Results for "Tyson B. Littenberg"

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Astro2020 Decadal Science White Paper: Gravitational Wave Survey of Galactic Ultra Compact BinariesMar 13 2019Ultra-compact binaries (UCBs) are systems containing compact or degenerate stars with orbital periods less than one hour. Tens of millions of UCBs are predicted to exist within theGalaxy emitting gravitational waves (GWs) at mHz frequencies. Combining ... More
A detection pipeline for galactic binaries in LISA dataJun 30 2011The Galaxy is suspected to contain hundreds of millions of binary white dwarf systems, a large fraction of which will have sufficiently small orbital period to emit gravitational radiation in band for space-based gravitational wave detectors such as the ... More
Binary White Dwarfs as Laboratories for Extreme Gravity with LISANov 02 2018The observation of low-frequency gravitational waves with the Laser Interferometer Space Antenna will allow the study of new sources of gravitational radiation that are not accessible by ground-based instruments. Gravitational wave sources provide invaluable ... More
BayesLine: Bayesian Inference for Spectral Estimation of Gravitational Wave Detector NoiseOct 14 2014Gravitational wave data from ground-based detectors is dominated by instrument noise. Signals will be comparatively weak, and our understanding of the noise will influence detection confidence and signal characterization. Mis-modeled noise can produce ... More
Tests of Bayesian Model Selection Techniques for Gravitational Wave AstronomyApr 13 2007Nov 08 2007The analysis of gravitational wave data involves many model selection problems. The most important example is the detection problem of selecting between the data being consistent with instrument noise alone, or instrument noise and a gravitational wave ... More
A Bayesian Approach to the Detection Problem in Gravitational Wave AstronomyFeb 02 2009Jul 16 2009The analysis of data from gravitational wave detectors can be divided into three phases: search, characterization, and evaluation. The evaluation of the detection - determining whether a candidate event is astrophysical in origin or some artifact created ... More
Separating Gravitational Wave Signals from Instrument ArtifactsAug 09 2010Central to the gravitational wave detection problem is the challenge of separating features in the data produced by astrophysical sources from features produced by the detector. Matched filtering provides an optimal solution for Gaussian noise, but in ... More
BayesWave: Bayesian Inference for Gravitational Wave Bursts and Instrument GlitchesOct 14 2014May 07 2015A central challenge in Gravitational Wave Astronomy is identifying weak signals in the presence of non-stationary and non-Gaussian noise. The separation of gravitational wave signals from noise requires good models for both. When accurate signal models ... More
Rapid gravitational wave parameter estimation with a single spin: Systematic uncertainties in parameter estimation with the SpinTaylorF2 approximationJun 19 2015Reliable low-latency gravitational wave parameter estimation is essential to target limited electromagnetic followup facilities toward astrophysically interesting and electromagnetically relevant sources of gravitational waves. In this study, we examine ... More
Systematic errors in low latency gravitational wave parameter estimation impact electromagnetic follow-up observationsJan 11 2016Mar 01 2016Among the most eagerly anticipated opportunities made possible by Advanced LIGO/Virgo are multimessenger observations of compact mergers. Optical counterparts may be short-lived so rapid characterization of gravitational wave (GW) events is paramount ... More
Fortifying the characterization of binary mergers in LIGO dataJul 31 2013The study of compact binary in-spirals and mergers with gravitational wave observatories amounts to optimizing a theoretical description of the data to best reproduce the true detector output. While most of the research effort in gravitational wave data ... More
A soft Oka principle for proper holomorphic embeddings of open Riemann surfaces into $(\mathbb{C}^*)^2$Mar 26 2014May 06 2014Let $X$ be an open Riemann surface. We prove an Oka property on the approximation and interpolation of continuous maps $X \to (\mathbb{C}^*)^2$ by proper holomorphic embeddings, provided that we permit a smooth deformation of the complex structure on ... More
What we can learn from multi-band observations of black hole binariesMar 10 2019The LIGO/Virgo gravitational-wave (GW) interferometers have to-date detected ten merging black hole (BH) binaries, some with masses considerably larger than had been anticipated. Stellar-mass BH binaries at the high end of the observed mass range (with ... More
Enabling high confidence detections of gravitational-wave burstsNov 27 2015With the advanced LIGO and Virgo detectors taking observations the detection of gravitational waves is expected within the next few years. Extracting astrophysical information from gravitational wave detections is a well-posed problem and thoroughly studied ... More
Neutron stars versus black holes: probing the mass gap with LIGO/VirgoMar 11 2015Jun 16 2015Inspirals and mergers of black hole (BHs) and/or neutron star (NSs) binaries are expected to be abundant sources for ground-based gravitational-wave (GW) detectors. We assess the capabilities of Advanced LIGO and Virgo to measure component masses using ... More
Systematic biases in parameter estimation of binary black-hole mergersOct 02 2012Parameter estimation of binary-black-hole merger events in gravitational-wave data relies on matched-filtering techniques, which, in turn, depend on accurate model waveforms. Here we characterize the systematic biases introduced in measuring astrophysical ... More
Prospects for observing ultra-compact binaries with space-based gravitational wave interferometers and optical telescopesJul 20 2012Aug 24 2012Space-based gravitational wave interferometers are sensitive to the galactic population of ultra-compact binaries. An important subset of the ultra-compact binary population are those stars that can be individually resolved by both gravitational wave ... More
On the properties of the massive binary black hole merger GW170729Mar 15 2019We present a detailed investigation into the properties of GW170729, the gravitational wave with the most massive and distant source confirmed to date. We employ an extensive set of waveform models, including new improved models that incorporate the effect ... More
Astrophysical Model Selection in Gravitational Wave AstronomySep 27 2012Theoretical studies in gravitational wave astronomy have mostly focused on the information that can be extracted from individual detections, such as the mass of a binary system and its location in space. Here we consider how the information from multiple ... More
Leveraging waveform complexity for confident detection of gravitational wavesSep 21 2015Jan 12 2016The recent completion of Advanced LIGO suggests that gravitational waves (GWs) may soon be directly observed. Past searches for gravitational-wave transients have been impacted by transient noise artifacts, known as glitches, introduced into LIGO data ... More
Robust parameter estimation for compact binaries with ground-based gravitational-wave observations using the LALInference software librarySep 25 2014Feb 16 2015The Advanced LIGO and Advanced Virgo gravitational wave (GW) detectors will begin operation in the coming years, with compact binary coalescence events a likely source for the first detections. The gravitational waveforms emitted directly encode information ... More
Parameter estimation for gravitational-wave bursts with the BayesWave pipelineDec 06 2016Apr 10 2017We provide a comprehensive multi-aspect study on the performance of a pipeline used by the LIGO-Virgo Collaboration for estimating parameters of gravitational-wave bursts. We add simulated signals with four different morphologies (sine-Gaussians, Gaussians, ... More
Systematic and statistical errors in a bayesian approach to the estimation of the neutron-star equation of state using advanced gravitational wave detectorsFeb 20 2014Advanced ground-based gravitational-wave detectors are capable of measuring tidal influences in binary neutron-star systems. In this work, we report on the statistical uncertainties in measuring tidal deformability with a full Bayesian parameter estimation ... More
Parameter estimation for gravitational-wave bursts with the BayesWave pipelineDec 06 2016We provide a comprehensive multi-aspect study on the performance of a pipeline used by the LIGO-Virgo Collaboration for estimating parameters of gravitational-wave bursts. We add simulated signals with four different morphologies (sine-Gaussians, Gaussians, ... More
Integral Curvature Representation and Matching Algorithms for Identification of Dolphins and WhalesAug 25 2017We address the problem of identifying individual cetaceans from images showing the trailing edge of their fins. Given the trailing edge from an unknown individual, we produce a ranking of known individuals from a database. The nicks and notches along ... More
Cosmology with the Large Synoptic Survey Telescope: an OverviewJul 21 2017Mar 09 2018The Large Synoptic Survey Telescope (LSST) is a high etendue imaging facility that is being constructed atop Cerro Pachon in Northern Chile. It is scheduled to begin science operations in 2022. With an 8.4m (6.5m effective) aperture, a three-mirror design ... More
Low-frequency gravitational-wave science with eLISA/NGOFeb 03 2012Sep 12 2012We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from ... More
Mitigation of the instrumental noise transient in gravitational-wave data surrounding GW170817Aug 10 2018Oct 20 2018In the coming years gravitational-wave detectors will undergo a series of improvements, with an increase in their detection rate by about an order of magnitude. Routine detections of gravitational-wave signals promote novel astrophysical and fundamental ... More
Holographic Algorithms Beyond MatchgatesJul 29 2013Jan 10 2018Holographic algorithms introduced by Valiant are composed of two ingredients: matchgates, which are gadgets realizing local constraint functions by weighted planar perfect matchings, and holographic reductions, which show equivalences among problems with ... More
Measurements and Simulations of the Brighter-Fatter Effect in CCD SensorsMar 16 2017Reduction of images and science analysis from ground-based telescopes such as the LSST requires detailed knowledge of the PSF of the image, which includes components attributable to the instrument as well as components attributable to the atmosphere. ... More
Distinguishing black-hole spin-orbit resonances by their gravitational wave signatures. II: Full parameter estimationJul 20 2015Feb 15 2016Gravitational waves from coalescing binary black holes encode the evolution of their spins prior to merger. In the post-Newtonian regime and on the precession timescale, this evolution has one of three morphologies, with the spins either librating around ... More
Basic Parameter Estimation of Binary Neutron Star Systems by the Advanced LIGO/Virgo NetworkSep 12 2013Feb 12 2014Within the next five years, it is expected that the Advanced LIGO/Virgo network will have reached a sensitivity sufficient to enable the routine detection of gravitational waves. Beyond the initial detection, the scientific promise of these instruments ... More
A Holant Dichotomy: Is the FKT Algorithm Universal?May 12 2015We prove a complexity dichotomy for complex-weighted Holant problems with an arbitrary set of symmetric constraint functions on Boolean variables. This dichotomy is specifically to answer the question: Is the FKT algorithm under a holographic transformation ... More
Cantor set arithmeticNov 23 2017Every element $u$ of $[0,1]$ can be written in the form $u=x^2y$, where $x,y$ are elements of the Cantor set $C$. In particular, every real number between zero and one is the product of three elements of the Cantor set. On the other hand the set of real ... More
Characterization of LSST CCDs Using Realistic Images, Before First LightAug 01 2018The 3.2 gigapixel LSST camera, an array of 189 thick fully-depleted CCDs, will repeatedly image the southern sky and accomplish a wide variety of science goals. However, its trove of tens of billions of object images implies stringent requirements on ... More
Proposal for an Experimental Program in Neutrino Physics and Proton Decay in the Homestake LaboratoryAug 08 2006Jan 12 2007This report is intended to describe first, the principal physics reasons for an ambitious experimental program in neutrino physics and proton decay based on construction of a series of massive water Cherenkov detectors located deep underground (4850 ft) ... More
Optical Light Curves of the Type Ia Supernovae 1990N and 1991TSep 25 1997We present UBVRI light curves for the bright Type Ia supernovae SN 1990N in NGC 4639 and SN 1991T in NGC 4527 based on photometry gathered in the course of the Calan/Tololo supernova program. Both objects have well-sampled light curves starting several ... More
Gravity Spy: Integrating Advanced LIGO Detector Characterization, Machine Learning, and Citizen ScienceNov 14 2016Feb 28 2017(abridged for arXiv) With the first direct detection of gravitational waves, the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) has initiated a new field of astronomy by providing an alternate means of sensing the universe. The extreme ... More
Tests of General Relativity and Fundamental Physics with Space-based Gravitational Wave DetectorsMar 07 2019Low-frequency gravitational-wave astronomy can perform precision tests of general relativity and probe fundamental physics in a regime previously inaccessible. A space-based detector will be a formidable tool to explore gravity's role in the cosmos, potentially ... More
The Chain of Implicit Trust: An Analysis of the Web Third-party Resources LoadingJan 23 2019Feb 18 2019The Web is a tangled mass of interconnected services, where websites import a range of external resources from various third-party domains. However, the latter can further load resources hosted on other domains. For each website, this creates a dependency ... More
Local Structure of the Superconductor K0.8Fe1.6+xSe2: Evidence of Large Structural DisorderNov 04 2011The local structure of superconducting single crystals of K0.8Fe1.6+xSe2 with Tc = 32.6 K was studied by x-ray absorption spectroscopy. Near-edge spectra reveal that the average valence of Fe is 2+. The room temperature structure about the Fe, K and Se ... More
Scaling Datalog for Machine Learning on Big DataMar 01 2012Mar 02 2012In this paper, we present the case for a declarative foundation for data-intensive machine learning systems. Instead of creating a new system for each specific flavor of machine learning task, or hardcoding new optimizations, we argue for the use of recursive ... More
Wide-Field Astronomical Surveys in the Next DecadeMar 18 2009Wide-angle surveys have been an engine for new discoveries throughout the modern history of astronomy, and have been among the most highly cited and scientifically productive observing facilities in recent years. This trend is likely to continue over ... More
Two-sided bounds on minimum-error quantum measurement, on the reversibility of quantum dynamics, and on the maximum overlap problem using directional iteratesJul 20 2009Jun 02 2010In a unified framework, we obtain two-sided estimates of the following quantities of interest in quantum information theory: 1.The minimum-error distinguishability of arbitrary ensembles of mixed quantum states. 2.The approximate reversibility of quantum ... More
Error rates of Belavkin weighted quantum measurements and a converse to Holevo's asymptotic optimality theoremJul 10 2009We compare several instances of pure-state Belavkin weighted square-root measurements from the standpoint of minimum-error discrimination of quantum states. The quadratically weighted measurement is proven superior to the so-called "pretty good measurement" ... More
Operator-Schmidt decomposition of the quantum Fourier transform on C^N1 tensor C^N2Oct 13 2002Apr 25 2003Operator-Schmidt decompositions of the quantum Fourier transform on C^N1 tensor C^N2 are computed for all N1, N2 > 1. The decomposition is shown to be completely degenerate when N1 is a factor of N2 and when N1>N2. The first known special case, N1=N2=2^n, ... More
Estimates of non-optimality of quantum measurements and a simple iterative method for computing optimal measurementsFeb 03 2009Feb 14 2009We construct crude estimates for non-optimality of quantum measurements in terms of their violation of Holevo's simplified minimum-error optimality conditions. As an application, we show that a modification of Barnett and Croke's proof of the optimality ... More
Two-sided estimates of minimum-error distinguishability of mixed quantum states via generalized Holevo-Curlander boundsJul 13 2009We prove a concise factor-of-2 estimate for the failure rate of optimally distinguishing an arbitrary ensemble of mixed quantum states, generalizing work of Holevo [Theor. Probab. Appl. 23, 411 (1978)] and Curlander [Ph.D. Thesis, MIT, 1979]. A modification ... More
Acyclic embeddings of open Riemann surfaces into new examples of elliptic manifoldsJul 01 2011The geometric notion of ellipticity for complex manifolds was introduced by Gromov in his seminal 1989 paper on the Oka principle, and is a sufficient condition for a manifold to be Oka. In the current paper we present contributions to three open questions ... More
A strong Oka principle for embeddings of some planar domains into CxC*Nov 18 2010Gromov, in his seminal 1989 paper on the Oka principle, introduced the notion of an elliptic manifold and proved that every continuous map from a Stein manifold to an elliptic manifold is homotopic to a holomorphic map. We show that a much stronger Oka ... More
Gravity Spy: Integrating Advanced LIGO Detector Characterization, Machine Learning, and Citizen ScienceNov 14 2016(abridged for arXiv) With the first direct detection of gravitational waves, the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) has initiated a new field of astronomy by providing an alternate means of sensing the universe. The extreme ... More
Search for the rare decay $K^+\toμ^+ν\barνν$Jun 29 2016Sep 01 2016Evidence of the $K^+\to\mu^+\nu\bar\nu\nu$ decay was searched for using E949 experimental data with an exposure of $1.70\times 10^{12}$ stopped kaons. The data sample is dominated by the backgrond process $K^+\to\mu^+\nu_\mu\gamma$. An upper limit on ... More
Rare Kaon DecaysDec 19 2005Dec 20 2005Recent results in and future prospects for the study of rare kaon decays are reviewed.
Rare Kaon and Pion DecaysDec 04 2002Recent results on rare kaon and pion decays are reviewed and prospects for future experiments are discussed
Report on the second Mock LISA Data ChallengeNov 16 2007The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of several data sets containing simulated instrument noise and gravitational-wave sources ... More
Rare K decay: results and prospectsJan 17 2002Recent results on rare kaon decays are reviewed and prospects for future experiments are discussed.
Study of the decay K+ => pi+,nu,nubar in the momentum region 140<Ppi<199 MeV/cFeb 28 2009Experiment E949 at Brookhaven National Laboratory has observed three new events consistent with the decay K+ => pi+,nu,nubar in the pion momentum region 140 < P_pi < 199 MeV/c in an exposure of 1.71e12 stopped kaons with an estimated total background ... More
Weak Lensing Results from the 75 Square Degree CTIO SurveyOct 28 2002Dec 02 2002We measure seeing-corrected ellipticities for 2 x 10^6 galaxies with magnitude R<23 in 12 widely separated fields totalling 75 deg^2 of sky. At angular scales >30\arcmin, ellipticity correlations are detected at high significance and exhibit nearly the ... More
Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and CalibrationSep 20 2013Large sets of objects with spectroscopic redshift measurements will be needed for imaging dark energy experiments to achieve their full potential, serving two goals:_training_, i.e., the use of objects with known redshift to develop and optimize photometric ... More
Rare Kaon DecaysOct 18 2000The current status of the study of rare kaon decays is reviewed. Future prospects are discussed.
BNL Future PlansFeb 18 1998I discuss the prospects for a fixed target physics program at the AGS in the RHIC era.
Galaxy-Mass Correlations on 10 Mpc Scales in the Deep Lens SurveyAug 19 2012We examine the projected correlation of galaxies with mass from small scales (<few hundred kpc) where individual dark matter halos dominate, out to 15 Mpc where correlated large-scale structure dominates. We investigate these profiles as a function of ... More
Work Function Characterization of the Directionally Solidified LaB6 VB2 EutecticMar 31 2018With its low work function and high mechanical strength, the LaB6/VB2 eutectic system is an interesting candidate for high performance thermionic emitters. For the development of device applications, it is important to understand the origin, value, and ... More
Operator-Schmidt decompositions and the Fourier transform, with applications to the operator-Schmidt numbers of unitariesJun 22 2003Jul 01 2003The operator-Schmidt decomposition is useful in quantum information theory for quantifying the nonlocality of bipartite unitary operations. We construct a family of unitary operators on C^n tensor C^n whose operator-Schmidt decompositions are computed ... More
The Complexity of Planar Boolean #CSP with Complex WeightsDec 11 2012Aug 06 2013We prove a complexity dichotomy theorem for symmetric complex-weighted Boolean #CSP when the constraint graph of the input must be planar. The problems that are #P-hard over general graphs but tractable over planar graphs are precisely those with a holographic ... More
Proper holomorphic immersions in homotopy classes of maps from finitely connected planar domains into CxC*Sep 20 2012Oct 24 2012Gromov, in his seminal 1989 paper on the Oka principle, proved that every continuous map from a Stein manifold into an elliptic manifold is homotopic to a holomorphic map. Previously we have shown that, given a continuous map $X \to \C\times\C^*$ from ... More
An interesting class of Hankel determinantsJul 22 2018Oct 29 2018For small $r$ the Hankel determinants $d_r(n)$ of the sequence $\left({2n+r\choose n}\right)_{n\ge 0}$ are easy to guess and show an interesting modular pattern. For arbitrary $r$ and $n$ no closed formulae are known, but for each positive integer $r$ ... More
Conference summary: Workshop on Precision Astronomy with Fully Depleted CCDs (2014)Jun 22 2015Thick fully depleted CCDs, while enabling wide spectral response, also present challenges in understanding the systematic errors due to 3D charge transport. This 2014 Workshop on Precision Astronomy with Fully Depleted CCDs covered progress that has been ... More
Mathematical Analysis and Dynamic Active Subspaces for a Long term model of HIVApr 15 2016Apr 18 2016Recently, a long-term model of HIV infection dynamics was developed to describe the entire time course of the disease. It consists of a large system of ODEs with many parameters, and is expensive to simulate. In the current paper, this model is analyzed ... More
Tomographic Magnification of Lyman Break Galaxies in The Deep Lens SurveyApr 12 2012Sep 13 2012Using about 450,000 galaxies in the Deep Lens Survey, we present a detection of the gravitational magnification of z > 4 Lyman Break Galaxies by massive foreground galaxies with 0.4 < z < 1.0, grouped by redshift. The magnification signal is detected ... More
Optical Synoptic Telescopes: New Science FrontiersSep 12 2010Over the past decade, sky surveys such as the Sloan Digital Sky Survey have proven the power of large data sets for answering fundamental astrophysical questions. This observational progress, based on a synergy of advances in telescope construction, detectors, ... More
Superposition of fundamental solutions of second order quasilinear equationsOct 04 2016We prove a superposition principle in the spirit of Crandall-Zhang and Lindqvist-Manfredi for a class of second order quasilinear equations. Riesz potentials of nonnegative and compactly supported continuous functions are either subsolutions or supersolutions ... More
Oka properties of ball complementsMar 09 2013Mar 29 2017Let $n>1$ be an integer. We prove that holomorphic maps from Stein manifolds $X$ of dimension $<n$ to the complement $\mathbb{C}^n\setminus L$ of a compact convex set $L\subset\mathbb{C}^n$ satisfy the basic Oka property with approximation and interpolation. ... More
Riesz potentials and p-superharmonic functions in Lie groups of Heisenberg typeMay 21 2010We prove a superposition principle for Riesz potentials of nonnegative continuous functions on Lie groups of Heisenberg type. More precisely, we show that the Riesz potential $$ R_\alpha(\rho)(g) = \int_{\G} N(g^{-1} g')^{\alpha-Q} \rho(g') dg', \qquad ... More
Oka properties of ball complementsMar 09 2013Jun 09 2015Let $n>1$ be an integer. We prove that holomorphic maps from Stein manifolds $X$ of dimension $<n$ to the complement $\mathbb{C}^n\setminus L$ of a compact convex set $L\subset\mathbb{C}^n$ satisfy the basic Oka property with approximation and interpolation. ... More
Adaptive Mesh BooleansMay 05 2016We present a new method for performing Boolean operations on volumes represented as triangle meshes. In contrast to existing methods which treat meshes as 3D polyhedra and try to partition the faces at their exact intersection curves, we treat meshes ... More
The Case for Deep, Wide-Field CosmologyFeb 16 2009Feb 16 2009Much of the science case for the next generation of deep, wide-field optical/infrared surveys has been driven by the further study of dark energy. This is a laudable goal (and the subject of a companion white paper by Zhan et al.). However, one of the ... More
Nature of the Structural Symmetries Associated with Hybrid Improper Ferroelectricity in Ca3X2O7Mar 18 2019In hybrid improper ferroelectric systems, polarization arises from the onset of successive nonpolar lattice modes. In this work, measurements and modeling were performed to determine the spatial symmetries of the phases involved in the transitions to ... More
Science-Driven Optimization of the LSST Observing StrategyAug 14 2017The Large Synoptic Survey Telescope is designed to provide an unprecedented optical imaging dataset that will support investigations of our Solar System, Galaxy and Universe, across half the sky and over ten years of repeated observation. However, exactly ... More
Rare and Radiative Kaon DecaysMar 04 1993We review the status of theory and experiment of very rare and forbidden kaon decays. We then review the radiative non-leptonic decays, and the associated Dalitz pair modes. We pay particular attention to the study of long distance physics in radiative ... More
Comparison of Domain Nucleation Mechanisms in a Minimal Model of Shoot Apical MeristemApr 15 2016Apr 19 2016Existing mathematical models of the shoot apical meristem (SAM) explain nucleation and confinement of a stem cell domain by Turing's mechanism, assuming that the diffusion coefficients of the activator (WUSCHEL) and inhibitor (CLAVATA) are significantly ... More
Turbulence near cyclic fold bifurcations in birhythmic mediaFeb 24 2004We show that at the onset of a cyclic fold bifurcation, a birhythmic medium composed of glycolytic oscillators displays turbulent dynamics. By computing the largest Lyapunov exponent, the spatial correlation function, and the average transient lifetime, ... More
Measurement of the Mass Profile of Abell 1689Apr 01 1995Apr 03 1995In this letter we present calibrated mass and light profiles of the rich cluster of galaxies Abell 1689 out to 1 $h^{-1}$ Mpc from the center. The high surface density of faint blue galaxies at high redshift, selected by their low surface brightness, ... More
Quantum compilation and circuit optimisation via energy dissipationNov 07 2018Dec 19 2018We describe a method for automatically recompiling a quantum circuit A into a target circuit B, with the goal that both circuits have the same action on a specific input i.e. A|in> = B|in>. This is of particular relevance to hybrid, NISQ-era algorithms ... More
Marstrand's density theorem in the Heisenberg groupJul 24 2014We prove that if $\mu$ is a Radon measure on the Heisenberg group $\mathbb{H}^n$ such that the density $\Theta^s(\mu,\cdot)$, computed with respect to the Kor\'anyi metric $d_H$, exists and is positive and finite on a set of positive $\mu$ measure, then ... More
Bifurcation analysis of a model of the budding yeast cell cycleApr 05 2004We study the bifurcations of a set of nine nonlinear ordinary differential equations that describe the regulation of the cyclin-dependent kinase that triggers DNA synthesis and mitosis in the budding yeast, Saccharomyces cerevisiae. We show that Clb2-dependent ... More
The Mass distribution of the Most Luminous X-ray Cluster RXJ1347.5-1145 from Gravitational LensingMar 28 1997Galaxy cluster mass distribution are potentially useful probes of $\Omega_0$ and the nature of the dark matter. Large clusters will distort the observed shapes of background galaxies through gravitational lensing allowing the measurement of the cluster ... More
An unbiased metric of antiproliferative drug effect in vitroMay 22 2016In vitro cell proliferation assays are widely used in pharmacology, molecular biology, and drug discovery. Using theoretical modeling and experimentation, we show that current antiproliferative drug effect metrics suffer from time-dependent bias, leading ... More
Measurements and ab initio Molecular Dynamics Simulations of the High Temperature Ferroelectric Transition in Hexagonal RMnO3Oct 08 2011Measurements of the structure of hexagonal RMnO3 (R=rare earths (Ho) and Y) for temperatures significantly above the ferroelectric transition temperature (TFE) were conducted to determine the nature of the transition. The local and long range structural ... More
High Pressure Structural Stability of Multiferroic Hexagonal REMnO3Oct 04 2010May 03 2011Structural changes in REMnO3 (RE= Y, Ho, Lu) under high pressure were examined by synchrotron x-ray diffraction methods at room temperature. Compression occurs more readily in the ab plane than along the c-axis. Under hydrostatic pressure (~11 GPa), the ... More
Removable sets for homogeneous linear PDE in Carnot groupsMay 23 2013Let $\cL$ be a homogeneous left invariant differential operator on a Carnot group. Assume that both $\cL$ and $\cL^t$ are hypoelliptic. We study the removable sets for $\cL$-solutions. We give precise conditions in terms of the Carnot--Carath\'eodory ... More
Pressure Effects on the Atomic and Electronic Structure of Aligned Small Diameter Carbon NanotubesMay 05 2008Aug 27 2008Density functional methods have been used to calculate the electronic properties of aligned smalldiameter single-walled carbon nanotubes under hydrostatic pressures. Abrupt pressure induced semiconductor-metal and metal-semiconductor transitions concomitant ... More
Pressure effects on charge, spin, and metal-insulator transitions in narrow bandwidth manganite Pr$_{1-x}$Ca$_{x}$MnO$_{3}$Nov 19 2003Dec 03 2003Pressure effects on the charge and spin states and the relation between the ferromagnetic and metallic states were explored on the small bandwidth manganite Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ (x = 0.25, 0.3, 0.35). Under pressure, the charge ordering state is ... More
Correlations between pressure and bandwidth effects in metal-insulator transitions in manganitesOct 29 2003The effect of pressure on the metal-insulator transition in manganites with a broad range of bandwidths is investigated. A critical pressure is found at which the metal-insulator transition temperature, T$_{MI}$, reaches a maximum value in every sample ... More
Pressure Induced Reentrant Electronic and Magnetic State in Pr0.7Ca0.3MnO3 ManganiteJan 23 2003Sep 30 2003In Pr$_{0.7}$Ca$_{0.3}$MnO$_{3}$, pressure induces reentrant magnetic and electronic state changes in the range 1 atm to $\sim$ 6 GPa. The metal-insulator and magnetic transition temperatures coincide from $\sim$1 to 5 GPa, decouple outside of this range ... More
Temperature Dependent Local Structure of LaFeAsO_{1-x}F_x: Probing the Bond CorrelationsMar 24 2009The local structure of the parent and doped LaFeAsO1-xFx (pnictide) compounds were studied by x-ray absorption spectroscopy. In the doped system, the Fe-As and Fe-Fe correlations are well modeled by an Einstein model with no low temperature anomalies. ... More
eLISA: Astrophysics and cosmology in the millihertz regimeJan 17 2012This document introduces the exciting and fundamentally new science and astronomy that the European New Gravitational Wave Observatory (NGO) mission (derived from the previous LISA proposal) will deliver. The mission (which we will refer to by its informal ... More
The decays $K \to ππν\overlineν$ within the standard modelDec 23 1995Oct 15 1996We study the reactions $K \rightarrow \pi \pi \nu \overline{\nu}$ within the minimal standard model. We use isospin symmetry to relate the matrix elements to the form factors measured in $K_{\ell 4}$. We argue that these modes are short distance dominated ... More
Implications of Improved Upper Bounds on $|ΔL|=2$ ProcessesMay 29 2000Aug 30 2000We discuss implications of improved upper bounds on the $|\Delta L|=2$ processes (i) $K^+ \to \pi^- \mu^+ \mu^+$, from an experiment at BNL, and (ii) $\mu^- \to e^+$ conversion, from an experiment at PSI. In particular, we address the issue of constraints ... More
Charting an Intent Driven NetworkApr 20 2016The current strong divide between applications and the network control plane is desirable for many reasons; but a downside is that the network is kept in the dark regarding the ultimate purposes and intentions of applications and, as a result, is unable ... More