Results for "A. D. Howard"

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Ferreting out the Fluffy Bunnies: Entanglement constrained by Generalized superselection rulesSep 04 2003Entanglement is a resource central to quantum information (QI). In particular, entanglement shared between two distant parties allows them to do certain tasks that would otherwise be impossible. In this context, we study the effect on the available entanglement ... More
Three-dimensional flows in slowly-varying planar geometriesJun 23 2003Nov 06 2003We consider laminar flow in channels constrained geometrically to remain between two parallel planes; this geometry is typical of microchannels obtained with a single step by current microfabrication techniques. For pressure-driven Stokes flow in this ... More
Disconnecting Solar Magnetic FluxNov 30 2011Disconnection of open magnetic flux by reconnection is required to balance the injection of open flux by CMEs and other eruptive events. Making use of recent advances in heliospheric background subtraction, we have imaged many abrupt disconnection events. ... More
Quantum phenomena modelled by interactions between many classical worldsFeb 25 2014Oct 26 2014We investigate whether quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but finite, number of classical 'worlds', and quantum effects arise solely from a universal interaction between these worlds, ... More
Maximum-entropy Surrogation in Network Signal DetectionFeb 29 2012Multiple-channel detection is considered in the context of a sensor network where raw data are shared only by nodes that have a common edge in the network graph. Established multiple-channel detectors, such as those based on generalized coherence or multiple ... More
Inbound waves in the solar corona: a direct indicator of Alfvén Surface locationApr 11 2014Apr 15 2014The tenuous supersonic solar wind that streams from the top of the corona passes through a natural boundary -- the Alfv\'en surface -- that marks the causal disconnection of individual packets of plasma and magnetic flux from the Sun itself. The Alfv\'en ... More
Doppler Resilient Waveforms with Perfect AutocorrelationMar 12 2007We describe a method of constructing a sequence of phase coded waveforms with perfect autocorrelation in the presence of Doppler shift. The constituent waveforms are Golay complementary pairs which have perfect autocorrelation at zero Doppler but are ... More
Wetting of crossed fibers: multiple steady states and symmetry breakingMar 05 2014We investigate the wetting properties of the simplest element of an array of random fibers: two rigid fibers crossing with an inclination angle and in contact with a droplet of a perfectly wetting liquid. We show experimentally that the liquid adopts ... More
Quarkonium spin structure in lattice NRQCDNov 25 1996Numerical simulations of the quarkonium spin splittings are done in the framework of lattice nonrelativistic quantum chromodynamics (NRQCD). At leading order in the velocity expansion the spin splittings are of $O(M_Q v^4)$, where $M_Q$ is the renormalized ... More
An upper bound on $P$-wave charmonium production via the color-octet mechanismNov 11 1993A factorization theorem for $P$-wave quarkonium production, recently derived by Bodwin, Braaten, Yuan and Lepage, is applied to $\Upsilon \to \chi_{cJ} + X$, where $\chi_{cJ}$ labels the ${}^3 P_J$ charmonium states. The widths for $\chi_{cJ}$ production ... More
On the Origin of Narrow, Very Long, Straight Jets from Some Newly Forming StarsApr 29 1997Observations have shown the existence of narrow, very long, straight jets emitted by some newly forming stars (1). It is highly likely that stars forming in the plane of a spiral galaxy do so in the presence of an almost uniform magnetic field. In the ... More
Adjoint ``Quarks'' and the Physics of ConfinementNov 04 1995The quark-antiquark potential and the chromoelectric fields generated by ``quarks'' in the adjoint representation of SU(2) color are analyzed in the scaling region of the theory. New results with interesting implications for our understanding of the confinement ... More
Improvement, dynamical fermions, and heavy quark screening in QCD_3Sep 29 1998First results from simulations of improved actions for both gauge fields and staggered fermion fields in three dimensional QCD are presented. This work provides insight into some issues of relevance to lattice theories in four dimensions. In particular, ... More
Higher-order perturbation theory for highly-improved actionsOct 16 2003Oct 21 2003I review techniques and applications of higher-order perturbation theory for highly-improved lattice actions.
ADJOINT "QUARK" COLOR FIELDS IN FOUR-DIMENSIONAL LATTICE GAUGE THEORY: VACUUM SCREENING AND PENETRATIONMar 15 1995The fields generated by ``quarks'' in the adjoint representation of SU(2) color are analyzed in the scaling region of the four-dimensional lattice theory. Evidence of vacuum screening of adjoint quarks is obtained from a comparison of quark-antiquark ... More
$Υ$ decay into charmonium and the color octet mechanismJul 21 1993A factorization theorem for $P$-wave quarkonium production, recently derived by Bodwin, Braaten, Yuan and Lepage, is applied to $\Upsilon \to \chi_{cJ} + X$, where $\chi_{cJ}$ labels the ${}^3 P_J$ charmonium states. The widths for $\chi_{cJ}$ production ... More
Photon Acceleration in a Flying FocusApr 30 2019A high-intensity laser pulse propagating through a medium triggers an ionization front that can accelerate and frequency-upshift the photons of a second pulse. The maximum upshift is ultimately limited by the accelerated photons outpacing the ionization ... More
J plots: a new method for characterizing structures in the interstellar mediumMar 05 2018Large scale surveys have brought about a revolution in astronomy. To analyse the resulting wealth of data, we need automated tools to identify, classify, and quantify the important underlying structures. We present here a method for classifying and quantifying ... More
Challenges in Affecting U.S. Attitudes Towards Space ScienceAug 25 2000Space Science enjoys broad public support in the US. People say they follow developments with interest, and that the programs are worth their cost. This attitude seems to arise in part because of the intrinsic accessibility and appeal of the subject matter. ... More
Convective dispersion without molecular diffusionJan 09 2003A method-of-moments scheme is invoked to compute the asymptotic, long-time mean (or composite) velocity and dispersivity (effective diffusivity) of a two-state particle undergoing one-dimensional convective-diffusive motion accompanied by a reversible ... More
Trilepton Higgs signal at hadron collidersOct 15 1997Determining the origin of electroweak symmetry breaking will be one of the primary functions of high energy colliders. We point out that most Higgs boson searches pursued at hadron colliders require Yukawa interactions either in the production or the ... More
Unveiling the nature of the unidentified gamma-ray sourcesMar 13 2013One of the main scientific objectives of the recent Fermi mission is investigating the origin of the unidentified gamma-ray sources (UGSs). Despite the large improvements of Fermi in the gamma-ray source localization with respect to the past gamma-ray ... More
The Molecular Gas-Star Formation Connection in an Optically-Selected Sample of Interacting GalaxiesNov 10 1999We have obtained CO(1-0) observations for a sample of 37 interacting galaxy systems, chosen from a parent sample of optically-selected interacting galaxies. The sample observed here spans a large range of interaction strengths and star formation rates ... More
An analysis of the FIR/RADIO Continuum Correlation in the Small Magellanic CloudSep 01 2012The local correlation between far-infrared (FIR) emission and radio-continuum (RC) emission for the Small Magellanic Cloud (SMC) is investigated over scales from 3 kpc to 0.01 kpc. Here, we report good FIR/RC correlation down to ~15 pc. The reciprocal ... More
A Coronal Hole's Effects on CME Shock Morphology in the Inner HeliosphereJun 15 2012We use STEREO imagery to study the morphology of a shock driven by a fast coronal mass ejection (CME) launched from the Sun on 2011 March 7. The source region of the CME is located just to the east of a coronal hole. The CME ejecta is deflected away from ... More
Identification of New Gamma-Ray Blazar Candidates With Multifrequency Archival ObservationsAug 08 2013Blazars are a highly-variable, radio-loud subclass of active galactic nuclei (AGN). In order to better understand such objects we must be able to easily identify candidate blazars from the growing population of unidentified sources. Working towards this ... More
Pattern formation inside bacteria: fluctuations due to low copy number of proteinsFeb 20 2003We examine fluctuation effects due to the low copy number of proteins involved in pattern-forming dynamics within a bacterium. We focus on a stochastic model of the oscillating MinCDE protein system regulating accurate cell division in E. coli. We find ... More
Variable selection via penalized credible regions with Dirichlet-Laplace global-local shrinkage priorsFeb 03 2016Aug 31 2016The method of Bayesian variable selection via penalized credible regions separates model fitting and variable selection. The idea is to search for the sparsest solution within the joint posterior credible regions. Although the approach was successful, ... More
Technicolor with a Massless Scalar DoubletAug 02 1993We consider a minimal technicolor model in which the ordinary and technicolor sectors are coupled by a {\it massless} scalar doublet. When technicolor interactions become strong, the resulting technicolor condensate not only breaks the electroweak symmetry, ... More
Fine-tuning favors mixed axion/axino cold dark matter over neutralinos in the minimal supergravity modelOct 02 2009May 21 2010Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter space, there is a large overabundance of neutralino cold dark matter (CDM). We find that the allowed regions of mSUGRA parameter space which match the measured abundance of CDM ... More
Adjoint "quarks" on coarse anisotropic lattices: Implications for string breaking in full QCDJan 19 2000A detailed study is made of four dimensional SU(2) gauge theory with static adjoint ``quarks'' in the context of string breaking. A tadpole-improved action is used to do simulations on lattices with coarse spatial spacings $a_s$, allowing the static potential ... More
Pennants for DescriptorsOct 14 2013We present a new technique (called pennants) for displaying the descriptors related to a descriptor across literatures, rather in a thesaurus. It has definite implications for online searching and browsing. Pennants, named for the flag they resemble, ... More
The limitations of model-based experimental design and parameter estimation in sloppy systemsFeb 16 2016Jun 14 2016We explore the relationship among model fidelity, experimental design, and parameter estimation in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex ... More
Identification of the infrared non-thermal emission in BlazarsMar 01 2012Blazars constitute the most interesting and enigmatic class of extragalactic gamma-ray sources dominated by non-thermal emission. In this Letter, we show how the WISE infrared data make possible to identify a distinct region of the [3.4]-[4.6]-[12] micron ... More
Optical Imaging of Very Luminous Infrared Galaxy Systems: Photometric Properties and Late EvolutionFeb 16 2004A sample of 19 low redshift (0.03$<$z$<$0.07) very luminous infrared galaxy (VLIRG: $10^{11}L_\odot< $ L[8-1000 $\mu$m] $ < 10^{12} L_\odot$) systems (30 galaxies) has been imaged in $B$, $V$, and $I$. These objects cover a luminosity range that is key ... More
Highly Improved Naive and Staggered FermionsOct 16 2001We present a new action for highly improved staggered fermions. We show that perturbative calculations for the new action are well-behaved where those of the conventional staggered action are badly behaved. We discuss the effects of the new terms in controlling ... More
Evolutionary Analysis of Gaseous Sub-Neptune-Mass Planets with MESAMar 21 2016Oct 06 2016Sub-Neptune-sized exoplanets represent one of the most common types of planets in the Milky Way, yet many of their properties are unknown. Here, we present a prescription to adapt the capabilities of the stellar evolution toolkit Modules for Experiments ... More
Hubble Space Telescope Spectroscopy of the Balmer lines in Sirius BJun 24 2005Sirius B is the nearest and brightest of all white dwarfs, but it is very difficult to observe at visible wavelengths due to the overwhelming scattered light contribution from Sirius A. However, from space we can take advantage of the superb spatial resolution ... More
Comprehensive Observations of a Solar Minimum CME with STEREONov 19 2008We perform the first kinematic analysis of a CME observed by both imaging and in situ instruments on board STEREO, namely the SECCHI, PLASTIC, and IMPACT experiments. Launched on 2008 February 4, the CME is tracked continuously from initiation to 1 AU ... More
The influence of van der Waals interactions on a bubble moving in a tubeJan 05 2016Oct 24 2016We consider the unsteady thin-film dynamics of a long bubble of negligible viscosity that advances at a uniform speed in a cylindrical capillary tube. The bubble displaces a viscous, nonwetting fluid, creating a thin film between its interface and the ... More
Curvature suppresses the Rayleigh-Taylor instabilityJan 17 2014Jan 20 2014The dynamics of a thin liquid film on the underside of a curved cylindrical substrate is studied. The evolution of the liquid layer is investigated as the film thickness and the radius of curvature of the substrate are varied. A dimensionless parameter ... More
The influence of van der Waals interactions on a bubble moving in a tubeJan 05 2016We consider the unsteady thin-film dynamics of a long bubble of negligible viscosity that advances at a uniform speed in a cylindrical capillary tube. The bubble displaces a viscous non-wetting fluid, creating a thin film between its interface and the ... More
Radio Weak BL Lac objects in the Fermi eraJan 21 2017The existence of "radio weak BL Lac objects" (RWBLs) has been an open question, still unsolved, since the discovery that quasars could be radio-quiet or radio-loud. Recently several groups identified RWBL candidates, mostly found while searching for low ... More
Correlation between microstructure and magnetotransport in organic semiconductor spin valve structuresOct 01 2008Dec 18 2008We have studied magnetotransport in organic-inorganic hybrid multilayer junctions. In these devices, the organic semiconductor (OSC) Alq$_3$ (tris(8-hydroxyquinoline) aluminum) formed a spacer layer between ferromagnetic (FM) Co and Fe layers. The thickness ... More
The Oblique Orbit of the Super-Neptune HAT-P-11bSep 28 2010We find the orbit of the Neptune-sized exoplanet HAT-P-11b to be highly inclined relative to the equatorial plane of its host star. This conclusion is based on spectroscopic observations of two transits, which allowed the Rossiter-McLaughlin effect to ... More
Role of the membrane for mechanosensing by tethered channelsMar 18 2016Biologically important membrane channels are gated by force at attached tethers. Here, we generically characterize the non-trivial interplay of force, membrane tension, and channel deformations that can affect gating. A central finding is that minute ... More
Characteristic lengths at moving contact lines for a perfectly wetting fluid: the influence of speed on the dynamic contact angleOct 24 2002It is common to relate the dynamic contact angle $\theta_d$ to the relative speed between the substrate and the contact line; theory suggests $\theta_d^3 \propto U$. In fact, available physical models show that the dynamic angle involves speed logarithmically ... More
Role of the membrane for mechanosensing by tethered channelsMar 18 2016Jul 27 2017Biologically important membrane channels are gated by force at attached tethers. Here, we generically characterize the non-trivial interplay of force, membrane tension, and channel deformations that can affect gating. A central finding is that minute ... More
The California-Kepler Survey. IV. Metal-rich Stars Host a Greater Diversity of PlanetsDec 11 2017Jan 21 2018Probing the connection between a star's metallicity and the presence and properties of any associated planets offers an observational link between conditions during the epoch of planet formation and mature planetary systems. We explore this connection ... More
Optical spectroscopic observations of gamma-ray blazar candidates II. The 2013 KPNO campaign in the Northern HemisphereMar 13 2015We recently started a systematic search of low-energy counterparts of the unidentified gamma-ray sources (UGSs) listed in the Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) and the Fermi-LAT 2-Year Source Catalog (2FGL).} The main goal of ... More
Self-crumpling elastomers: bending induced by the drying stimulus of a nanoparticle suspensionSep 24 2014We report an experimental study of the drying-induced peeling of a bilayer, consisting of an elastomeric disk coated with a suspension of nanoparticles. We show that although capillary forces associated with the scale of the droplet can not compete with ... More
Teichmuller Space is Not Gromov HyperbolicJul 01 1994We prove that the Teichmuller Space of Riemann Surfaces of genus g>1, equipped with the Teichmuller metric, is not a Gromov Hyperbolic space.
A Cellular Automaton Model for Bi-Directionnal TrafficJan 05 1998We investigate a cellular automaton (CA) model of traffic on a bi-directional two-lane road. Our model is an extension of the one-lane CA model of {Nagel and Schreckenberg 1992}, modified to account for interactions mediated by passing, and for a distribution ... More
Relaxation time of the topological T1 process in a two-dimensional foamAug 18 2006The elementary topological T1 process in a two-dimensional foam corresponds to the "flip" of one soap film with respect to the geometrical constraints. From a mechanical point of view, this T1 process is an elementary relaxation process through which ... More
Comparison of Energies Between Eruptive Phenomena and Magnetic Field in AR 10930Oct 28 2010We present a study comparing the energy carried away by a coronal mass ejection (CME) and the radiative energy loss in associated flare plasma, with the decrease in magnetic free energy during a release in active region NOAA 10930 on December 13, 2006 ... More
Phonons and superconductivity in YbC$_6$ and related compoundsSep 15 2010The out-of-plane intercalate phonons of superconducting YbC6 have been measured with inelastic x-ray scattering. Model fits to this data, and previously measured out-of-plane intercalate phonons in graphite intercalation compounds (GICs), reveal surprising ... More
Precise Radial Velocities of 2046 Nearby FGKM Stars and 131 StandardsJul 26 2012Aug 01 2012We present radial velocities with an accuracy of 0.1 km/s for 2046 stars of spectral type F,G,K, and M, based on 29000 spectra taken with the Keck I telescope. We also present 131 FGKM standard stars, all of which exhibit constant radial velocity for ... More
A Correlation Between Stellar Activity and Hot Jupiter Emission SpectraApr 15 2010Jul 22 2010We present evidence for a correlation between the observed properties of hot Jupiter emission spectra and the activity levels of the host stars measured using Ca II H & K emission lines. We find that planets with dayside emission spectra that are well-described ... More
The WISE gamma-ray strip parametrization: the nature of the gamma-ray Active Galactic Nuclei of Uncertain typeMar 06 2012Despite the large number of discoveries made recently by Fermi, the origins of the so called unidentified gamma-ray sources remain unknown. The large number of these sources suggests that among them there could be a population that significantly contributes ... More
Ground State Quantum Coherences: from Quantum Beats to Strong ControlJan 14 2014Second order correlations reveal quantum beats from a coherent ground-state superposition on the undriven mode of a two-mode cavity QED system. Continuous drive induces decoherence due to Rayleigh scattering. We control this with feedback and explore ... More
Unveiling the nature of the unidentified gamma-ray sources V: analysis of the radio candidates with the kernel density estimationApr 23 2014Nearly one-third of the gamma-ray sources detected by Fermi are still unidentified, despite significant recent progress in this effort. On the other hand, all the gamma-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio ... More
Unveiling the nature of the unidentified gamma-ray sources II: radio, infrared and optical counterparts of the gamma-ray blazar candidatesMar 14 2013A significant fraction (~30%) of the high-energy gamma-ray sources listed in the second Fermi LAT catalog (2FGL) are still of unknown origin, being not yet associated with counterparts at low energies. We recently developed a new association method to ... More
The Frequency of Hot Jupiters Orbiting Nearby Solar-Type StarsMay 10 2012We determine the fraction of F, G, and K dwarfs in the Solar Neighborhood hosting hot jupiters as measured by the California Planet Survey from the Lick and Keck planet searches. We find the rate to be 1.2\pm0.38%, which is consistent with the rate reported ... More
Exploring confinement by cooling: A study of compact QED$_3$May 21 1993The role of monopoles in the confining behavior of compact lattice $QED_3$ is studied using an adiabatic cooling method. Monopole-antimonopole pairs with large separation suvive cooling and the presence or absence of such plasma monopoles provides a useful ... More
Static Potential and Local Color Fields in Unquenched Three-Dimensional Lattice QCDSep 03 2002String breaking by dynamical quarks in (2+1)-d lattice QCD is demonstrated in this project, by measuring the static potential and the local color-electric field strength between a heavy quark and antiquark pair at large separations. Simulations are done ... More
Tadpole-improved SU(2) lattice gauge theoryMar 26 1998Apr 09 1998A comprehensive analysis of tadpole-improved SU(2) lattice gauge theory is made. Simulations are done on isotropic and anisotropic lattices, with and without improvement. Two tadpole renormalization schemes are employed, one using average plaquettes, ... More
Exploring Lattice Quantum Chromodynamics by CoolingSep 13 1994The effect of cooling on a number of observables is calculated in SU(2) lattice gauge theory. The static quark-antiquark potential and spin-dependent interactions are studied, and the topological charge is monitored. The chiral symmetry breaking order ... More
Neutralino versus axion/axino cold dark matter in the 19 parameter SUGRA modelMay 12 2010Sep 15 2010We calculate the relic abundance of thermally produced neutralino cold dark matter in the general 19 parameter supergravity (SUGRA-19) model. A scan over GUT scale parameters reveals that models with a bino-like neutralino typically give rise to a dark ... More
Mainly axion cold dark matter in the minimal supergravity modelJun 15 2009Aug 12 2009We examine the minimal supergravity (mSUGRA) model under the assumption that the strong CP problem is solved by the Peccei-Quinn mechanism. In this case, the relic dark matter (DM) abundance consists of three components: {\it i}). cold axions, {\it ii}). ... More
Static potential and local color fields in unquenched lattice QCD$_3$Aug 18 2004String breaking by dynamical quarks in three-dimensional lattice QCD is analyzed through measurements of the potential and the local color-electric field strength generated by a static quark-antiquark pair. Simulations were done for unquenched SU(2) color ... More
The California-Kepler Survey. II. Precise Physical Properties of 2025 Kepler Planets and Their Host StarsMar 30 2017Jun 16 2017We present stellar and planetary properties for 1305 Kepler Objects of Interest (KOIs) hosting 2025 planet candidates observed as part of the California-Kepler Survey. We combine spectroscopic constraints, presented in Paper I, with stellar interior modeling ... More
Perturbative coefficients for improved actions by Monte Carlo at large $β$Oct 02 1997Perturbative estimates of operator coefficients for improved lattice actions are becoming increasingly important for precision simulations of many hadronic observables. Following previous work by Dimm, Lepage, and Mackenzie, we consider the feasibility ... More
Flux-tubes in three-dimensional lattice gauge theoriesMar 17 1993Flux-tubes in different representations of SU(2) and U(1) lattice gauge theories in three dimensions are measured. Wilson loops generate heavy ``quark-antiquark'' pairs in fundamental ($j=1/2$), adjoint ($j=1$), and quartet ($j=3/2$) representations of ... More
On the screening of the potential between adjoint sources in $QCD_3$Dec 08 1994We calculate the potential between adjoint sources in $SU(2)$ pure gauge theory in three dimensions. We investigate whether the potential saturates at large separations due to the creation of a pair of gluelumps, colour-singlet states formed when glue ... More
Straight Line Orbits in Hamiltonian FlowsMar 28 2009We investigate periodic straight-line orbits (SLO) in Hamiltonian force fields using both direct and inverse methods. A general theorem is proven for natural Hamiltonians quadratic in the momenta in arbitrary dimension and specialized to two and three ... More
An Information-geometric Approach to Sensor ManagementFeb 29 2012An information-geometric approach to sensor management is introduced that is based on following geodesic curves in a manifold of possible sensor configurations. This perspective arises by observing that, given a parameter estimation problem to be addressed ... More
``GLUELUMP'' SPECTRUM AND ADJOINT SOURCE POTENTIAL IN LATTICE QCD$_3$Apr 21 1995We calculate the potential between ``quarks'' which are in the adjoint representation of SU(2) color in the three-dimensional lattice theory. We work in the scaling region of the theory and at large quark separations $R$. We also calculate the masses ... More
The Savvidy ``ferromagnetic vacuum'' in three-dimensional lattice gauge theoryOct 23 1992The vacuum effective potential of three-dimensional SU(2) lattice gauge theory in an applied color-magnetic field is computed over a wide range of field strengths. The background field is induced by an external current, as in continuum field theory. Scaling ... More
Hard supersymmetry-breaking "wrong-Higgs" couplings of the MSSMNov 19 2007Jun 10 2008In the minimal supersymmetric extension of the Standard Model (MSSM), if the two Higgs doublets are lighter than some subset of the superpartners of the Standard Model particles, then it is possible to integrate out the heavy states to obtain an effective ... More
The Red-Sequence Cluster Survey I: The Survey and Cluster Catalogs for Patches RCS0926+37 and RCS1327+29Nov 02 2004The Red-Sequence Cluster Survey (RCS) is a $\sim$100 square degree, two-filter imaging survey in the $R_C$ and $z'$ filters, designed primarily to locate and characterise galaxy clusters to redshifts as high as $z=1.4$. This paper provides a detailed ... More
Mean link versus average plaquette tadpoles in lattice NRQCDSep 15 1998We compare mean-link and average plaquette tadpole renormalization schemes in the context of the quarkonium hyperfine splittings in lattice NRQCD. Simulations are done for the three quarkonium systems $c\bar c$, $b\bar c$, and $b\bar b$. The hyperfine ... More
Tadpole renormalization and relativistic corrections in lattice NRQCDFeb 27 1998Mar 09 1998We make a comparison of two tadpole renormalization schemes in the context of the quarkonium hyperfine splittings in lattice NRQCD. Improved gauge-field and NRQCD actions are analyzed using the mean-link $u_{0,L}$ in Landau gauge, and using the fourth ... More
Geodesics and Spanning Trees for Euclidean First-Passage PercolationOct 21 2000The metric $D_\alpha (q,q')$ on the set $Q$ of particle locations of a homogeneous Poisson process on $R^d$, defined as the infimum of $(\sum_i |q_i - q_{i+1}|^\alpha)^{1/\alpha}$ over sequences in $Q$ starting with $q$ and ending with $q'$ (where $| ... More
The uniform general signed rank test and its design sensitivityApr 18 2019A sensitivity analysis in an observational study tests whether the qualitative conclusions of an analysis would change if we were to allow for the possibility of limited bias due to confounding. The design sensitivity of a hypothesis test quantifies the ... More
HAT-P-11: Discovery of a Second Planet and a Clue to Understanding Exoplanet ObliquitiesMay 23 2018HAT-P-11 is a mid-K dwarf that hosts one of the first Neptune-sized planets found outside the solar system. The orbit of HAT-P-11b is misaligned with the star's spin --- one of the few known cases of a misaligned planet orbiting a star less massive than ... More
Optical spectroscopic observations of gamma-ray blazar candidates IV. Results of the 2014 follow-up campaignMar 17 2015The extragalactic gamma-ray sky is dominated by the emission arising from blazars, one of the most peculiar classes of radio-loud active galaxies. Since the launch of Fermi several methods were developed to search for blazars as potential counterparts ... More
The California-Kepler Survey. III. A Gap in the Radius Distribution of Small PlanetsMar 30 2017Jun 16 2017The size of a planet is an observable property directly connected to the physics of its formation and evolution. We used precise radius measurements from the California-Kepler Survey (CKS) to study the size distribution of 2025 $\textit{Kepler}$ planets ... More
The California-Kepler Survey V. Peas in a Pod: Planets in a Kepler Multi-planet System are Similar in Size and Regularly SpacedJun 19 2017Feb 07 2018We have established precise planet radii, semimajor axes, incident stellar fluxes, and stellar masses for 909 planets in 355 multi-planet systems discovered by Kepler. In this sample, we find that planets within a single multi-planet system have correlated ... More
Some Nearly Quantum TheoriesJul 22 2015Nov 06 2015We consider possible non-signaling composites of probabilistic models based on euclidean Jordan algebras. Subject to some reasonable constraints, we show that no such composite exists having the exceptional Jordan algebra as a direct summand. We then ... More
Coffee-stain growth dynamics on dry and wet surfacesNov 23 2016The drying of a drop containing particles often results in the accumulation of the particles at the contact line. In this work, we investigate the drying of an aqueous colloidal drop surrounded by a hydrogel that is also evaporating. We combine theoretical ... More
Microwave Anisotropies from Texture Seeded Structure FormationNov 17 1993The cosmic microwave anisotropies in a scenario of large scale structure formation with cold dark matter and texture are discussed and compared with recent observational results of the COBE satellite. A couple of important statistical parameters are determined. ... More
Source-like solution for radial imbibition into a homogeneous semi-infinite porous mediumFeb 16 2012We describe the imbibition process from a point source into a homogeneous semi-infinite porous material. When body forces are negligible, the advance of the wetting front is driven by capillary pressure and resisted by viscous forces. With the assumption ... More
Non-Fickian macroscopic model of axial diffusion of granular materials in a long cylindrical tumblerJan 30 2019We formulate and solve a non-Fickian macroscopic model of axial diffusion of a granular material in a finite cylindrical tumbler. The model accounts for localization of shear and, thus, diffusion induced by particle collisions in a thin surface flowing ... More
Shear dispersion in dense granular flowsFeb 27 2014We formulate and solve a model problem of dispersion of dense granular materials in rapid shear flow down an incline. The effective dispersivity of the depth-averaged concentration of the dispersing powder is shown to vary as the P\'eclet number squared, ... More
Liquid acrobaticsOct 09 2008We experiment with injecting a continuous stream of gas into a shallow liquid, similar to how one might blow into a straw placed at the bottom of a near-empty drink. By varying the angle of the straw (here a metal needle), we observe a variety of dynamics, ... More
Solution of the inverse scattering problem by T-matrix completion. II. SimulationsMay 25 2015Sep 27 2016This is Part II of the paper series on data-compatible T-matrix completion (DCTMC), which is a method for solving nonlinear inverse problems. Part I of the series contains theory and here we present simulations for inverse scattering of scalar waves. ... More
Geometry of the complex of curves II: Hierarchical structureJul 27 1998This paper continues a geometric study of Harvey's Complex of Curves, whose ultimate goal is to apply the theory of hyperbolic spaces and groups to algorithmic questions for the Mapping Class Group and geometric properties of Kleinian representations. ... More
Efficient fitting of multiplanet Keplerian models to radial velocity and astrometry dataApr 23 2009Apr 24 2009We describe a technique for solving for the orbital elements of multiple planets from radial velocity (RV) and/or astrometric data taken with 1 m/s and microarcsecond precision, appropriate for efforts to detect Earth-massed planets in their stars' habitable ... More
Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani BSep 01 2017The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD's mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low ... More
On $(2,4)$ complete intersection threefolds that contain an Enriques surfaceOct 06 2012Aug 01 2013We study nodal complete intersection threefolds of type $(2,4)$ in $\PP^5$ which contain an Enriques surface in its Fano embedding. We completely determine Calabi-Yau birational models of a generic such threefold. These models have Hodge numbers $(h^{11},h^{12})=(2,32)$. ... More