Results for "Daniel Dale"

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Quark Propagation in the Instantons of Lattice QCDJun 14 2013Jul 16 2013We quantitatively examine the extent to which instanton degress of freedom, contained within standard Monte-carlo generated gauge-field configurations, can maintain the characteristic features of the mass and renormalisation functions of the non-perturbative ... More
Shrinking of Cluster Ellipticals: a Tidal Stripping explanation and Implications for the Intra-Cluster LightFeb 01 2006We look for evidence of tidal stripping in elliptical galaxies through the analysis of homogeneous CCD data corresponding to a sample of 228 elliptical galaxies belonging to 24 clusters of galaxies at $0.015<z<0.080$. We investigate departures from the ... More
Ab initio calculations of the atomic and electronic structures of crystalline PEO3:LiCF3SO3 electrolytesOct 20 2015The PEO3:LiCF3SO3 polymer electrolyte has attracted significant research due to its enhanced stability at the lithium/polymer interface of high conductivity polymer batteries. Experimental studies have shown that, depending on the preparation conditions, ... More
A topological view of ordered groupsMar 19 2014We show how to use topological ideas, such as compactness, to establish orderability properties of infinite groups. A new application is to provide a left-ordering for the group of PL homeomorphisms of a connected surface with boundary which are fixed ... More
Low Dimensional Topology and Ordering GroupsMar 19 2014This expository paper explores the interaction of group ordering with topological questions, especially in dimensions 2 and 3. Among the topics considered are surfaces, braid groups, 3-manifolds and their structures such as foliations and mappings between ... More
The Infrared Spectral Energy Distribution of Normal Star-Forming Galaxies: Calibration at Far-Infrared and Submillimeter WavelengthsMay 06 2002May 06 2002New far-infrared and submillimeter data are used to solidify and to extend to long wavelengths the empirical calibration of the infrared spectral energy distribution (SED) of normal star-forming galaxies. As was found by Dale et al. (2001), a single parameter ... More
Effective local connectivity propertiesJun 16 2011Sep 16 2011We investigate, and prove equivalent, effective versions of local connectivity and uniformly local arcwise connectivity for connected and computably compact subspaces of Euclidean space. We also prove that Euclidean continua that are computably compact ... More
The Convergence Depth of the Local Peculiar Velocity FieldAug 31 1999We have obtained Tully-Fisher (TF) measurements for some 3000 late-type galaxies in the field and in 76 clusters distributed throughout the sky between 10 and 200\h Mpc. The cluster data are applied to the construction of an I band TF template, resulting ... More
Nebular Attenuation in Hα-selected Star-forming Galaxies at z=0.8 from the NewHα SurveyJul 23 2012We present measurements of the dust attenuation of H\alpha-selected emission-line galaxies at z=0.8 from the NewH\alpha\ narrowband survey. The analysis is based on deep follow-up spectroscopy with Magellan/IMACS, which captures the strong rest-frame ... More
Signatures of Galaxy-Cluster Interactions: Tully-Fisher Observations at z~0.1Apr 21 2003We have obtained new optical imaging and spectroscopic observations of 78 galaxies in the fields of the rich clusters Abell 1413 (z = 0.14), Abell 2218 (z = 0.18) and Abell 2670 (z = 0.08). We have detected line emission from 25 cluster galaxies plus ... More
Signatures of Interstellar-Intracluster Medium Interactions: Spiral Galaxy Rotation Curves in Abell 2029Apr 11 2000We investigate the rich cluster Abell 2029 (z~0.08) using optical imaging and long-slit spectral observations of 52 disk galaxies distributed throughout the cluster field. No strong emission-line galaxies are present within ~400 kpc of the cluster center, ... More
Mid-Infrared Spectral Diagnostics of Nearby GalaxiesApr 01 2006The Spitzer Space Telescope is pushing into new frontiers in high redshift astronomy. Closer to home, Spitzer is making an equally large impact on our understanding of galaxy formation and evolution. In this contribution we present mid-infrared diagnostics ... More
Uniform exponential mixing and resonance free regions for convex cocompact congruence subgroups of $\operatorname{SL}_2(\mathbb{Z})$Oct 16 2014Sep 21 2015Let $\Gamma<\mathrm{SL}_2(\mathbb{Z})$ be a non-elementary finitely generated subgroup and let $\Gamma(q)$ be its congruence subgroup of level $q$ for each $q\in \mathbb{N}$. We obtain an asymptotic formula for the matrix coefficients of $L^2(\Gamma (q) ... More
Bandit-Based Model Selection for Deformable Object ManipulationMar 29 2017We present a novel approach to deformable object manipulation that does not rely on highly-accurate modeling. The key contribution of this paper is to formulate the task as a Multi-Armed Bandit problem, with each arm representing a model of the deformable ... More
Free group automorphisms, invariant orderings and topological applicationsMay 25 2001We are concerned with orderable groups and particularly those with orderings invariant not only under multiplication, but also under a given automorphism or family of automorphisms. Several applications to topology are given: we prove that the fundamental ... More
Using young massive star clusters to understand star formation and feedback in high-redshift-like environmentsJan 11 2016The formation environment of stars in massive stellar clusters is similar to the environment of stars forming in galaxies at a redshift of 1 - 3, at the peak star formation rate density of the Universe. As massive clusters are still forming at the present ... More
Average Metallicity and Star Formation Rate of Lya Emitters Probed by a Triple Narrow-Band SurveyMay 13 2011Dec 02 2011We present the average metallicity and star-formation rate of Lya emitters (LAEs) measured from our large-area survey with three narrow-band (NB) filters covering the Lya, [OII]3727, and Ha+[NII] lines of LAEs at z=2.2. We select 919 z=2.2 LAEs from Subaru/Suprime-Cam ... More
Electronic bandstructure and van der Waals coupling of ReSe2 revealed by high-resolution angle-resolved photoemission spectroscopyApr 01 2017ReSe2 and ReS2 are unusual compounds amongst the layered transition metal dichalcogenides as a result of their low symmetry, with a characteristic in-plane anisotropy due to in-plane rhenium chains. They preserve inversion symmetry independent of the ... More
Cause and Extent of the Extreme Radio Flux Density Reached by the Solar Flare of 2006 December 06Jan 26 2019The solar burst of 2006 December 06 reached a radio flux density of more than 1 million solar flux units (1 sfu = $10^{-22}$ W/m$^2$/Hz), as much as 10 times the previous record, and caused widespread loss of satellite tracking by GPS receivers. The event ... More
Groups of PL homeomorphisms of cubesJan 03 2014We study algebraic properties of groups of PL or smooth homeomorphisms of unit cubes in any dimension, fixed pointwise on the boundary, and more generally PL or smooth groups acting on manifolds and fixing pointwise a submanifold of codimension 1 (resp. ... More
Structural Analysis of Superconducting Accelerator CavitiesAug 21 2000The static and dynamic structural behavior of superconducting cavities for various projects was determined by finite element structural analysis. The b = 0.61 cavity shape for the Neutron Science Project was studied in detail and found to meet all design ... More
Spectral Analysis of Iterated Rank-One PerturbationsFeb 07 2019The authors study the spectral theory of self-adjoint operators that are subject to certain types of perturbations. An iterative introduction of infinitely many randomly coupled rank-one perturbations is one of our settings. Spectral theoretic tools are ... More
Equilibria of Pendant Droplets: Spatial Variation and Anisotropy of Surface TensionApr 07 2019An example of capillary phenomena commonly seen and often studied is a droplet of water hanging in air from a horizontal surface. A thin capillary surface interface between the liquid and gas develops tangential surface tension, which provides a balance ... More
Mixed multiplicities of Divisorial FiltrationsMay 04 2019Suppose that $R$ is an excellent local domain with maximal ideal $m_R$. The theory of multiplicities and mixed multiplicities of $m_R$-primary ideals extends to (possibly non Noetherian) filtrations of $R$ by $m_R$-primary ideals, and many of the classical ... More
Ramification of valuations and local ringsAug 09 2015In this paper we consider birational properties of ramification in excellent local rings. We extend earlier results of the author with Olivier Piltant to show that strong local monomialization is true along a valuation dominating a defectless extension ... More
Finite Generation of Extensions of Associated Graded Rings Along a ValuationApr 19 2017May 03 2018In this paper we consider the question of when the associated graded ring along a valuation, ${\rm gr}_{\nu^*}(S)$, is a finite ${\rm gr}_{\nu^*}(R)$-module, where $S$ is a normal local ring which lies over a normal local ring $R$ and $\nu^*$ is a valuation ... More
Toroidalization of birational morphisms of 3-foldsJul 14 2004Apr 17 2005We prove that a birational morphism of projective 3-folds, over a field of characteristic zero, can be made toroidal by performing a sequence of blow ups of points and nonsingular curves above the domain and target.
Measuring Galaxy Star Formation Rates From Integrated Photometry: Insights from Color-Magnitude Diagrams of Resolved StarsMay 30 2013We use empirical star formation histories (SFHs), measured from HST-based resolved star color-magnitude diagrams, as input into population synthesis codes to model the broadband spectral energy distributions (SEDs) of ~50 nearby dwarf galaxies (6.5 < ... More
Rank/Norm Regularization with Closed-Form Solutions: Application to Subspace ClusteringFeb 14 2012Oct 09 2012When data is sampled from an unknown subspace, principal component analysis (PCA) provides an effective way to estimate the subspace and hence reduce the dimension of the data. At the heart of PCA is the Eckart-Young-Mirsky theorem, which characterizes ... More
Complexity of weakly null sequencesFeb 28 1992We introduce an ordinal index which measures the complexity of a weakly null sequence, and show that a construction due to J. Schreier can be iterated to produce for each alpha < omega_1, a weakly null sequence (x^{alpha}_n)_n in C(omega^{omega^{alpha}})) ... More
No Hubble Bubble in the Local UniverseJun 23 1999Zehavi et al. (1998) have suggested that the Hubble flow within 70/h Mpc may be accelerated by the existence of a void centered on the Local Group. Its underdensity would be ~20 %, which would result in a local Hubble distortion of about 6.5 %. We have ... More
A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space ObservatoryMay 19 2008Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory. The galaxy sample includes normal star-forming systems, starbursts, and active galactic ... More
Cloud structure of three Galactic infrared dark star-forming regions from combining ground and space based bolometric observationsApr 21 2017We have modified the iterative procedure introduced by Lin et al. (2016), to systematically combine the submm images taken from ground based (e.g., CSO, JCMT, APEX) and space (e.g., Herschel, Planck) telescopes. We applied the updated procedure to observations ... More
Mid-Infrared Observations of Normal Star-Forming Galaxies: The Infrared Space Observatory Key Project SampleMay 04 2000We present mid-infrared maps and preliminary analysis for 61 galaxies observed with the ISOCAM instrument aboard the Infrared Space Observatory. Many of the general features of galaxies observed at optical wavelengths---spiral arms, disks, rings, and ... More
The Extended Disk Galaxy Exploration Science Survey: Description and Surface Brightness Profile PropertiesMar 29 2019The survey description and near-infrared properties for 92 galaxies are presented for the Extended Disc Galaxy Exploration Science (EDGES) Survey, along with an investigation into the properties of the stellar halos of these galaxies. EDGES is a Spitzer ... More
A Joint Model of the X-ray And Infrared Extragalactic Backgrounds: I. Model Construction And First ResultsDec 15 2012We present an extragalactic population model of the cosmic background light to interpret the rich high-quality survey data in the X-ray and IR bands. The model incorporates star-formation and supermassive black hole (SMBH) accretion in a co-evolution ... More
Star Formation Histories of the LEGUS Spiral Galaxies. I. The flocculent spiral NGC 7793Apr 30 2019We present a detailed study of the flocculent spiral galaxy NGC 7793, part of the Sculptor group. By analyzing the resolved stellar populations of the galaxy, located at a distance of ~3.7 Mpc, we infer for the first time its radial star formation history ... More
Computing conformal maps onto circular domainsJul 24 2013We show that, given a non-degenerate, finitely connected domain $D$, its boundary, and the number of its boundary components, it is possible to compute a conformal mapping of $D$ onto a circular domain \emph{without} prior knowledge of the circular domain. ... More
The Physics of Pair Density WavesApr 22 2019Apr 24 2019We review the physics of pair density wave (PDW) superconductors. We begin with a macroscopic description that emphasizes order induced by PDW states, such as charge density wave, and discuss related vestigial states that emerge as a consequence of partial ... More
Linear independence of Gamma values in positive characteristicJun 08 2001We investigate the arithmetic nature of special values of Thakur's function field Gamma function at rational points. Our main result is that all linear independence relations over the field of algebraic functions are consequences of the known relations ... More
Generalized Laguerre Reduction of the Volterra Kernel for Practical Identification of Nonlinear Dynamic SystemsOct 03 2014The Volterra series can be used to model a large subset of nonlinear, dynamic systems. A major drawback is the number of coefficients required model such systems. In order to reduce the number of required coefficients, Laguerre polynomials are used to ... More
Scaling Relations of Local Spiral Galaxies.I. Observational FoundationsOct 15 2003(Abridged) This paper presents an exploration of two fundamental scaling relations of spiral galaxies, the luminosity-rotation speed (or Tully-Fisher; TF) relation, and the size-luminosity (SL) relation, and the dependences of their scatter, at red and ... More
No preferential spatial distribution for massive stars expected from their formationMay 12 2017We analyse N-body and Smoothed Particle Hydrodynamic (SPH) simulations of young star-forming regions to search for differences in the spatial distributions of massive stars compared to lower-mass stars. The competitive accretion theory of massive star ... More
Valuation Semigroups of Two Dimensional Local RingsMay 07 2011Apr 29 2014We consider the question of when a semigroup is the semigroup of a valuation dominating a two dimensional noetherian local domain, giving some surprising examples. We give a necessary and sufficient condition for the pair of a semigroup S and a field ... More
Growth of rank 1 valuation semigroupsSep 20 2008We consider the question of which semigroups can occur as the semigroup $S_R(\nu)$ of positive values of a rank 1 valuation dominating a Noetherian local ring $R$. We give a number of bounds of polynomial type on the growth of $\phi(n)=S_R(\nu)\cap (0,n)$ ... More
Modeling Intercalated Group-4-Metal Nitride Halide Superconductivity with Interlayer Coulomb CouplingAug 11 2015Behavior consistent with Coulomb-mediated high-T$_C$ superconductivity is shown to be present in the intercalated group-4-metal nitride halides A$_x$(S)$_y$MNX, where the MNX host (M = Ti, Zr, Hf; X = Cl, Br) is partially intercalated with cations A$_x$ ... More
Nominal AbstractionAug 10 2009Sep 23 2010Recursive relational specifications are commonly used to describe the computational structure of formal systems. Recent research in proof theory has identified two features that facilitate direct, logic-based reasoning about such descriptions: the interpretation ... More
On the spatial distributions of stars and gas in numerical simulations of molecular cloudsJun 01 2015We compare the spatial distribution of stars which form in hydrodynamical simulations to the spatial distribution of the gas, using the $\mathcal{Q}$-parameter. The $\mathcal{Q}$-parameter enables a self-consistent comparison between the stars and gas ... More
Banach function algebras with dense invertible groupNov 03 2004In an earlier paper, Dawson and the second author asked whether or not a Banach function algebra with dense invertible group can have a proper Shilov boundary. We give an example of a uniform algebra showing that this can happen, and investigate the properties ... More
Generalized Conditional Gradient for Sparse EstimationOct 17 2014Structured sparsity is an important modeling tool that expands the applicability of convex formulations for data analysis, however it also creates significant challenges for efficient algorithm design. In this paper we investigate the generalized conditional ... More
Positivity of Mixed Multiplicities of FiltrationsMay 04 2019The theory of mixed multiplicities of filtrations by $m$-primary ideals in a ring is introduced in a recent paper by Cutkosky, Sarkar and Srinivasan. In this paper, we consider the positivity of mixed multiplicities of filtrations. We show that the mixed ... More
Comment on "Superconductivity in electron-doped layered TiNCl with variable interlayer coupling"Nov 18 2014In their article, Zhang et al. [Phys. Rev. B 86, 024516 (2012)] present a remarkable result for A$_x$(S)$_y$TiNCl compounds ($\alpha$-phase TiNCl partially intercalated with alkali A and optionally co-intercalated molecular species S), finding the superconducting ... More
Mapping the wavefunction of transition metal acceptor states in the GaAs surfaceJul 27 2009We utilize a single atom substitution technique with spectroscopic imaging in a scanning tunneling microscope (STM) to visualize the anisotropic spatial structure of magnetic and non-magnetic transition metal acceptor states in the GaAs (110) surface. ... More
[O I] 63 micron Emission from High and Low Luminosity AGN GalaxiesDec 09 2003The Infrared Space Observatory was used to search for a tracer of the warm and dense neutral interstellar medium, the [O I] 63.18 micron line, in four ultraluminous IRAS sources lying at redshifts between 0.6 and 1.4. While these sources are quasars, ... More
Seeking the Local Convergence Depth. V. Tully-Fisher Peculiar Velocities for 52 Abell ClustersJul 05 1999Jul 08 1999We have obtained I band Tully-Fisher (TF) measurements for 522 late-type galaxies in the fields of 52 rich Abell clusters distributed throughout the sky between 50 and 200\h Mpc. Here we estimate corrections to the data for various forms of observational ... More
The Nature of Infrared Emission in the Local Group Dwarf Galaxy NGC 6822 As Revealed by SpitzerAug 11 2006We present Spitzer imaging of the metal-deficient (Z ~30% Z_sun) Local Group dwarf galaxy NGC 6822. On spatial scales of ~130 pc, we study the nature of IR, H alpha, HI, and radio continuum emission. Nebular emission strength correlates with IR surface ... More
The Spatially Resolved [CII] Cooling Line Deficit in GalaxiesNov 04 2016We present [CII] 158um measurements from over 15,000 resolved regions within 54 nearby galaxies of the KINGFISH program to investigate the so-called [CII] "line cooling deficit" long known to occur in galaxies with different luminosities. The [CII]/TIR ... More
The Stellar Halo and Tidal Streams of Messier 63Oct 19 2015We present new near-infrared (NIR) observations of M63 from the Extended Disk Galaxy Exploration Science (EDGES) Survey. The extremely deep 3.6 $\mu$m mosaic reaches 29 AB mag arcsec$^{-2}$ at the outer reaches of the azimuthally-averaged surface brightness ... More
Warm and Cold Molecular Gas in GalaxiesJan 20 2005New and archival interferometric 12CO(1->0) datasets from six nearby galaxies are combined with H_2 2.122um and H-alpha maps to explore in detail the interstellar medium in different star-forming galaxies. We investigate the relation between warm (H_2 ... More
Seeking the Local Convergence Depth. The Abell Cluster Dipole Flow to 200 Mpc/hOct 28 1998We have obtained new Tully-Fisher (TF) peculiar velocity measurements for 52 Abell galaxy clusters distributed throughout the sky between ~ 50 and 200 Mpc/h.The measurements are based on I band photometry and optical rotation curves for a sample of 522 ... More
Signatures of Galaxy-Cluster Interactions: Spiral Galaxy Rotation Curve Asymmetry, Shape, and ExtentDec 18 2000The environmental dependencies of the characteristics of spiral galaxy rotation curves are studied in this work. We use our large, homogeneously collected sample of 510 cluster spiral galaxy rotation curves to test the claim that the shape of a galaxy's ... More
The Infrared Spectral Energy Distribution of Normal Star-Forming GalaxiesNov 01 2000We present a new phenomenological model for the spectral energy distribution of normal star-forming galaxies between 3 and 1100 microns. A sequence of realistic galaxy spectra are constructed from a family of dust emission curves assuming a power law ... More
Evidence for the Heating of Atomic Interstellar Gas by PAHsOct 19 2000Nov 20 2000We report a strong correlation between the [CII] 158 micron cooling line and the mid-infrared flux in the 5-10 micron range in a wide variety of star-forming galaxies. The mid-infrared flux is dominated by Aromatic Feature Emission (AFE), which is thought ... More
Pressure enhanced interplay among lattice, spin and charge in La2FeMnO6 mixed perovskiteMay 04 2019Spin crossover plays a central role in the structural instability, net magnetic moment modification, metallization, and even in superconductivity in corresponding materials. Most reports on the pressure-induced spin crossover with a large volume collapse ... More
The Connection Between Galaxy Environment and the Luminosity Function Slopes of Star-Forming RegionsJul 13 2016Jul 29 2016We present the first study of GALEX far ultra-violet (FUV) luminosity functions of individual star-forming regions within a sample of 258 nearby galaxies spanning a large range in total stellar mass and star formation properties. We identify ~65,000 star-forming ... More
The Nature of the Second Parameter in the IRX-beta Relation for Local GalaxiesJul 05 2013We present an analysis of 98 galaxies of low-dust content, selected from the Spitzer Local Volume Legacy survey, aimed at examining the relation between the ultraviolet (UV) color, beta, and dust attenuation in normal star-forming galaxies. The IRX-beta ... More
Science with an ngVLA: The ngVLA Science Case and Associated Science RequirementsOct 15 2018The science case and associated science requirements for a next-generation Very Large Array (ngVLA) are described, highlighting the five key science goals developed out of a community-driven vision of the highest scientific priorities in the next decade. ... More
A Two-Parameter Model for the Infrared/Submillimeter/Radio Spectral Energy Distributions of Galaxies and AGNFeb 06 2014A two-parameter semi-empirical model is presented for the spectral energy distributions of galaxies with contributions to their infrared-submillimeter-radio emission from both star formation and accretion disk-powered activity. This model builds upon ... More
Multiwavelength Observations of the Low Metallicity Blue Compact Dwarf Galaxy SBS 0335-052Jul 05 2001New infrared and millimeter observations from Keck, Palomar, ISO, and OVRO and archival data from the NRAO VLA and IRAS are presented for the low metallicity blue compact dwarf galaxy SBS 0335-052. Mid-infrared imaging shows this young star-forming system ... More
Towards an Understanding of the Mid-Infrared Surface Brightness of Normal GalaxiesAug 09 1999We report a mid-infrared color and surface brightness analysis of IC 10, NGC 1313, and NGC 6946, three of the nearby galaxies studied under the Infrared Space Observatory Key Project on Normal Galaxies. Images with < 9 arcsecond (170 pc) resolution of ... More
Early-time VLA observations and broad-band afterglow analysis of the Fermi-LAT detected GRB 130907ANov 26 2014Jul 21 2015We present multi-wavelength observations of the hyper-energetic gamma-ray burst (GRB) 130907A, a Swift-discovered burst with early radio observations starting at $\approx 4$ hr after the $\gamma$-ray trigger. GRB 130907A was also detected by the Fermi/LAT ... More
Seeking the Local Convergence Depth. IV. Tully-Fisher Observations of 35 Abell ClustersJul 05 1999We present Tully-Fisher observations for 35 rich Abell clusters of galaxies. Results from I band photometry and optical rotation curve work comprise the bulk of this paper. This is the third such data installment of an all-sky survey of 52 clusters in ... More
Seeking the Local Convergence Depth. II. TF Observations of the Clusters A114, A119, A194, A2295, A2457, A2806, A3193, A3381, AND A3744Nov 06 1997We present Tully-Fisher (TF) observations for nine rich Abell clusters of galaxies. This is the second such data installment of an all-sky survey of 50 clusters in the redshift range 0.02 < z < 0.06. The data extends the TF study of nearby clusters of ... More
Seeking the Local Convergence Depth. I. TF Observations of the Clusters A168, A397, A569, A1139, A1228, and A1983May 11 1997We present first results of an all-sky observing program designed to improve the quality of the I band Tully-Fisher (TF) template and to obtain the reflex motion of the Local Group with respect to clusters to z = 0.06. We are obtaining between 5 and 15 ... More
Ultraviolet Through Far-Infrared Spatially Resolved Analysis of the Recent Star Formation in M81 (NGC3031)May 23 2006The recent star formation (SF) in the early-type spiral galaxy M81 is characterized using imaging observations from the far-ultraviolet (UV) to the far-infrared (IR). We compare these data with models of the stellar, gas, and dust emission for sub-galactic ... More
L-Edge Spectroscopy of Dilute, Radiation-Sensitive Systems Using a Transition-Edge-Sensor ArrayJun 29 2017Aug 18 2017We present X-ray absorption spectroscopy and resonant inelastic X-ray scattering (RIXS) measurements on the iron L-edge of 0.5 mM aqueous ferricyanide. These measurements demonstrate the ability of high-throughput transition-edge-sensor (TES) spectrometers ... More
Large-scale effects of ionizing feedbackSep 27 2012I discuss recent work on gas expulsion and triggered star formation in, and unbinding of, embedded clusters, by ionizing radiation from O-type stars. Photoionization is not as effective a driver of any of these process as was perhaps once thought. Although ... More
Tutorial on the braid groupsOct 19 2010This is an introduction to the braid groups, as presented in the summer school and workshop on braid groups at the National University of Singapore in June 2007.
Ordered groups as a tensor categoryApr 09 2017It is a classical theorem that the free product of ordered groups is orderable. In this note we show that, using a method of G. Bergman, an ordering of the free product can be constructed in a functorial manner, in the category of ordered groups and order-preserving ... More
Collection analysis for Horn clause programsAug 16 2007We consider approximating data structures with collections of the items that they contain. For examples, lists, binary trees, tuples, etc, can be approximated by sets or multisets of the items within them. Such approximations can be used to provide partial ... More
CTCF-mediated transcriptional regulation through cell type-specific chromosome organization in the β-globin locusJun 26 2012The principles underlying the architectural landscape of chromatin beyond the nucleosome level in living cells remains largely unknown despite its potential to play a role in mammalian gene regulation. We investigated the 3-dimensional folding of a 1 ... More
EOVSA Implementation of a Spectral Kurtosis Correlator for Transient Detection and ClassificationFeb 17 2017We describe in general terms the practical use in astronomy of a higher-order statistical quantity called Spectral Kurtosis (SK), and describe the first implementation of SK-enabled firmware in the F-engine (Fourier transform-engine) of a digital FX correlator ... More
Old pre-main-sequence Stars: Disc reformation by Bondi-Hoyle accretionMay 23 2014Young stars show evidence of accretion discs which evolve quickly and disperse with an e-folding time of $\sim$ 3Myr. This is in striking contrast with recent observations that suggest evidence for numerous $>30$ Myr old stars with an accretion disc in ... More
The Effect of `Probability Skew' in Bell-test ExperimentsAug 27 2017We consider typical experiments that use Bell-inequalities to test local-realist theories of quantum mechanics and gain insight into how certain results can be obtained. We see that results against local-realism arise from some `quantum skew' of the correlation ... More
Connecting Particle Physics and Cosmology: Measuring the Dark Matter Relic Density in Compressed Supersymmetry at the LHCJan 11 2018The identity of Dark Matter (DM) is one of the most captivating topics in particle physics today. The R-parity conserving Minimal Supersymmetric Standard Model (MSSM), which naturally provides a DM candidate in the form of the lightest neutralino ($\tilde{\chi}_{1}^{0}$), ... More
Parsing as Tree TraversalJul 29 1994This paper presents a unified approach to parsing, in which top-down, bottom-up and left-corner parsers are related to preorder, postorder and inorder tree traversals. It is shown that the simplest bottom-up and left-corner parsers are left recursive ... More
Exponential Mixing of Frame Flow for Convex Cocompact Hyperbolic ManifoldsDec 03 2016The aim of this paper is to establish exponential mixing of frame flow for the measure of maximal entropy on a convex cocompact hyperbolic manifold. Consequences include results on the decay of matrix coefficients and on effective equidistribution of ... More
The dual of the Bourgain-Delbaen spaceMay 18 1998Sep 26 2003It is shown that a script L_infty-space with separable dual constructed by Bourgain and Delbaen has small Szlenk index and thus does not have a quotient isomorphic to C(omega^omega). It follows that this is a script L_infty-space which is the same size ... More
Exploring the Roper wave function in Lattice QCDDec 09 2013Using a correlation matrix analysis consisting of a variety of smearings, the CSSM Lattice collaboration has successfully isolated states associated with the Roper resonance and other "exotic" excited states such as the $\Lambda(1405)$ on the lattice ... More
Fibers of rational maps and Jacobian matricesOct 01 2017A rational map $\phi: \mathbb{P}_k^m \dashrightarrow \mathbb{P}_k^n$ is defined by homogeneous polynomials of a common degree $d$. We establish a linear bound in terms of $d$ for the number of $(m-1)$-dimensional fibers of $\phi$, by using ideals of minors ... More
Digital holographic microscopy for the evaluation of human sperm structureJul 12 2013The morphology of the sperm head has often been correlated with the outcome of in vitro fertilization (IVF), and has been shown to be the sole parameter in semen of value in predicting the success of intracytoplasmic sperm injection (ICSI) and intracytoplasmic ... More
Random Sentences from a Generalized Phrase-Structure Grammar InterpreterFeb 14 2007In numerous domains in cognitive science it is often useful to have a source for randomly generated corpora. These corpora may serve as a foundation for artificial stimuli in a learning experiment (e.g., Ellefson & Christiansen, 2000), or as input into ... More
Generating One-Anaphoric Expressions: Where Does the Decision Lie?May 09 1995Most natural language generation systems embody mechanisms for choosing whether to subsequently refer to an already-introduced entity by means of a pronoun or a definite noun phrase. Relatively few systems, however, consider referring to entites by means ... More
Mixing of frame flow for rank one locally symmetric spaces and measure classificationMar 10 2014Let $G$ be a connected simple linear Lie group of rank one, and let $\Gamma <G$ be a discrete Zariski dense subgroup admitting a finite Bowen-Margulis-Sullivan measure $m^{\operatorname{BMS}}$. We show that the right translation action of the one dimensional ... More
Term Encoding of Typed Feature StructuresDec 22 1995This paper presents an approach to Prolog-style term encoding of typed feature structures. The type feature structures to be encoded are constrained by appropriateness conditions as in Carpenter's ALE system. But unlike ALE, we impose a further independently ... More
Wave Function of the Roper from Lattice QCDApr 01 2013Jul 26 2013We apply the eigenvectors from a variational analysis in lattice QCD to successfully extract the wave function of the Roper state, and a higher mass P_11 state of the nucleon. We use the 2+1 flavour 32^3x64 PACS-CS configurations at a near physical pion ... More
A controlled study of cold dust content in galaxies from $z=0-2$May 30 2017Jun 01 2017At $z=1-3$, the formation of new stars is dominated by dusty galaxies whose far-IR emission indicates they contain colder dust than local galaxies of a similar luminosity. We explore the reasons for the evolving IR emission of similar galaxies over cosmic ... More
Untangling the Nature of Spatial Variations of Cold Dust Properties in Star Forming GalaxiesMay 19 2014We investigate the far-infrared (IR) dust emission for 20 local star forming galaxies from the Key Insights on Nearby Galaxies: A Far-IR Survey with Herschel (KINGFISH) sample. We model the far-IR/submillimeter spectral energy distribution (SED) using ... More
ExoPTF Science Uniquely Enabled by Far-IR Interferometry: Probing the Formation of Planetary Systems, and Finding and Characterizing ExoplanetsJul 05 2007By providing sensitive sub-arcsecond images and integral field spectroscopy in the 25 - 400 micron wavelength range, a far-IR interferometer will revolutionize our understanding of planetary system formation, reveal otherwise-undetectable planets through ... More
Luminous and obscured quasars and their host galaxiesDec 19 2017The most heavily-obscured, luminous quasars might represent a specific phase of the evolution of actively accreting supermassive black holes and their host galaxies, possibly related to mergers. We investigated a sample of the most luminous quasars at ... More