Results for "John P. Chiverton"

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Multi-View Region Adaptive Multi-temporal DMM and RGB Action RecognitionApr 12 2019Human action recognition remains an important yet challenging task. This work proposes a novel action recognition system. It uses a novel Multiple View Region Adaptive Multi-resolution in time Depth Motion Map (MV-RAMDMM) formulation combined with appearance ... More
Bubble Wall Profiles With More Than One Scalar Field: A Numerical ApproachOct 27 1998Jan 31 1999We present a general numerical approach to solve the equations for bubble wall profiles in models with more than one scalar field and CP violating phases. We discuss the algorithm as well as several problems associated with it and show some profiles for ... More
The Need to Fairly Confront Spin-1 for the New Higgs-like ParticleNov 10 2012Spin-1 was ruled out early in LHC reports of a new particle with mass near 125 GeV. Actually the spin-1 possibility was dismissed on false premises, and remains open. Model-independent classification based on Lorentz invariance permits nearly two dozen ... More
Models for generalized spherical and related distributionsOct 22 2015A flexible model is developed for multivariate generalized spherical distributions, i.e. ones with level sets that are star shaped. To work in dimension above 2 requires tools from computational geometry and multivariate numerical integration. In order ... More
Surface Brightness Fluctuations as Stellar Population IndicatorsApr 01 2009Surface Brightness Fluctuations (SBF) can provide useful information about the unresolved stellar content of early-type galaxies and spiral bulges. The absolute SBF magnitude Mbar in a given passband depends on the properties of the stellar population ... More
Cluster-Cluster Lensing in Abell 2152Aug 15 2001We discuss lensing properties of the nearby cluster Abell 2152. Recent work shows that Abell 2152 is actually the projection of two different clusters, one of which is a Hercules supercluster member at z=0.043, while the other is more than 3 times as ... More
Huddled Masses Yearning to Stream Free: Globular Clusters in the Hearts of Galaxy ClustersSep 15 2000Sep 19 2000Extremely rich populations of globular clusters, numbering ten thousand or more, surround the central giant galaxies in rich clusters. I discuss some recent spectroscopic and photometric observations of these rich globular clusters populations. In very ... More
Hot Electrons and Cold Photons: Galaxy Clusters and the Sunyaev-Zel'dovich EffectNov 12 1997The hot gas in clusters of galaxies emits thermal bremsstrahlung emission that can be probed directly through measurements in the X-ray band with satellites like ROSAT and ASCA. Another probe of this gas comes from its effect on the cosmic microwave background ... More
Geometrical Optics via electromagnetic wave quantizationOct 28 2005The basic laws of geometrical optics can be deduced from energy-momentum conservation for electromagnetic waves, without other wave concepts. However, the concept of quanta is required; it arises naturally, hence such a hypothesis could have arisen earlier ... More
Classical and Quantum Integrable Systems in $\wt{\gr{gl}}(2)^{+*}$ and Separation of VariablesDec 03 1993Classical integrable Hamiltonian systems generated by elements of the Poisson commuting ring of spectral invariants on rational coadjoint orbits of the loop algebra $\wt{\gr{gl}}^{+*}(2,{\bf R})$ are integrated by separation of variables in the Hamilton-Jacobi ... More
Measuring co-authorship and networking-adjusted scientific impactJul 11 2008Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. ... More
Where and How to find $susy$: The auxiliary field interpretation of supersymmetryJun 20 2012The {\it gauge hierarchy problem} found in perturbation theory is one of the main attractions for supersymmetry. Yet the quantum mechanical coupling of a low energy system to a high energy one invariably leads to {\it perturbative instability}, which ... More
The Dependence of Globular Cluster Number on Density for Abell Cluster Central GalaxiesMar 15 1997A study of the globular cluster systems of 23 brightest, or central, galaxies in 19 Abell clusters has recently been completed. This Letter presents some of the newly discovered correlations of the globular cluster specific frequency $S_N$ in these galaxies ... More
Globular Clusters in Dense Clusters of GalaxiesJun 23 1999Deep imaging data from the Keck II telescope are employed to study the globular cluster (GC) populations in the cores of six rich Abell clusters. The sample includes A754, A1644, A2124, A2147, A2151, and A2152, and spans the redshift range z = 0.035-0.066. ... More
One Model Explains DAMA/LIBRA, CoGENT, CDMS, and XENONJun 28 2010Many experiments seek dark matter by detecting relatively low energy nuclear recoils. Yet since events from ordinary physics with energies in the 1-100 KeV range are commonplace, all claims of signals or their absence hinge on exhaustive calibrations ... More
Exploring Confinement with SpinOct 06 2008A confining gauge theory violates the completeness of asymptotic states held as foundation points of the $S$-matrix. Spin-dependent experiments can yield results that appear to violate quantum mechanics. The point is illustrated by violation of the Soffer ... More
Quantum Theory without Planck's ConstantMar 25 2012Planck's constant was introduced as a fundamental scale in the early history of quantum mechanics. We find a modern approach where Planck's constant is absent: it is unobservable except as a constant of human convention. Despite long reference to experiment, ... More
Question IsotropyNov 10 2010The "cosmological principle" was set up early without realizing its implications for the horizon problem, and almost entirely without support from observational data. Consistent signals of anisotropy have been found in data on electromagnetic propagation, ... More
Young Supernova Remnants in the Magellanic CloudsFeb 21 2001There are a half-dozen or so young supernova remnants in the Magellanic Clouds that display one or more of the following characteristics: high velocity (>1000 km/s) emission, enhanced metallicity, or a rapidly rotating pulsar. I summarize the current ... More
The Expansion of the X-ray Remnant of Tycho's Supernova (SN1572)Oct 05 2000Two ROSAT high resolution images separated by nearly five years have been used to determine the expansion of the X-ray remnant of Tycho's supernova (SN1572). The current expansion rate averaged over the entire remnant is $0.124\pm0.011$ % per yr, which, ... More
The Bohr Atom of GlueballsJan 14 2003Recently Buniy and Kephart made an astonishing empirical observation, which anyone can reproduce at home. Measure the {\it lengths} of closed knots tied from ordinary rope. The ``double do-nut'', and the beautiful trefoil knot are examples. Tie the knots ... More
A Proof, Based on the Euler Sum Acceleration, of the Recovery of an Exponential (Geometric) Rate of Convergence for the Fourier Series of a Function with Gibbs PhenomenonMar 27 2010When a function $f(x)$ is singular at a point $x_{s}$ on the real axis, its Fourier series, when truncated at the $N$-th term, gives a pointwise error of only $O(1/N)$ over the entire real axis. Such singularities spontaneously arise as "fronts" in meteorology ... More
The sum-capture problem for abelian groupsSep 22 2013Jan 06 2014Let $G$ be a finite abelian group, let $0 < \alpha < 1$, and let $A \subseteq G$ be a random set of size $|G|^\alpha$. We let $$ \mu(A) = \max_{B,C:|B|=|C|=|A|}|\{(a,b,c) \in A \times B \times C : a = b + c \}|. $$ The issue is to determine upper bounds ... More
The Spectropolarimetric Evolution of V838 MonocerotisJun 17 2006I review photo-polarimetric and spectropolarimetric observations of V838 Mon, which revealed that it had an asymmetrical inner circumstellar envelope following its 2nd photometric outburst. Electron scattering, modified by pre- or post-scattering H absorption, ... More
Testing the Supernova, Cepheid, and Early-type Galaxy Distance ScalesDec 14 2001I summarize recent work comparing relative distances measured to individual galaxies with independent methods. The comparisons include: ground-based surface brightness fluctuation (SBF) and fundamental plane distances to 170 galaxies, distances predicted ... More
Gravity-Darkened Seasons: Insolation Around Rapid RotatorsSep 22 2016I model the effect of rapid stellar rotation on a planet's insolation. Fast-rotating stars have induced pole-to-equator temperature gradients (known as gravity-darkening) of up to several thousand Kelvin that affect the star's luminosity and peak emission ... More
Truncated fractional moments of stable lawsSep 05 2017Expressions are given for the truncated fractional moments $E X_+^p$ of a general stable law. These involve families of special functions that arose out of the study of multivariate stable densities and probabilities. As a particular case, an expression ... More
Revisiting the Mass of the Coma Cluster from X-Ray ObservationsSep 26 1997I re-examine mass estimates of the Coma cluster from pre-ASCA X-ray spectral observations. A large range of model dark matter distributions are examined, under the assumptions of hydrostatic equilibrium and spherical symmetry, to determine the widest ... More
The Extraordinarily Rapid Expansion of the X-ray Remnant of Kepler's Supernova (SN1604)Jul 14 1999Four individual high resolution X-ray images from ROSAT and the Einstein Observatory have been used to measure the expansion rate of the remnant of Kepler's supernova (SN 1604). Highly significant measurements of the expansion have been made for time ... More
The Muon Experimental Anomalies Are Explained by a New Interaction Proportional to ChargeJun 20 2016The "proton size puzzle" and the "muon anomalous moment problem" are incomplete descriptions of significant discrepancies of Standard Model calculations with experiments. What is particularly new is that the experiments and theory confront a new regime ... More
Globular Clusters in Fornax: Does $M^0$ Depend on Environment?Apr 28 1996We present the $V$-band globular cluster luminosity functions (GCLFs) of the Fornax Cluster galaxies NGC 1344, NGC 1380, NGC 1399, and NGC 1404. Our observations reach to $V = 24.8$, roughly one magnitude beyond the GCLF turnover $m^0_V$, with $\sim90\%$ ... More
Bound-state signatures in quenched Bose-Einstein condensatesSep 01 2014Sep 03 2014We investigate the dynamics of a homogenous Bose-Einstein condensate (BEC) following a sudden quench of the scattering length. Our focus is the time evolution of short-range correlations via the dynamical contact. We compute the dynamics using a combination ... More
Ballistic quench-induced correlation waves in ultracold gasesMay 10 2016We investigate the wave packet dynamics of a pair of particles that undergoes a rapid change of scattering length. The short-range interactions are modeled in the zero-range limit, where the quench is accomplished by switching the boundary condition of ... More
Analysis and Transformation Tools for Constrained Horn Clause VerificationMay 15 2014Several techniques and tools have been developed for verification of properties expressed as Horn clauses with constraints over a background theory (CHC). Current CHC verification tools implement intricate algorithms and are often limited to certain subclasses ... More
Interpolant Tree Automata and their Application in Horn Clause VerificationJan 25 2016Jul 10 2016This paper investigates the combination of abstract interpretation over the domain of convex polyhedra with interpolant tree automata, in an abstraction-refinement scheme for Horn clause verification. These techniques have been previously applied separately, ... More
A Source-level Energy Optimization Framework for Mobile ApplicationsAug 18 2016Energy efficiency can have a significant influence on user experience of mobile devices such as smartphones and tablets. Although energy is consumed by hardware, software optimization plays an important role in saving energy, and thus software developers ... More
On the Metallicity-Color Relations and Bimodal Color Distributions in Extragalactic Globular Cluster SystemsSep 07 2007We perform a series of numerical experiments to study how the nonlinear metallicity--color relations predicted by different stellar population models affect the color distributions observed in extragalactic globular cluster systems. % We present simulations ... More
Extending Term Subsumption systems for Uncertainty ManagementMar 27 2013A major difficulty in developing and maintaining very large knowledge bases originates from the variety of forms in which knowledge is made available to the KB builder. The objective of this research is to bring together two complementary knowledge representation ... More
An Update on Cosmological Anisotropy in Electromagnetic PropagationAug 12 1997Aug 13 1997We review evidence for a new phenomenon in the propagation of radio waves across the Universe, an anisotropic rotation of the plane of polarization not accounted for by conventional physics.
Perdew-Zunger self-interaction correction: How wrong for uniform densities and large-Z atoms?Jan 31 2019Apr 08 2019Semi-local density functionals for the exchange-correlation energy of a many-electron system cannot be exact for all one-electron densities. In 1981, Perdew and Zunger (PZ) subtracted the fully-nonlocal self-interaction error orbital-by-orbital, making ... More
Indication of Anisotropy in Electromagnetic Propagation over Cosmological DistancesApr 20 1997We report a systematic rotation of the plane of polarization of electromagnetic radiation propagating over cosmological distances. The effect is extracted independently from Faraday rotation, and found to be correlated with the angular positions and distances ... More
Wall Velocity in the MSSMDec 06 2000We compute the wall velocity in the MSSM with W, tops and stops contributing to the friction. In a wide range of parameters including those which fulfil the requirements of baryogenesis we find a wall velocity of order v_w=O(0.01) much below the SM value. ... More
Interferometric Parallax: A Method for Measurement of Astronomical DistancesMar 10 2006Mar 27 2006We show that distances of objects at cosmological distances can be measured directly using interferometry. Our approach to interferometric parallax comes from analysis of 4-point amplitude and intensity correlations that can be generated from pairs of ... More
Supersymmetry and the Lorentz Fine Tuning ProblemFeb 11 2005May 19 2005If physics at the Planck scale requires new conceptions of space-time, then generic renormalizable field theories predict observable violations of Lorentz invariance in the low energy sector. The little recognized ``Lorentz Fine Tuning Problem'' comes ... More
Exclusive Hadronic Processes and Color TransparencyMar 13 2001We review the current status of high energy exclusive processes and color transparency.
A Measurement of the Hubble Constant from the X-Ray Properties and the Sunyaev-Zel'dovich Effect of CL0016+16Jan 19 1998A value of the Hubble constant has been determined from a comparison of the X-ray properties and Sunyaev-Zel'dovich effect of the distant rich cluster of galaxies CL0016+16. The cluster, as imaged by the ROSAT PSPC, is significantly elliptical and we ... More
Direct Ejecta Velocity Measurements of Tycho's Supernova RemnantMay 29 2016We present the first direct ejecta velocity measurements of Tycho's supernova remnant (SNR). Chandra's high angular resolution images reveal a patchy structure of radial velocities in the ejecta that can be separated into distinct redshifted, blueshifted, ... More
Perdew-Zunger self-interaction correction: How wrong for uniform densities and large-Z atoms?Jan 31 2019Semi-local density functionals for the exchange-correlation energy of a many-electron system cannot be exact for all one-electron densities. In 1981, Perdew and Zunger (PZ) subtracted the fully-nonlocal self-interaction error orbital-by-orbital, making ... More
The Proton Electromagnetic Form Factor $F_2$ and Quark Orbital Angular MomentumJun 21 2003We analyze the proton electromagnetic form factor ratio $R(Q^{2})=QF_2(Q^{2})/F_1(Q^{2})$ as a function of momentum transfer $Q^{2}$ within perturbative QCD. We find that the prediction for $R(Q^{2})$ at large momentum transfer $Q$ depends on the exclusive ... More
Anisotropy in the Distribution of Galactic Radio PolarizationsMar 14 1998Nov 22 2003Radiation traversing the observable universe provides powerful ways to probe anisotropy of electromagnetic propagation. A controversial recent study claimed a signal of dipole character. Here we test a new and independent data set of 361 points under ... More
Evidence for Observation of Color Transparency in pa Collisions Using Global Fit and Scaling Law AnalysisMay 26 1993We review a new systematic data analysis procedure for color transparency experiments and its application to the proton nucleus scattering experiment. The method extracts the hard scattering rate as well as the survival probability for the protons travelling ... More
Physical Properties of Four SZE-Selected Galaxy Clusters in the Southern Cosmology SurveyNov 21 2008Feb 06 2009We present the optical and X-ray properties of four clusters recently discovered by the South Pole Telescope (SPT) using the Sunyaev-Zel'dovich effect (SZE). The four clusters are located in one of the common survey areas of the southern sky that is also ... More
Chandra observations of the Abell S0295 clusterFeb 18 2019We present deep ($205 \rm ks$), \Chandra observations of the \ab295 binary merging cluster ($z=0.30$). In the X-ray image, the secondary component is clearly visible as a surface brightness peak, while the primary cluster has a flatter distribution. We ... More
Material properties of $α$-quartz that are relevant for its potential use in X-ray monochromators and analyzersDec 21 2016Jan 18 2017Monochromators and analyzers for X-rays of energy $>$ 5 keV are overwhelmingly made from silicon crystals, of which large specimens of high purity and low defect density are readily available. Germanium and diamond crystals are also occasionally used. ... More
Comment on Renormalization Group Study of the A+B->0 Diffusion-Limited ReactionDec 08 1996A recent argument of Oerding shows that our calculation of the quantity Delta, which determines the amplitude of the asymptotic decay of the particle density in d < 2 < 4, was in error. Instead it is simply given by Delta = n_0, the initial density, for ... More
Renormalization Group Study of the A+B->0 Diffusion-Limited ReactionDec 13 1994Apr 27 1995The $A + B\to 0$ diffusion-limited reaction, with equal initial densities $a(0) = b(0) = n_0$, is studied by means of a field-theoretic renormalization group formulation of the problem. For dimension $d > 2$ an effective theory is derived, from which ... More
Relic Abundance Predicts Universal Mass-Width Relations for Dark Matter InteractionsJun 09 2010We find new and universal relations for the properties of dark matter particles consistent with standard relic abundances. Analysis is based on first characterizing the $s$-channel resonant annihilation process in great detail, keeping track of all velocity-dependence, ... More
Limits on Threshold and "Sommerfeld" Enhancements in Dark Matter AnnihilationOct 07 2009Mar 04 2010We find model-independent upper limits on rates of dark matter annihilation in galactic halos. The Born approximation generally fails, while exotic threshold enhancements akin to "Sommerfeld factors" also turn out to be baseless The most efficient annihilation ... More
Convex polyhedral abstractions, specialisation and property-based predicate splitting in Horn clause verificationDec 03 2014We present an approach to constrained Horn clause (CHC) verification combining three techniques: abstract interpretation over a domain of convex polyhedra, specialisation of the constraints in CHCs using abstract interpretation of query-answer transformed ... More
Results on two-bit gate design for quantum computersSep 26 1994We present numerical results which show how two-bit logic gates can be used in the design of a quantum computer. We show that the Toffoli gate, which is a universal gate for all classical reversible computation, can be implemented using a particular sequence ... More
Cosmologically Screwy LightApr 20 1997We present evidence for a new phenomenon in the propagation of electromagnetic radiation across the Universe, a corkscrew rotation of the plane of polarization not accounted for by conventional physics.
Two-variable Wiman-Valiron theory and PDEs - ErratumSep 30 2010This note corrects Example 3.2 in Two-Variable Wiman-Valiron Theory and PDEs by the authors which appeared in Ann. Acad. Sci. Fenn Math. (35) (2010), 571-580.
Testing population synthesis models with globular cluster colorsJan 06 2000We have measured an extensive set of UBVRIJHK colors for M31 globular clusters [Barmby et al. 2000]. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31 globular clusters. ... More
Kinematics of the Hercules SuperclusterSep 26 1997The Hercules Supercluster consists of the Abell clusters 2147, 2151, and 2152. Previous studies of the kinematics have been confounded by the difficulty of correctly assigning galaxies to the individual clusters, which are not well-separated. Our study ... More
Universal Thermal Corrections to Single Interval Entanglement Entropy for Conformal Field TheoriesMar 03 2014Apr 14 2014We consider single interval R\'enyi and entanglement entropies for a two dimensional conformal field theory on a circle at nonzero temperature. Assuming that the finite size of the system introduces a unique ground state with a nonzero mass gap, we calculate ... More
Exploring the Micro-Structure of the Proton: from Form Factors to DVCSJul 10 2002For a long time people made the mistake of thinking the proton was understood. New experiments, ranging from form factors to deeply virtual Compton scattering, promise a new era of highly informative studies. Among the controversial topics of the future ... More
Evidence for Evolution or Bias in Host Extinctions of Type 1a Supernovae at High RedshiftJun 21 2005Oct 17 2005Type 1a supernova magnitudes conventionally include an additive parameter called the extinction coefficient. We find that the extinction coefficients of a popular ``gold'' set are well correlated with the deviation of magnitudes from Hubble diagrams. ... More
QCD Form Factors and Hadron Helicity Non-ConservationFeb 06 2003Recent data for the ratio $R(Q)= QF_{2}(Q^{2})/F_{1}(Q^{2})$ shocked the community by disobeying expectations held for 50 years. We examine the status of perturbative QCD predictions for helicity-flip form factors. Contrary to common belief, we find there ... More
Covariant Symmetry Classifications for Observables of Cosmological BirefringenceSep 23 1998Polarizations of electromagnetic waves from distant galaxies are known to be correlated with the source orientations. These quantities have been used to search for signals of cosmological birefringence. We review and classify transformation properties ... More
Evidence for Observation of Color Transparency in Proton Nucleus CollisionsMay 26 1993We introduce a data analysis procedure for color transparency experiments which is considerably less model dependent than the transparency ratio method. The new method is based on fitting the shape of the A dependence of the nuclear cross section at fixed ... More
Measuring Chirally Odd Wave Functions with Helicity Flip Form FactorsMay 12 1993We consider the role of chirally odd wave functions in hard exclusive reactions. Such wave functions have the quarks oriented in the opposite helicity configuration from those assumed in the short-distance limit and are generally associated with non-zero ... More
Systematic Analysis Method for Color Transparency ExperimentsMar 15 1993We introduce a data analysis procedure for color transparency experiments which is considerably less model dependent than the transparency ratio method. The new method is based on fitting the shape of the A dependence of the nuclear cross section at fixed ... More
The Dirac algebra and its physical interpretationOct 27 2000A version of the Dirac equation is derived from first principles using a combination of quaternions and multivariate 4-vectors. The nilpotent form of the operators used allows us to derive explicit expressions for the wavefunctions of free fermions, vector ... More
A Gauss Elimination Method for ResonancesJun 24 2009Jun 25 2009A Gaussian elimination form of inverse iteration within the complex coordinate approach is shown to produce a simple uniform method of finding both real bound state energies and complex resonant state energies for several problems which have been treated ... More
An Energy-Aware Programming Approach for Mobile Application Development Guided by a Fine-Grained Energy ModelMay 17 2016Energy efficiency has a significant influence on user experience of battery-driven devices such as smartphones and tablets. It is shown that software optimization plays an important role in reducing energy consumption of system. However, in mobile devices, ... More
Fine-Grained Energy Modeling for the Source Code of a Mobile ApplicationOct 14 2015May 18 2016Energy efficiency has a significant influence on user experience of battery-driven devices such as smartphones and tablets. The goal of an energy model for source code is to lay a foundation for the application of energy-saving techniques during software ... More
Raman amplification in the coherent wavebreaking regimeJul 15 2015Jun 16 2016In regimes far beyond the wavebreaking threshold of Raman amplification, we show that significant amplifcation can occur after the onset of wavebreaking, before phase mixing destroys the coherent coupling between pump, probe and plasma wave. Amplification ... More
Linear Dimensionality Reduction: Survey, Insights, and GeneralizationsJun 03 2014Mar 18 2016Linear dimensionality reduction methods are a cornerstone of analyzing high dimensional data, due to their simple geometric interpretations and typically attractive computational properties. These methods capture many data features of interest, such as ... More
On the Global Anisotropy of Cosmic Ray Data above $4 \times 10^{19}eV$Oct 01 2001Jul 15 2003The distribution of arrival directions of ultra-high energy cosmic rays may yield clues to their mysterious origin. We introduce a method of {\it invariant statistics} to analyze cosmic ray data which eliminates coordinate-dependent artifacts. When combined ... More
Response to Leahy's Comment on the Data's Indication of Cosmological BirefringenceJun 13 1997Jun 16 1997Recently, J. P. Leahy commented (astro-ph/9704285) on the indication of anisotropy in the propagation of radio waves over cosmological distances, published by Nodland and Ralston (B. Nodland and J. P. Ralston, Phys. Rev. Lett. 78, 3043 (1997); astro-ph/9704196). ... More
Femto-Photography of Protons to Nuclei with Deeply Virtual Compton ScatteringOct 04 2001Nov 20 2002Developments in deeply virtual Compton scattering allow the direct measurements of scattering amplitudes for exchange of a highly virtual photon with fine spatial resolution. Real-space images of the target can be obtained from this information. Spatial ... More
Do Stops Slow Down Electroweak Bubble Walls?Feb 04 2000Oct 14 2002We compute the wall velocity in the MSSM. We therefore generalize the SM equations of motion for bubble walls moving through a hot plasma at the electroweak phase transition and calculate the friction terms which describe the viscosity of the plasma. ... More
Electron-hole correlations govern Auger recombination in nanostructuresAug 30 2018The fast nonradiative decay of multiexcitonic states via Auger recombination is a fundamental process affecting a variety of applications based on semiconductor nanostructures. From a theoretical perspective, the description of Auger recombination in ... More
Three Successful Tests of Color Transparency and Nuclear FilteringOct 06 1993We review the theoretical formalism for hard exclusive processes in a nuclear medium. Theory suggests that these processes will show the very interesting phenomena of color transparency and nuclear filtering. The survival probability in nuclear media ... More
Freely Expanding Knots of X-ray Emitting Ejecta in Kepler's Supernova RemnantJul 26 2017We report measurements of proper motion, radial velocity, and elemental composition for 14 X-ray knots in Kepler's supernova remnant (SNR) using Chandra data. The highest speed knots show both large proper motions (0.11-0.14 "/yr) and high radial velocities ... More
Another X-ray-Discovered Poor Cluster of Galaxies Associated with CL 0016+16Nov 18 1997We report optical spectroscopic observations of RX J0018.8+1602, a ROSAT X-ray source proposed to be an intermediate redshift cluster of galaxies. Our observations confirm the identification of RX J0018.8+1602 and provide measurements of its mean radial ... More
Derived Equivalent Calabi-Yau 3-folds from Cubic 4-foldsAug 18 2014Sep 10 2015We describe pretty examples of derived equivalences and autoequivalences of Calabi-Yau threefolds arising from pencils of cubic fourfolds. The cubic fourfolds are chosen to be special, so they have an associated K3 surface. Thus a pencil gives rise to ... More
Scaling of Reaction Zones in the A+B->0 Diffusion-Limited ReactionAug 03 1994We study reaction zones in three different versions of the A+B->0 system. For a steady state formed by opposing currents of A and B particles we derive scaling behavior via renormalization group analysis. By use of a previously developed analogy, these ... More
Electronic transitions of jet-cooled SiC2, Si2Cn (n=1-3), Si3Cn (n=1,2), and SiC6H4 between 250 and 710 nmMar 17 2015Electronic transitions of the title molecules were measured between 250 and 710 nm using a mass-resolved 1+1' resonant two-photon ionization technique at a resolution of 0.1 nm. Calculations at the B3LYP/aug-cc-pVQZ level of theory support the analyses. ... More
Analysis Tools for Discovering Strong Parity Violation at Hadron CollidersJan 10 2011Jun 30 2011Several arguments suggest parity violation may be observable in high energy strong interactions. We introduce new analysis tools for describing the azimuthal dependence of multi-particle distributions, or "azimuthal flow." Analysis uses the representations ... More
Response to Eisenstein and Bunn's Null Hypothesis Comment on Cosmological BirefringenceMay 23 1997May 25 1997Eisenstein and Bunn have widely circulated a Comment (astro-ph/9704247) suggesting a non-standard null hypothesis in a test for cosmological birefringence. The Comment misrepresents the procedure used by Nodland and Ralston (B. Nodland and J. P. Ralston, ... More
Proceedings 3rd Workshop on Horn Clauses for Verification and SynthesisJul 14 2016This volume contains the proceedings of HCVS 2016, the Third Workshop on Horn Clauses for Verification and Synthesis which was held on April 3, 2016 in Eindhoven, The Netherlands as a satellite event of the European Joint Conferences on Theory and Practice ... More
Direct Ejecta Velocity Measurements of Tycho's Supernova RemnantMay 29 2016May 04 2017We present the first direct ejecta velocity measurements of Tycho's supernova remnant (SNR). Chandra's high angular resolution images reveal a patchy structure of radial velocities in the ejecta that can be separated into distinct redshifted, blueshifted, ... More
Classifying Polarization Observables of the Cosmic Microwave BackgroundOct 13 2006We revisit the classification of polarization observables of the cosmic microwave background. There exists a unified approach to the $3 \times 3$ density matrix by which intensity, linear and circular polarization are treated on an equal footing. The ... More
The Virgo Alignment Puzzle in Propagation of Radiation on Cosmological ScalesNov 18 2003Jun 21 2004We reconsider analysis of data on the cosmic microwave background on the largest angular scales. Temperature multipoles of any order factor naturally into a direct product of axial quantities and cosets. Striking coincidences exist among the axes associated ... More
Evidence for Gluon Energy Loss as the Mechanism for Heavy Quarkonium Suppression in $pA$ CollisionsJun 25 1994We study the energy and nuclear A dependence of the hadronic production of heavy quarkonia. We review theoretical ideas which have been put forward, seeking a consistent global picture reconciling the large effects in quarkonia with the small nuclear ... More
Interpretation of the Color Transparency ExperimentsDec 01 1992We argue that the experimentally measured color transparency ratio is directly related to the interacting hadron wave function at small transverse separation, $b^2<1/Q^2$. We show that the present experimental data is consistent with pure scaling behavior ... More
Electronic transport in normal-conductor/graphene/normal-conductor junctions and conditions for insulating behavior at a finite charge-carrier densityJun 11 2007Oct 11 2007We investigate the conductance of normal-conductor/graphene/normal-conductor (NGN) junctions for arbitrary on-site potentials in the normal and graphitic parts of the system. We find that a ballistic NGN junction can display insulating behavior even when ... More
Entanglement between static and flying qubits in an Aharonov-Bohm double electrometerApr 20 2006Oct 31 2007We consider the phase-coherent transport of electrons passing through an Aharonov-Bohm ring while interacting with a tunnel charge in a double quantum dot (representing a charge qubit) which couples symmetrically to both arms of the ring. For Aharonov-Bohm ... More
On The Low-Frequency Vibrational Modes of C$_{60}$Apr 10 1996The vibrational spectrum of C$_{60}$ is compared to the spectrum of a classical isotropic elastic spherical shell. We show correlations between the low frequency modes of C$_{60}$ and those of the spherical shell. We find the spherical model gives the ... More