamma-ray bursts (short GRBs) include coalescenses of two neutron stars or a neutron star and black hole, which would necessarily be accompanied by the emission of strong gravitational waves. We present a search for these known gravitational-wave signatures in temporal and directional coincidence with 22 GRBs that had sufficient gravitational-wave data available in multiple instruments during LIGO's fifth science run, S5, and Virgo's first science run, VSR1. We find no statistically significant gravitational-wave candidates within a [ - 5, + 1)s window around the trigger time of any GRB. Using the Wilcoxon-Mann-Whitney U-test, we find no …