Results for "Oliver L. White"

total 105281took 0.13s
Discrete ambiguities in the determination of the CP anglesOct 26 2000Oct 27 2000We review briefly the problem of the discrete ambiguities in the determination of the CKM angles, by classifying them into different categories. We then focus on cos(2beta) and the extraction of alpha using QCD factorization.
Grand Unification, Gravitational Waves, and the Cosmic Microwave Background AnisotropyMay 08 1992We re-examine the gravitational wave background resulting from inflation and its effect on the cosmic microwave background radiation. The new COBE measurement of a cosmic background quadrupole anisotropy places an upper limit on the vacuum energy during ... More
Propagation of nonadiabatic magnetoacoustic waves in a threaded prominence with mass flowsSep 29 2008High resolution observations of solar filaments suggest the presence of groups of prominence threads, i.e. the fine-structures of prominences, which oscillate coherently (in phase). In addition, mass flows along threads have been often observed. Here, ... More
Spatial Damping of Propagating Kink Waves in Prominence ThreadsSep 24 2010Transverse oscillations and propagating waves are frequently observed in threads of solar prominences/filaments and have been interpreted as kink magnetohydrodynamic (MHD) modes. We investigate the spatial damping of propagating kink MHD waves in transversely ... More
Leptogenesis within a generalized quark-lepton symmetryAug 15 2007Oct 26 2007Quark-lepton symmetry has been shown to be inconsistent with baryogenesis via leptogenesis in natural schemes of the see-saw mechanism. Within the phenomenological approach of textures, we relax this strict symmetry and propose weaker conditions, namely ... More
Oscillatory Modes of a Prominence-PCTR-Corona Slab ModelOct 16 2007Oscillations of magnetic structures in the solar corona have often been interpreted in terms of magnetohydrodynamic waves. We study the adiabatic magnetoacoustic modes of a prominence plasma slab with a uniform longitudinal magnetic field, surrounded ... More
Non-Minimal Supersymmetric Higgs Bosons at LEP2Aug 22 1995Nov 10 1995We discuss the discovery reach of LEP2 for the Higgs sector of a general extension of the MSSM including a single gauge singlet field. This change introduces a new quartic Higgs boson self-coupling which can increase the masses of the CP-even states, ... More
Resolving the Constrained Minimal and Next-to-Minimal Supersymmetric Standard ModelsMay 17 1995Oct 06 1995We perform a detailed analysis of the next-to-minimal supersymmetric standard model (NMSSM), imposing the constraints of two-loop gauge coupling unification, universal soft supersymmetry breaking and the correct pattern of electroweak symmetry breaking. ... More
Resonantly Damped Kink Magnetohydrodynamic Waves in a Partially Ionized Filament ThreadSep 19 2009Transverse oscillations of solar filament and prominence threads have been frequently reported. These oscillations have the common features of being of short period (2-10 min) and being damped after a few periods. Kink magnetohydrodynamic (MHD) wave modes ... More
Attenuation of small-amplitude oscillations in a prominence-corona model with a transverse magnetic fieldJan 24 2008Aug 14 2008Small-amplitude prominence oscillations are usually damped after a few periods. We study the attenuation of non-adiabatic magnetoacoustic waves in a slab prominence embedded in the coronal medium. We assume an equilibrium configuration with a transverse ... More
Reshaping the use of digital tools to fight malariaMay 06 2018In this extended abstract we present our approach to marshal digital tools in the fight against malaria. We describe our scalable infrastructure which leverages abstractions to support effective deployment of existing computational models and their associated ... More
Non-adiabatic magnetohydrodynamic waves in a cylindrical prominence thread with mass flowMar 18 2008May 21 2008High-resolution observations show that oscillations and waves in prominence threads are common and that they are attenuated in a few periods. In addition, observers have also reported the presence of material flows in such prominence fine-structures. ... More
The effect of the solar corona on the attenuation of small-amplitude prominence oscillations. I. Longitudinal magnetic fieldApr 12 2007Jun 12 2007Context. One of the typical features shown by observations of solar prominence oscillations is that they are damped in time and that the values of the damping times are usually between one and three times the corresponding oscillatory period. However, ... More
Magnetohydrodynamic Waves in a Partially Ionized Filament ThreadApr 20 2009May 06 2009Oscillations and propagating waves are commonly seen in high-resolution observations of filament threads, i.e., the fine-structures of solar filaments/prominences. Since the temperature of prominences is typically of the order of 10^4 K, the prominence ... More
New results on the baryon decay Lambda_b -> Lambda_c ell nu in Heavy Quark Effective TheoryFeb 18 2012The baryon differential spectrum of the baryon decay $\Lambda_b \to \Lambda_c \ell \bar{\nu}_\ell$ will be measured in detail at LHCb. We obtain new results on the form factors in the heavy quark expansion of Heavy Quark Effective Theory that can be useful ... More
The role of Rayleigh-Taylor instabilities in filament threadsMar 20 2012Many solar filaments and prominences show short-lived horizontal threads lying parallel to the photosphere. In this work the possible link between Rayleigh-Taylor instabilities and thread lifetimes is investigated. This is done by calculating the eigenmodes ... More
Time damping of non-adiabatic magnetohydrodynamic waves in a partially ionized prominence plasma: Effect of heliumOct 15 2009Prominences are partially ionized, magnetized plasmas embedded in the solar corona. Damped oscillations and propagating waves are commonly observed. These oscillations have been interpreted in terms of magnetohydrodynamic (MHD) waves. Ion-neutral collisions ... More
Constraints on neutrino and dark radiation interactions using cosmological observationsMay 16 2011Jan 02 2012Observations of the cosmic microwave background (CMB) and large-scale structure (LSS) provide a unique opportunity to explore the fundamental properties of the constituents that compose the cosmic dark radiation background (CDRB), of which the three standard ... More
Mock Catalogs for the DEEP2 redshift surveyNov 10 2003Feb 12 2004We present a set of mock redshift catalogs, constructed from N-body simulations, designed to mimic the DEEP2 survey. Galaxies with a range of luminosities are placed within virialized halos in the simulation using a variant of the halo model. The halo ... More
Scenario for Spin Glass Phase with Infinitely Many StatesDec 13 2004Jun 07 2005A possible phase in short-range spin glasses exhibiting infinitely many equilibrium states is proposed and characterized in real space. Experimental signatures in equilibrating systems measured with scanning probes are discussed. Some models with correlations ... More
The impact of charge symmetry and charge independence breaking on the properties of neutrons and protons in isospin-asymmetric nuclear matterMay 26 2012We investigate the effects of charge independence and charge symmetry breaking in neutron-rich matter. We consider neutron and proton properties in isospin-asymmetric matter at normal densities as well as the high-density neutron matter equation of state ... More
Normal-mode-based analysis of electron plasma waves with second-order Hermitian formalismDec 27 2017The classic problem of the dynamic evolution of Langmuir electron waves in a collisionless plasma and their Landau damping is cast as a second-order, self-adjoint problem with a continuum spectrum of real and positive squared frequencies. The corresponding ... More
$R$-Parity Violation and Flavour ViolationSep 10 1996The MSSM with $R$-Parity violation allows flavour changing neutral currents through two mechanisms, directly through one loop diagrams, and indirectly through the generation of flavour violation in the sparticle sector. We discuss the use of these mechanisms ... More
Interactive Ant Colony Optimisation (iACO) for Early Lifecycle Software DesignDec 21 2012Jun 23 2014Software design is crucial to successful software development, yet is a demanding multi-objective problem for software engineers. In an attempt to assist the software designer, interactive (i.e. human in-the-loop) meta-heuristic search techniques such ... More
Solar Neutrino Data and Its ImplicationsMar 17 1992The complete and concurrent Homestake and Kamiokande solar neutrino data sets (including backgrounds), when compared to detailed model predictions, provide no unambiguous indication of the solution to the solar neutrino problem. All neutrino-based solutions, ... More
A Tiled-Table Convention for Compressing FITS Binary TablesJan 06 2012This document describes a convention for compressing FITS binary tables that is modeled after the FITS tiled-image compression method (White et al. 2009) that has been in use for about a decade. The input table is first optionally subdivided into tiles, ... More
Problems in a weakless universeSep 05 2006The fact that life has evolved in our universe constrains the laws of physics. The anthropic principle proposes that these constraints are sometimes very tight and can be used to explain in a sense the corresponding laws. Recently a "disproof" of the ... More
The PSCz catalogueSep 10 1999We present the catalogue and redshift data for the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. The uniformity, completeness and data quality are assessed, and guidelines and caveats for its use are given.
Multiplicity and Optical Excess Across the Substellar Boundary in TaurusFeb 20 2006We present the results of a high-resolution imaging survey of 22 brown dwarfs and very low mass stars in the nearby (~145 pc) young (~1-2 Myr) low-density star-forming region Taurus-Auriga. We obtained images with the Advanced Camera for Surveys/High ... More
Near-Infrared Scanning Cavity Ringdown for Optical Loss Characterization of SupermirrorsMar 22 2019Apr 30 2019A cavity ringdown system for probing the spatial variation of optical loss across high-reflectivity mirrors is described. This system is employed to examine substrate-transferred crystalline supermirrors and quantify the effect of manufacturing process ... More
Pulsar Timing at the Deep Space NetworkMar 03 2017The 70-m DSN's Deep Space Station antenna 14 (DSS-14) at Goldstone has recently been outfitted with instrumentation to enable pulsar searching and timing operation. Systems capable of similar operations are undergoing installation at DSS-63, and are planned ... More
Optimal DN encoding for CCD detectorsOct 20 2009Image compression has been a frequent topic of presentations at ADASS. Compression is often viewed as just a technique to fit more data into a smaller space. Rather, the packing of data - its "density" - affects every facet of local data handling, long ... More
Near-Infrared Scanning Cavity Ringdown for Optical Loss Characterization of SupermirrorsMar 22 2019A cavity ringdown system for probing the spatial variation of optical loss across high-reflectivity mirrors is described. This system is employed to examine substrate-transferred crystalline supermirrors and quantify the effect of manufacturing process ... More
Multiplicity at the Stellar/Substellar Boundary in Upper ScorpiusJul 20 2005We present the results of a high-resolution imaging survey of 12 brown dwarfs and very low mass stars in the closest (~145 pc) young (~5 Myr) OB association, Upper Scorpius. We obtained images with the Advanced Camera for Surveys/High Resolution Camera ... More
The dynamics of spontaneous hydrogen segregation in LaFe$_{13-x}$Si$_x$H$_y$Mar 07 2014May 07 2014By means of time- and temperature-dependent magnetization measurements, we demonstrate that the timescale of hydrogen diffusion in partially-hydrogenated LaFe$_{13-x}$Si$_x$H$_y$ is of the order of hours, when the material is held at temperatures close ... More
Transverse oscillations of flowing prominence threads observed with HinodeMar 18 2008Apr 03 2008Recent observations with the Hinode Solar Optical Telescope display an active region prominence whose fine threads oscillate in the vertical direction as they move along a path parallel to the photosphere. A seismological analysis of this event is carried ... More
Lagrangian perturbations at order 1/m$_{\bf Q}$ and the non-forward amplitude in Heavy Quark Effective TheoryOct 13 2005We pursue the program of the study of the non-forward amplitude in HQET. We obtain new sum rules involving the elastic subleading form factors $\chi_i(w)$ $(i = 1,2, 3)$ at order $1/m_Q$ that originate from the ${\cal L}_{kin}$ and ${\cal L}_{mag}$ perturbations ... More
The spatial damping of magnetohydrodynamic waves in a flowing partially ionised prominence plasmaJan 27 2010Solar prominences are partially ionised plasmas displaying flows and oscillations. These oscillations show time and spatial damping and, commonly, have been explained in terms of magnetohydrodynamic (MHD) waves. We study the spatial damping of linear ... More
Isochores Merit the Prefix 'Iso'Sep 20 2002The isochore concept in human genome sequence was challenged in an analysis by the International Human Genome Sequencing Consortium (IHGSC). We argue here that a statement in IGHSC analysis concerning the existence of isochore is incorrect, because it ... More
Bounds on the derivatives of the Isgur-Wise function from sum rules in the heavy quark limit of QCDOct 16 2002Nov 06 2002Using the OPE and the trace formalism, we have obtained a number of sum rules in the heavy quark limit of QCD that include the sum over all excited states for any value $j^P$ of the light cloud. We show that these sum rules imply that the elastic Isgur-Wise ... More
On the support of neutrals against gravity in solar prominencesMar 18 2015Cool and dense prominences found in the solar atmosphere are known to be partially ionized because of their relative low temperature. In this Letter, we address the long-standing problem of how the neutral component of the plasma in prominences is supported ... More
Damping of filament thread oscillations: effect of the slow continuumFeb 03 2009Mar 19 2009Transverse oscillations of small amplitude are commonly seen in high-resolution observations of filament threads, i.e. the fine-structures of solar filaments/prominences, and are typically damped in a few periods. Kink wave modes supported by the thread ... More
Global shallow water magnetohydrodynamic waves in the solar tachoclineOct 23 2008Dec 05 2008We derive analytical solutions and dispersion relations of global magnetic Poincar\'e (magneto-gravity) and magnetic Rossby waves in the approximation of shallow water magnetohydrodynamics. The solutions are obtained in a rotating spherical coordinate ... More
Resonantly damped surface and body MHD waves in a solar coronal slab with oblique propagationAug 28 2007The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-$\beta$ configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is considered both surface ... More
Magnetic Rossby waves in the solar tachocline and Rieger-type periodicitiesNov 24 2009Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive ... More
Novel Exploration Techniques (NETs) for Malaria Policy InterventionsDec 01 2017The task of decision-making under uncertainty is daunting, especially for problems which have significant complexity. Healthcare policy makers across the globe are facing problems under challenging constraints, with limited tools to help them make data ... More
Sum rules in the heavy quark limit of QCD and Isgur-Wise functionsDec 10 2004Using the OPE, we formulate new sum rules in the heavy quark limit of QCD. These sum rules imply that the elastic Isgur-Wise function $\xi (w)$ is an alternate series in powers of $(w-1)$. Moreover, one gets that the $n$-th derivative of $\xi (w)$ at ... More
The Properties of Long-Period Variables in the Large Magellanic Cloud from MACHOAug 12 2008We present a new analysis of the long-period variables in the Large Magellanic Cloud (LMC) from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample ... More
Spinon-holon interactions in an anisotropic t-J chain: a comprehensive studyMay 22 2007Sep 10 2007We consider a generalization of the one-dimensional t-J model with anisotropic spin-spin interactions. We show that the anisotropy leads to an effective attractive interaction between the spinon and holon excitations, resulting in a localized bound state. ... More
Persistence and Memory in Patchwork Dynamics for Glassy ModelsAug 05 2007Aug 10 2007Slow dynamics in disordered materials prohibits direct simulation of their rich nonequilibrium behavior at large scales. "Patchwork dynamics" is introduced to mimic relaxation over a very broad range of time scales by equilibrating or optimizing directly ... More
Gravity darkening and brightening in binariesMar 12 2012Aug 07 2012We apply a von Zeipel gravity darkening model to corotating binaries to obtain a simple, analytical expression for the emergent radiative flux from a tidally distorted primary orbiting a point-mass secondary. We adopt a simple Roche model to determine ... More
A Correlation Between Circumstellar Disks and Rotation in the Upper Scorpius OB AssociationOct 03 2011We present projected rotational velocities for 20 early-type (B8-A9) and 74 late-type (F2-M8) members of the ~5 Myr old Upper Scorpius OB Association derived from high dispersion optical spectra obtained with the High Resolution Echelle Spectrometer (HIRES) ... More
Lossless Astronomical Image Compression and the Effects of NoiseMar 12 2009We compare a variety of lossless image compression methods on a large sample of astronomical images and show how the compression ratios and speeds of the algorithms are affected by the amount of noise in the images. In the ideal case where the image pixel ... More
A Near-Infrared Spectral Template for QuasarsNov 22 2005We present a near-infrared quasar composite spectrum spanning the wavelength range 0.58 - 3.5 um. The spectrum has been constructed from observations of 27 quasars obtained at the NASA IRTF telescope and satisfying the criteria Ks < 14.5 and Mi < -23; ... More
Heat and momentum transport in turbulent horizontal convection at low Prandtl numbersMay 29 2018The transition to a new turbulent regime in horizontal convection in the case of low Prandtl numbers is analyzed using the Shishkina, Grossmann & Lohse (SGL) theory. The flow driven by the horizontal gradient along a horizontal surface, perpendicular ... More
Transverse oscillations of a multi-stranded loopDec 22 2009May 10 2010We investigate the transverse oscillations of a line-tied multi-stranded coronal loop composed of several parallel cylindrical strands. First, the collective fast normal modes of the loop are found with the T-matrix theory. There is a huge quantity of ... More
The Isgur-Wise function in the BPS limitNov 02 2006From sum rules in the heavy quark limit of QCD, using the non-forward amplitude, we demonstrate that if the slope rho^2 = -xsi'(1) of the Isgur-Wise function xsi(w) attains its lower bound 3/4 (as happens in the BPS limit proposed by Uraltsev), the IW ... More
Explicit form of the Isgur-Wise function in the BPS limitApr 06 2006Oct 13 2006Using previously formulated sum rules in the heavy quark limit of QCD, we demonstrate that if the slope rho^2 = -xi'(1) of the Isgur-Wise function xi(w) attains its lower bound 3/4, then all the derivatives (-1)^L xi^(L)(1) attain their lower bounds (2L+1)!!/2^(2L), ... More
Towards Schwinger production of magnetic monopoles in heavy-ion collisionsFeb 12 2019Magnetic monopoles may be produced by the Schwinger effect in the strong magnetic fields of peripheral heavy-ion collisions. We review the form of the electromagnetic fields in such collisions and calculate from first principles the cross section for ... More
Timing the Neutrino Signal of a Galactic SupernovaApr 25 2019We study several methods for timing the neutrino signal of a galactic supernova for different detectors via Monte Carlo simulations. We find that, for the methods we studied, both Hyper-Kamiokande and IceCube can reach precisions of $\sim1\,$ms for the ... More
Transverse oscillations of two coronal loopsJul 05 2007Dec 11 2007We study transverse fast magnetohydrodynamic waves in a system of two coronal loops modeled as smoothed, dense plasma cylinders in a uniform magnetic field. The collective oscillatory properties of the system due to the interaction between the individual ... More
Scattering and delay time for 1D asymmetric potentials: the step-linear and the step-exponential casesFeb 15 2011May 24 2016We analyze the quantum-mechanical behavior of a system described by a one-dimensional asymmetric potential constituted by a step plus (i) a linear barrier or (ii) an exponential barrier. We solve the energy eigenvalue equation by means of the integral ... More
Quasi-biennial oscillations in the solar tachocline caused by magnetic Rossby wave instabilitiesNov 05 2010Quasi-biennial oscillations (QBO) are frequently observed in the solar activity indices. However, no clear physical mechanism for the observed variations has been suggested so far. Here we study the stability of magnetic Rossby waves in the solar tachocline ... More
The statistical significance of the N-S asymmetry of solar activity revisitedSep 12 2007The main aim of this study is to point out the difficulties found when trying to assess the statistical significance of the North-South asymmetry (hereafter SSNSA) of the most usually considered time series of solar activity. First of all, we distinguish ... More
Bounds on the derivatives of the Isgur-Wise function with a non-relativistic light quarkMay 24 2004Jul 15 2004In a preceeding study in the heavy quark limit of QCD, it has been demonstrated that the best lower bound on the curvature of the Isgur-Wise function Xsi(w) is Xsi"(1) > (4rho2+3(rho2)2) > 15/16. The quadratic term (rho2)2 is dominant in a non-relativistic ... More
The decays $\bar{B} \to D^{**}π$ and the Isgur-Wise functions $τ_{1/2}(w)$, $τ_{3/2}(w)$Apr 22 2005Oct 10 2005We perform a phenomenological analysis of the decays $B \to D^{**}\pi$, where $D^{**}$ is a $P$-wave excited meson with total angular momentum $j = {1 \over 2}$ or ${3 \over 2}$ for the light cloud, recently measured by the Belle Collaboration in the ... More
Subleading form factors at order 1/m_Q in terms of leading quantities using the non-forward amplitude in HQETJul 15 2004Mar 01 2005We consider the non-forward amplitude within the Heavy Quark Effective theory. We show that one can obtain new information on the subleading corrections in 1/m_Q. We illustrate the method by deriving new simple relations between the functions Xsi_3(w) ... More
Spectral line width decrease in the solar corona: resonant energy conversion from Alfv{é}n to acoustic wavesMar 13 2007Observations reveal an increase with height of the line width of several coronal spectral lines probably caused by outwardly propagating Alfv{\'e}n waves. However, the spectral line width sometimes shows a sudden decrease at a height 0.1-0.2 R, where ... More
Transverse oscillations of systems of coronal loopsSep 24 2008We study the collective kinklike normal modes of a system of several cylindrical loops using the T-matrix theory. Loops that have similar kink frequencies oscillate collectively with a frequency which is slightly different from that of the individual ... More
The Step-Harmonic PotentialDec 16 2009Jul 15 2010We analyze the behavior of a quantum system described by a one-dimensional asymmetric potential consisting of a step plus a harmonic barrier. We solve the eigenvalue equation by the integral representation method, which allows us to classify the independent ... More
Seesaw model in SO(10) with an upper limit on right-handed neutrino massesJul 23 2011Jan 30 2012In the framework of SO(10) gauge unification and the seesaw mechanism, we show that the upper bound on the mass of the heaviest right-handed neutrino $M_{R_3} < 3 \times 10^{11}$ GeV, given by the Pati-Salam intermediate scale of $B-L$ spontaneous symmetry ... More
Sum rules for leading and subleading form factors in Heavy Quark Effective Theory using the non-forward amplitudeNov 07 2005Within the OPE, we the new sum rules in Heavy Quark Effective Theory in the heavy quark limit and at order 1/m_Q, using the non-forward amplitude. In particular, we obtain new sum rules involving the elastic subleading form factors chi_i(w) (i = 1,2, ... More
The tensor force in Heavy Quark Effective TheoryOct 13 2005Jun 20 2006We extend the formalism of Leibovich, Ligeti, Stewart and Wise in the 1/m_Q expansion of Heavy Quark Effective Theory for the B semileptonic decays into excited D[(3/2)^+] mesons to the opposite parity states D[(3/2)^-]. For D[(3/2)^+] the 1/m_Q current ... More
Mock galaxy catalogs using the quick particle mesh methodSep 21 2013Oct 23 2013Sophisticated analysis of modern large-scale structure surveys requires mock catalogs. Mock catalogs are used to optimize survey design, test reduction and analysis pipelines, make theoretical predictions for basic observables and propagate errors through ... More
Numerical Model for Conduction-Cooled Current Lead Heat LoadsSep 13 2012Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories ... More
New Catalogs of Compact Radio Sources in the Galactic PlaneJan 27 2005May 19 2005Archival data have been combined with recent observations of the Galactic plane using the Very Large Array to create new catalogs of compact centimetric radio sources. The 20 cm source catalog covers a longitude range of -20 deg < l < 120 deg; the latitude ... More
Time-Dependence of the Mass Accretion Rate in Cluster Cooling FlowsMay 11 2000We analyze two time-dependent cluster cooling flow models in spherical symmetry. The first assumes that the intracluster gas resides in a static external potential, and includes the effects of optically thin radiative cooling and mass deposition. This ... More
Data-Driven Control of Distributed Reconfigurable Production-Inventory SystemsFeb 23 2019We analyze the value of mobile production capacity and transshipment in a supply chain with geographically distributed production facilities and epoch-dependent demands. We describe the L location, Y mobile production unit problem as a problem of sequential ... More
Polarisation studies in H-t productionJan 29 2013We summarise a recent study looking at top quark polarisation effects in charged Higgs boson production. Lab frame angular and energy observables relating to leptonic decays of top quarks are analysed, and corresponding asymmetry parameters obtained. ... More
Real-Root Preserving Differential Operator Representations of Orthogonal PolynomialsJul 17 2017In this paper, we study linear transformations of the form $T[x^n]=P_n(x)$ where $\{P_n(x)\}$ is an orthogonal polynomial system. Of particular interest is understanding when these operators preserve real-rootedness in polynomials. It is known that when ... More
The Boundary Cosmological Constant in Stable 2D Quantum GravityJun 17 1992We study further the r\^ole of the boundary operator $\O_B$ for macroscopic loop length in the stable definition of 2D quantum gravity provided by the $[{\tilde P},Q]=Q$ formulation. The KdV flows are supplemented by an additional flow with respect to ... More
The Last of FIRST: The Final Catalog and Source IdentificationsJan 06 2015Jan 09 2015The FIRST survey, begun over twenty years ago, provides the definitive high-resolution map of the radio sky. This VLA survey reaches a 20cm detection sensitivity of 1 mJy over 10,575 deg**2 largely coincident with the SDSS area. Images and a catalog containing ... More
Optimal transient growth in thin-interface internal solitary wavesAug 30 2017The dynamics of perturbations to large-amplitude Internal Solitary Waves (ISW) in two-layered flows with thin interfaces is analyzed by means of linear optimal transient growth methods. Optimal perturbations are computed through direct-adjoint iterations ... More
Radiative Corrections to Higgs Boson Masses in the Next-to-Minimal Supersymmetric Standard ModelAug 20 1993We perform a systematic study of radiative corrections to the masses of the Higgs bosons in the minimal supersymmetric standard model (MSSM) augmented by a single gauge singlet, the so-called next-to-minimal supersymmetric standard model (NMSSM). Our ... More
Short-Term Memory in Orthogonal Neural NetworksFeb 17 2004We study the ability of linear recurrent networks obeying discrete time dynamics to store long temporal sequences that are retrievable from the instantaneous state of the network. We calculate this temporal memory capacity for both distributed shift register ... More
Analyzing data from DASIDec 20 1999We present an optimized layout of horn positions for the Degree Angular Scale Interferometer (DASI), which provides good coverage of the u-v plane and 3-fold symmetry. We investigate how an optimal subspace filtering analysis of a single pointing of DASI ... More
Optimal Compression of Floating-point Astronomical Images Without Significant Loss of InformationJul 07 2010We describe a compression method for floating-point astronomical images that gives compression ratios of 6 -- 10 while still preserving the scientifically important information in the image. The pixel values are first preprocessed by quantizing them into ... More
High-Dispersion Optical Spectra of Nearby Stars Younger Than The SunJun 04 2007We present high-dispersion (R~16,000) optical (3900-8700 A) spectra of 390 stars obtained with the Palomar 60 inch telescope. The majority of stars observed are part of the Spitzer Legacy Science Program "The Formation and Evolution of Planetary Systems." ... More
A Radio Counterpart for the Unidentified TeV Source HESS J1813-178: The Radio-Gamma-Ray ConnectionMay 18 2005We discovered independently the shell-type supernova remnant G12.82-0.02, recently reported by Brogan et al. (2005), which is coincident with the unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic plane. Estimating the ambient ... More
Radio-Selected Quasars in the Sloan Digital Sky SurveySep 22 2009We have conducted a pilot survey for z>3.5 quasars by combining the FIRST radio survey with the SDSS. While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves the discovery ... More
X-ray Binaries and Globular Clusters in Elliptical GalaxiesApr 10 2002The X-ray emission from normal elliptical galaxies has two major components: soft emission from diffuse gas and harder emission from populations of accreting (low-mass) stellar X-ray binaries (LMXB). If LMXB populations are tied to the field stellar populations ... More
Matching control laws for a ball and beam systemMar 27 2000This note describes a method for generating an infinite-dimensional family of nonlinear control laws for underactuated systems. For a ball and beam system, the entire family is found explicitly.
A Study of Optical Observing Techniques for Extra-Galactic Supernova Remnants: Case of NGC 300Feb 20 2012We present the results of a study of observational and identification techniques used for surveys and spectroscopy of candidate supernova remnants (SNRs) in the Sculptor Group galaxy NGC 300. The goal of this study was to investigate the reliability of ... More
Inventory Control with Modulated Demand and a Partially Observed Modulation ProcessMar 18 2018We consider a periodic review inventory control problem having an underlying modulation process that affects demand and that is partially observed by the uncensored demand process and a novel additional observation data (AOD) process. Letting $K$ be the ... More
Partially Observed, Multi-objective Markov GamesApr 16 2014The intent of this research is to generate a set of non-dominated policies from which one of two agents (the leader) can select a most preferred policy to control a dynamic system that is also affected by the control decisions of the other agent (the ... More
Unification Constraints in the Next-to-Minimal Supersymmetric Standard ModelJun 14 1994Oct 06 1995We perform a renormalisation group analysis of the next-to-minimal supersymmetric standard model (NMSSM) based on the following constraints: two-loop gauge coupling unification at a variable scale $M_X$, running the gauge couplings through the low energy ... More
Interferometric Observation of Cosmic Microwave Background AnisotropiesDec 15 1997Aug 31 1998We present a formalism for analyzing interferometric observations of Cosmic Microwave Background (CMB) anisotropy and polarization data. The formalism is based upon the ell-space expansion of the angular power spectrum favoured in recent years. Explicit ... More
Binding of holons and spinons in the one-dimensional anisotropic t-J modelFeb 08 2007Jun 29 2007We study the binding of a holon and a spinon in the one-dimensional anisotropic t-J model using a Bethe-Salpeter equation approach, exact diagonalization, and density matrix renormalization group methods on chains of up to 128 sites. We find that holon-spinon ... More
Extracting quantum dynamics from genetic learning algorithms through principal control analysisJan 06 2004Jul 15 2004Genetic learning algorithms are widely used to control ultrafast optical pulse shapes for photo-induced quantum control of atoms and molecules. An unresolved issue is how to use the solutions found by these algorithms to learn about the system's quantum ... More
Double Lobed Radio Quasars from the Sloan Digital Sky SurveyOct 26 2005We have combined a sample of 44984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio environment within 450", ... More