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System Design And Optimization Of Optical Coherence Tomography, Avni Ceyhun Akcay Jan 2005

System Design And Optimization Of Optical Coherence Tomography, Avni Ceyhun Akcay

Electronic Theses and Dissertations

Optical coherence imaging, including tomography (OCT) and microscopy (OCM), has been a growing research field in biomedical optical imaging in the last decade. In this imaging modality, a broadband light source, thus of short temporal coherence length, is used to perform imaging via interferometry. A challenge in optical coherence imaging, as in any imaging system towards biomedical diagnosis, is the quantification of image quality and optimization of the system components, both a primary focus of this research. We concentrated our efforts on the optimization of the imaging system from two main standpoints: axial point spread function (PSF) and practical steps …

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Interferometry-Based Free Space Communication And Information Processing, Muzamil Arshad Arain Jan 2005

Interferometry-Based Free Space Communication And Information Processing, Muzamil Arshad Arain

Electronic Theses and Dissertations

This dissertation studies, analyzes, and experimentally demonstrates the innovative use of interference phenomenon in the field of opto-electronic information processing and optical communications. A number of optical systems using interferometric techniques both in the optical and the electronic domains has been demonstrated in the filed of signal transmission and processing, optical metrology, defense, and physical sensors. Specifically it has been shown that the interference of waves in the form of holography can be exploited to realize a novel optical scanner called Code Multiplexed Optical Scanner (C-MOS). The C-MOS features large aperture, wide scan angles, 3-D beam control, no moving parts, …

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High Gain / Broadband Oxide Glasses For Next Generation Raman Amplifiers, Clara Rivero Jan 2005

High Gain / Broadband Oxide Glasses For Next Generation Raman Amplifiers, Clara Rivero

Electronic Theses and Dissertations

Interest in Raman amplification has undergone a revival due to the rapidly increasing bandwidth requirements for communications transmission, both for long haul and local area networks, and recent developments in the telecom fiber industry and diode laser technology. In contrast to rare earth doped fiber amplifiers, for which the range of wavelengths is fixed and limited, Raman gain bandwidths are larger and the operating wavelength is fixed only by the pump wavelength and the bandwidth of the Raman active medium. In this context, glasses are the material of choice for this application due to their relatively broad spectral response, and …

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A Survey For Planetary Transits In The Field Of Ngc 7789, D. M. Bramich, Keith Horne, I. A. Bond, R. A. Street, A. Collier Cameron, B. Hood, J. Cooke, D. James, T. A. Lister, David Mitchell, K. Pearson, A. Penny, A. Quirrenbach, N. Safizadeh, Y. Tsapras Jan 2005

A Survey For Planetary Transits In The Field Of Ngc 7789, D. M. Bramich, Keith Horne, I. A. Bond, R. A. Street, A. Collier Cameron, B. Hood, J. Cooke, D. James, T. A. Lister, David Mitchell, K. Pearson, A. Penny, A. Quirrenbach, N. Safizadeh, Y. Tsapras

Physics

We present results from 30 nights of observations of the open cluster NGC 7789 with the Wide Field Camera on the Isaac Newton Telescope, La Palma. From ∼900 epochs, we obtained light curves and Sloan r'− i' colours for ∼33000 stars, with ∼2400 stars having better than 1 percent precision. We expected to detect ∼2 transiting hot Jupiter planets if 1 percent of stars host such a companion and a typical hot Jupiter radius is ∼1.2 RJ. We find 24 transit candidates, 14 of which we can assign a period. We rule out the transiting planet model …

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Epr And X-Ray Crystallographic Characterization Of The Product-Bound Form Of The MnIi-Loaded Methionyl Aminopeptidase From Pyrococcus Furiosus, Alicja J. Copik, Boguslaw P. Nocek, Sabina I. Swierczek, Shane Ruebush, Se Bok Jang, Lu Meng, Ventris M. D'Souza, John W. Peters, Brian Bennett, Richard C. Holz Jan 2005

Epr And X-Ray Crystallographic Characterization Of The Product-Bound Form Of The MnIi-Loaded Methionyl Aminopeptidase From Pyrococcus Furiosus, Alicja J. Copik, Boguslaw P. Nocek, Sabina I. Swierczek, Shane Ruebush, Se Bok Jang, Lu Meng, Ventris M. D'Souza, John W. Peters, Brian Bennett, Richard C. Holz

Physics Faculty Research and Publications

Methionine aminopeptidases (MetAPs) are ubiquitous metallohydrolases that remove the N-terminal methionine from nascent polypeptide chains. Although various crystal structures of MetAP in the presence of inhibitors have been solved, the structural aspects of the product-bound step has received little attention. Both perpendicular- and parallel-mode electron paramagnetic resonance (EPR) spectra were recorded for the MnII-loaded forms of the type-I (Escherichia coli) and type-II (Pyrococcus furiosus) MetAPs in the presence of the reaction product l-methionine (l-Met). In general, similar EPR features were observed for both [MnMn(EcMetAP-I)]−l-Met and [MnMn(PfMetAP-II)]−l-Met. The observed perpendicular-mode EPR …

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Description Of Light Propagation Through A Circular Aperture Using Nonparaxial Vector Diffraction Theory, Glen D. Gillen, Shekhar Guha Jan 2005

Description Of Light Propagation Through A Circular Aperture Using Nonparaxial Vector Diffraction Theory, Glen D. Gillen, Shekhar Guha

Physics

Using nonparaxial vector diffraction theory derived using the Hertz vector formalism, integral expressions for the electric and magnetic field components of light within and beyond an apertured plane are obtained for an incident plane wave. For linearly polarized light incident on a circular aperture, the integrals for the field components and for the Poynting vector are numerically evaluated. By further two-dimensional integration of a Poynting vector component, the total transmission of a circular aperture is determined as a function of the aperture radius to wavelength ratio. The validity of using Kirchhoff boundary conditions in the aperture plane is also examined …

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Charged Higgs Production: Higher-Order Corrections, Nikolaos Kidonakis Jan 2005

Charged Higgs Production: Higher-Order Corrections, Nikolaos Kidonakis

Faculty Articles

I present a calculation of higher-order radiative corrections to charged Higgs production in association with a top quark via the process bg -> tH-. Results for charged Higgs production at the LHC are presented, including the dependence of the cross section on the charged Higgs mass, the top quark mass, the factorization and renormalization scales, and tan beta. I show that the theoretical prediction for the cross section is significantly enhanced and is greatly stabilized when the higher-order corrections are included.

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Nonlinear Optics And An Experimental Test Of Bell’S Inequality, Michael Herbst Jan 2005

Nonlinear Optics And An Experimental Test Of Bell’S Inequality, Michael Herbst

Honors Papers

The purpose of this investigation is to assemble an apparatus capable of testing Bell’s inequality for a local hidden variable. The historical context and theoretical developments that led to this area of inquiry are presented. Expected experimental results stemming from two distinct physical theories are introduced. Procedures are given that outline the assembly of a device capable of testing these theories. Analysis confirming the successful completion of a majority of the steps is presented, and the final necessary steps are detailed. Finally, a laboratory prompt for this experiment’s use in Oberlin College’s advanced laboratory class is given.

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Modernization Of The Hilger And Watts Guage-Block Interferometer, Michael O'Hora, Brian Bowe, Vincent Toal, Sean Peyton Jan 2005

Modernization Of The Hilger And Watts Guage-Block Interferometer, Michael O'Hora, Brian Bowe, Vincent Toal, Sean Peyton

Articles

The Hilger & Watts gauge-block interferometer was designed and manufactured commercially in the 1950s. The instrument uses isotope lamps as wavelength standards to perform absolute length calibration of gauge blocks (slip gauges) up to 100 mm in length, to an accuracy of approximately 1 ppm. It is entirely manually operated. In order to make the instrument more suitable for the modern laboratory, new hardware has been added, and a customized software package developed to automate the measurement process. This paper shows how interferograms may be imaged successfully at each of the eight available wavelengths, and the critical fringe fraction measurement …

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Study Of The Electronic Structure Of Cafeo₃, Jinbo Yang, M. S. Kim, Qingsheng Cai, X.-D. Zhou, Harlan U. Anderson, William Joseph James, William B. Yelon Jan 2005

Study Of The Electronic Structure Of Cafeo₃, Jinbo Yang, M. S. Kim, Qingsheng Cai, X.-D. Zhou, Harlan U. Anderson, William Joseph James, William B. Yelon

Materials Science and Engineering Faculty Research & Creative Works

We have studied the charge disproportionation phenomenon in CaFeO3 using the local-spin density approximation with the on-site Coulomb interaction parameter U and exchange parameter J. The calculation reveals that the total number of the 3d electrons is about 5.1 for both Fe(1)(Fe5+) and Fe(2)(Fe3+) atoms, and that there are about 0.25 electron holes in the O-2p band. Therefore, the charge disproportionation can be more accurately described as 2d5L(Fe4+)=d5L2(Fe5+)+d5(Fe3+), where L denotes a hole in the oxygen 2p band, instead of 2d4(Fe4+)=d3(Fe5+)+d5(Fe3+). The hybridization between the Fe-3d and O-2p orbitals is stronger for Fe(1) than for Fe(2) due to the shorter …

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Inclusive And Exclusive Compton Processes In Quantum Chromodynamics, A. Psaker Jan 2005

Inclusive And Exclusive Compton Processes In Quantum Chromodynamics, A. Psaker

Physics Theses & Dissertations

In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized …

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Structure Property Relationships In Organic Conjugated Systems, Luke O'Neill, Patrick Lynch, Mary Mcnamara Jan 2005

Structure Property Relationships In Organic Conjugated Systems, Luke O'Neill, Patrick Lynch, Mary Mcnamara

Articles

A series of π conjugated oligomers were studied by absorption and photoluminescence spectroscopy. A linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation is further examined using Raman spectroscopy, whereby …

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Coupled Electrical And Magnetic Properties In (La,Sr)Feo3-Δ, X.-D. Zhou, Qingsheng Cai, Jinbo Yang, M. S. Kim, William B. Yelon, William Joseph James, Y.-W. Shin, B. J. Scarfino, Harlan U. Anderson Jan 2005

Coupled Electrical And Magnetic Properties In (La,Sr)Feo3-Δ, X.-D. Zhou, Qingsheng Cai, Jinbo Yang, M. S. Kim, William B. Yelon, William Joseph James, Y.-W. Shin, B. J. Scarfino, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

This article is aimed at studying the temperature dependence oxygen nonstoichiometry, magnetic moments, Fe3+ fraction, Néel temperature and conductivity of (La,Sr)FeO3-δ. It is found that the magnetic properties in La0.60 Sr0.40 Fe3-δ is determined by Fe3+ and its concentration, and the conductance is resulted from Fe4+ ions, which act as electron holes. Both of magnetic and electrical properties were directly governed by oxygen nonstoichiometry (δ). when δ=0.2, the compound has maximum Fe3+, the saturation magnetic moments and Néel temperature are 3.8 µB and 410 °C, both at the highest level, …

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Distorted Wave Born And Three-Body Distorted Wave Born Approximation Calculations Of The Fully Differential Cross Section For Electron-Impact Ionization Of Nitrogen Molecules, Junfang Gao, Don H. Madison, Jerry Peacher Jan 2005

Distorted Wave Born And Three-Body Distorted Wave Born Approximation Calculations Of The Fully Differential Cross Section For Electron-Impact Ionization Of Nitrogen Molecules, Junfang Gao, Don H. Madison, Jerry Peacher

Physics Faculty Research & Creative Works

Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCSs) for low-energy electron-impact ionization of large molecules. We have recently proposed the orientation-averaged molecular orbital (OAMO) for calculating cross sections averaged over molecular orientations. In this paper, we use the OAMO to calculate distorted wave Born approximation (DWBA) and molecular three-body distorted wave (M3DW) Born approximation FDCS for electron-impact ionization of the nitrogen molecule. Both coplanar symmetric and asymmetric FDCSs are investigated in the energy range of 35.6-400 eV. by comparing with the experimental data, we found that the M3DW is reasonably accurate in this energy …

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How Generic Scale Invariance Influences Quantum And Classical Phase Transitions, D. Belitz, T. Kirkpatrick, Thomas Vojta Jan 2005

How Generic Scale Invariance Influences Quantum And Classical Phase Transitions, D. Belitz, T. Kirkpatrick, Thomas Vojta

Physics Faculty Research & Creative Works

This review discusses a paradigm that has become of increasing importance in the theory of quantum phase transitions, namely, the coupling of the order-parameter fluctuations to other soft modes and the resulting impossibility of constructing a simple Landau-Ginzburg-Wilson theory in terms of the order parameter only. The soft modes in question are manifestations of generic scale invariance, i.e., the appearance of long-range order in whole regions in the phase diagram. The concept of generic scale invariance and its influence on critical behavior is explained using various examples, both classical and quantum mechanical. The peculiarities of quantum phase transitions are discussed, …

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Static Pairwise Annihilation In Complex Networks, M. F. Laguna, M. Aldana, H. Larralde, V. M. Kenkre, Paul Ernest Parris Jan 2005

Static Pairwise Annihilation In Complex Networks, M. F. Laguna, M. Aldana, H. Larralde, V. M. Kenkre, Paul Ernest Parris

Physics Faculty Research & Creative Works

We study static annihilation on complex networks, in which pairs of connected particles annihilate at a constant rate during time. Through a mean-field formalism, we compute the temporal evolution of the distribution of surviving sites with an arbitrary number of connections. This general formalism, which is exact for disordered networks, is applied to Kronecker, Erdös-Rényi (i.e., Poisson), and scale-free networks. We compare our theoretical results with extensive numerical simulations obtaining excellent agreement. Although the mean-field approach applies in an exact way neither to ordered lattices nor to small-world networks, it qualitatively describes the annihilation dynamics in such structures. Our results …

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Critical Behavior And Griffiths Effects In The Disordered Contact Process, Thomas Vojta, Mark Dickison Jan 2005

Critical Behavior And Griffiths Effects In The Disordered Contact Process, Thomas Vojta, Mark Dickison

Physics Faculty Research & Creative Works

We study the nonequilibrium phase transition in the one-dimensional contact process with quenched spatial disorder by means of large-scale Monte Carlo simulations for times up to 109 and system sizes up to 107 sites. In agreement with recent predictions of an infinite-randomness fixed point, our simulations demonstrate activated (exponential) dynamical scaling at the critical point. The critical behavior turns out to be universal, even for weak disorder. However, the approach to this asymptotic behavior is extremely slow, with crossover times of the order of 104 or larger. In the Griffiths region between the clean and the dirty critical points, we …

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Precollision And Postcollision Electron-Electron Correlation Effects For Intermediate-Energy Proton-Impact Ionization Of Helium, M. Foster, Jerry Peacher, Michael Schulz, Ahmad Hasan, Don H. Madison Jan 2005

Precollision And Postcollision Electron-Electron Correlation Effects For Intermediate-Energy Proton-Impact Ionization Of Helium, M. Foster, Jerry Peacher, Michael Schulz, Ahmad Hasan, Don H. Madison

Physics Faculty Research & Creative Works

We report fully differential cross sections (FDCS) for the single ionization of helium by a 75 keV incident energy proton. Previous three-body distorted wave (3DW) calculations for this collision system are in poor agreement with the absolute magnitude of the experimental measurements. The 3DW approximation treats the four-body problem as an effective three-body problem in which the passive electron does not participate in the collision. We have developed a full four-body approach in which the passive electron fully participates in the collision. It will be shown that the FDCS is very sensitive to the treatment of the passive electron-ejected electron …

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Quantum Griffiths Effects In Itinerant Heisenberg Magnets, Thomas Vojta, Jörg Schmalian Jan 2005

Quantum Griffiths Effects In Itinerant Heisenberg Magnets, Thomas Vojta, Jörg Schmalian

Physics Faculty Research & Creative Works

We study the influence of quenched disorder on quantum phase transitions in itinerant magnets with Heisenberg spin symmetry, paying particular attention to rare disorder fluctuations. In contrast to the Ising case where the Landau damping of the spin fluctuations suppresses the tunneling of the rare regions, the Heisenberg system displays strong power-law quantum Griffiths singularities in the vicinity of the quantum critical point. We discuss these phenomena based on general scaling arguments, and we illustrate them by an explicit calculation for O(N) spin symmetry in the large-N limit. We also discuss broad implications for the classification of quantum phase transitions …

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Tunable Conductivity And Conduction Mechanism In An Ultraviolet Light Activated Electronic Conductor, Mariana I. Bertoni, Thomas O. Mason, Julia E. Medvedeva, Arthur J. Freeman, Kenneth R. Poeppelmeier, B. Delley Jan 2005

Tunable Conductivity And Conduction Mechanism In An Ultraviolet Light Activated Electronic Conductor, Mariana I. Bertoni, Thomas O. Mason, Julia E. Medvedeva, Arthur J. Freeman, Kenneth R. Poeppelmeier, B. Delley

Physics Faculty Research & Creative Works

A tunable conductivity has been achieved by controllable substitution of an ultraviolet light activated electronic conductor. The transparent conducting oxide system H-doped Ca12-xMgxAl14O33 (x=0,0.1,0.3,0.5,0.8,1.0) presents a conductivity that is strongly dependent on the substitution level and temperature. Four-point dc-conductivity decreases with x from 0.26 S/cm (x=0) to 0.106 S/cm (x=1) at room temperature. At each composition the conductivity increases (reversibly with temperature) until a decomposition temperature is reached; above this value, the conductivity drops dramatically due to hydrogen recombination and loss. The observed conductivity behavior is consistent with the predictions of our first principles density functional calculations for the Mg-substituted …

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Determination Of Cadmium Nitrate Mass Through Neutron Activation Analysis, Charles Williams Jan 2005

Determination Of Cadmium Nitrate Mass Through Neutron Activation Analysis, Charles Williams

Opportunities for Undergraduate Research Experience Program (OURE)

Neutron Activation Analysis is a method of determining the composition of a sample wherein the sample is irradiated, then measured through gamma ray spectroscopy. This method can also be used to determine the mass of a particular substance within an unknown sample by comparing the gamma ray spectroscopy results to that of known results and applying a p redetermined linear relationship between known sample mass (or molarity) and the primary peak area form the gamma ray spectroscopy results. This relationship is what our project set out to determine for differing concentrations in a standard volume of Cadmium Nitrate solution (CdNO …

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Making Sense Of Nanocrystal Lattice Fringes, P. Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell Jan 2005

Making Sense Of Nanocrystal Lattice Fringes, P. Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell

Physics Faculty Publications and Presentations

The orientation dependence of thin-crystal lattice fringes can be gracefully quantified using fringe-visibility maps, a direct-space analog of Kikuchi maps [Nishikawa and Kikuchi, Nature (London) 121, 1019 (1928)]. As in navigation of reciprocal space with the aid of Kikuchi lines, fringe-visibility maps facilitate acquisition of crystallographic information from lattice images. In particular, these maps can help researchers to determine the three-dimensional lattice of individual nanocrystals, to 'fringe-fingerprint' collections of randomly oriented particles, and to measure local specimen thickness with only a modest tilt. Since the number of fringes in an image increases with maximum spatial-frequency squared, these strategies (with help …

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Investigation Of The Mechanism Of Polarization Switching In Ferroelectric Capacitors By Three-Dimensional Piezoresponse Force Microscopy, Brian J. Rodriguez, Alexei Gruverman, Angus I. Kingon, Robert J. Nemanich, J. S. Cross Jan 2005

Investigation Of The Mechanism Of Polarization Switching In Ferroelectric Capacitors By Three-Dimensional Piezoresponse Force Microscopy, Brian J. Rodriguez, Alexei Gruverman, Angus I. Kingon, Robert J. Nemanich, J. S. Cross

Alexei Gruverman Publications

A mechanism for the switching behavior of (111)-oriented Pb(Zr, Ti)O3-based 1 × 1.5 μm2 capacitors has been investigated using three-dimensional piezoresponse force microscopy (3D-PFM). A combination of vertical and lateral piezoresponse force microscopy (VPFM and LPFM) has been used to map the out-of-plane and the in-plane components of the polarization. The three-dimensional polarization distribution was reconstructed by quantitative analysis of the PFM amplitude images of poled PZT capacitors while taking into account contrast variations in the PFM phase images. The switching behavior of the capacitors was determined by comparison of the static domain patterns in the same …

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Einstein’S Impact On Optics At The Frontier, Donald Umstadter Jan 2005

Einstein’S Impact On Optics At The Frontier, Donald Umstadter

Donald Umstadter Publications

The seminal contributions made by Einstein a century ago have enabled a new frontier area of science, called high-field science. This research involves the physics of the interactions of matter with electromagnetic fields at its highest levels ever achieved in the laboratory. Besides being of fundamental importance to physics research, the discoveries being made in this area are also leading to a new generation of compact and ultrashort-duration particle accelerators and X-ray light sources, with applications ranging from nuclear fusion to cancer therapy.

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Dynamics Of Filament Formation In A Kerr Medium (With Erratum), Martin Centurion, Ye Pu, Mankei Tsang, Demetri Psaltis Jan 2005

Dynamics Of Filament Formation In A Kerr Medium (With Erratum), Martin Centurion, Ye Pu, Mankei Tsang, Demetri Psaltis

Martin Centurion Publications

We have studied the large-scale beam breakup and filamentation of femtosecond pulses in a Kerr medium. We have experimentally monitored the formation of stable light filaments, conical emission, and interactions between filaments. Three major stages lead to the formation of stable light filaments: First the beam breaks up into a pattern of connected lines (constellation), then filaments form on the constellations, and finally the filaments release a fraction of their energy through conical emission. We observed a phase transition to a faster filamentation rate at the onset of conical emission. We attribute this to the interaction of conical emissions with …

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Standard Ubv Observations At The Çanakkale University Observatory (Çuo), Hi̇cran Bakiş, Volkan Bakiş, Osman Demi̇rcan, Edwin Budding Jan 2005

Standard Ubv Observations At The Çanakkale University Observatory (Çuo), Hi̇cran Bakiş, Volkan Bakiş, Osman Demi̇rcan, Edwin Budding

Turkish Journal of Physics

By using standard and comparison star observations carried out at different times of the year, at Çanakkale Onsekiz Mart University Observatory, we obtained the atmospheric extinction coefficients at the observatory. We also obtained transformation coefficients and zero-point constants for the transformation to the standard Johnson UBV system, of observations in the local system carried out with the SSP5A photometer and T40 telescope. The transmission curves and the mean wavelengths of the UBV filters as measured in the laboratory appear not much different from those of the standard Johnson system and found inside the transmission curve of the standard mean atmosphere.

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Afm And C-Afm Studies Of Gan Films, Katherine Cooper Jan 2005

Afm And C-Afm Studies Of Gan Films, Katherine Cooper

Theses and Dissertations

This thesis uses the techniques of atomic force microscope (AFM) and conductive AFM (C-AFM) to study the conduction properties of n-type GaN films. A total of 16 samples were examined and grouped according to their surface morphologies and conduction behaviors. The most common type of surface morpliology was that of Ga-rich samples having undulating "hillocks" with interspersed holes. Although most of the samples had this common morphology, their local conduction behaviors were not all similar. Local I-V spectra of the tip-sample Schottky contact could be grouped according to three major types: low leakage, high leakage, and "p-type". The highest quality …

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Search For Gravitational Waves From Primordial Black Hole Binary Coalescences In The Galactic Halo, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres Jan 2005

Search For Gravitational Waves From Primordial Black Hole Binary Coalescences In The Galactic Halo, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole binary coalescence with component masses in the range 0.2–1.0M⊙. The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing nonspinning black holes with masses in the range 0.2–1.0M⊙, we place an observational upper limit on the rate of primordial black hole coalescence of 63 per year …

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Upper Limits On A Stochastic Background Of Gravitational Waves, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres Jan 2005

Upper Limits On A Stochastic Background Of Gravitational Waves, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of Ω0

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Limits On Gravitational-Wave Emission From Selected Pulsars Using Ligo Data, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres Jan 2005

Limits On Gravitational-Wave Emission From Selected Pulsars Using Ligo Data, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics & Astronomy Faculty Publications

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10−24. These strain limits translate into limits on the equatorial ellipticities of the pulsars, …

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