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Gravitational backreaction simulations of simple cosmic string loopsMar 14 2019We present the results of computational gravitational backreaction on simple models of cosmic string loops. These results give us insight into the general behavior of cusps and kinks on loops, in addition to other features of evolution. Kinks are rounded ... More

Predicting the Influence of Plate Geometry on the Eddy Current PendulumJun 21 2015We quantitatively analyze a familiar classroom demonstration, Van Waltenhofen's eddy current pendulum, to predict the damping effect for a variety of plate geometries from first principles. Results from conformal mapping, finite element simulations and ... More

The future of census coverage surveysMay 19 2008A quarter-century of statistical research has shown that census coverage surveys, valuable as they are in offering a report card on each decennial census, do not provide usable estimates of geographical differences in coverage. The determining reason ... More

Quantum kinematics on q-deformed quantum spaces I, Mathematical FrameworkDec 20 2006The aim of these two papers (I and II) is to try to give fundamental concepts of quantum kinematics to q-deformed quantum spaces. Paper I introduces the relevant mathematical concepts. A short review of the basic ideas of q-deformed analysis is given. ... More

Braided products for quantum spacesSep 11 2005Attention is focused on quantum spaces of physical importance, i.e. Manin plane, q-deformed Euclidean space in three or four dimensions as well as q-deformed Minkowski space. There are algebra isomorphisms that allow to identify quantum spaces with commutative ... More

Noncommutative Plurisubharmonic Polynomials Part II: Local AssumptionsDec 30 2010Jan 14 2011We say that a symmetric noncommutative polynomial in the noncommutative free variables (x_1, x_2, ..., x_g) is noncommutative plurisubharmonic on a noncommutative open set if it has a noncommutative complex hessian that is positive semidefinite when evaluated ... More

Gravitational smoothing of kinks on cosmic string loopsSep 01 2016Sep 08 2016We analyze the effect of gravitational back reaction on cosmic string loops with kinks, which is an important determinant of the shape, and thus the potential observability, of string loops which may exist in the universe today. Kinks are not rounded ... More

Gravitational back reaction on piecewise linear cosmic string loopsSep 06 2016We calculate the metric and affine connection due to a piecewise linear cosmic string loop, and the effect of gravitational back reaction for the Garfinkle-Vachaspati loop with four straight segments. As expected, back reaction reduces the size of the ... More

Electromagnetic back-reaction from currents on a straight stringMay 08 2014Jul 07 2014Charge carriers moving at the speed of light along a straight, superconducting cosmic string carry with them a logarithmically divergent slab of electromagnetic field energy. Thus no finite local input can induce a current that travels unimpeded to infinity. ... More

Optical imaging of strain in two-dimensional crystalsMar 07 2019Strain engineering is widely used in material science to tune the (opto-)electronic properties of materials and enhance the performance of devices. Two-dimensional atomic crystals are a versatile playground to study the influence of strain, as they can ... More

Testing grain-surface chemistry in massive hot-core regionsFeb 02 2007Feb 12 2007A partial submillimeter line-survey was performed toward 7 high-mass young stellar objects (YSOs) aimed at detecting H2CO, CH3OH, CH2CO, CH3CHO, C2H5OH, HCOOH, HNCO and NH2CHO. In addition, other organic species such as CH3CN have been observed. The aim ... More

Machine Learning at ScaleFeb 25 2014It takes skill to build a meaningful predictive model even with the abundance of implementations of modern machine learning algorithms and readily available computing resources. Building a model becomes challenging if hundreds of terabytes of data need ... More

The hyperfine energy levels of alkali metal dimers: ground-state homonuclear molecules in magnetic fieldsOct 27 2008We investigate the hyperfine energy levels and Zeeman splittings for homonuclear alkali-metal dimers in low-lying rotational and vibrational states, which are important for experiments designed to produce quantum gases of deeply bound molecules. We carry ... More

On the interaction of NH($X^{3}Σ^{-}$) molecules with rubidium atoms: implications for sympathetic cooling and the formation of extremely polar moleculesJul 18 2003Jul 21 2003The Rb-NH interaction is investigated as a prototype for interactions between alkali metal atoms and stable molecules. For spin-aligned Rb and NH that interact on a quartet surface ($^4A''$), the interaction is relatively weak, with a well depth of 0.078 ... More

Molecular collisions in ultracold atomic gasesOct 24 2006It has recently become possible to form molecules in ultracold gases of trapped alkali metal atoms. Once formed, the molecules may undergo elastic, inelastic and reactive collisions. Inelastic and reactive collisions are particularly important because ... More

Stability and Complexity of Minimising Probabilistic AutomataApr 26 2014May 01 2014We consider the state-minimisation problem for weighted and probabilistic automata. We provide a numerically stable polynomial-time minimisation algorithm for weighted automata, with guaranteed bounds on the numerical error when run with floating-point ... More

Gravitational back-reaction near cosmic string kinks and cuspsAug 24 2018Aug 31 2018We find the leading-order effect of gravitational back-reaction on cosmic strings for points near kinks and cusps. Near a kink, the effect diverges as the inverse cube root of the distance to the kink, and acts in a direction transverse to the worldsheet. ... More

Racetrack Potentials and the de Sitter Swampland ConjecturesNov 13 2018Jan 15 2019We show that one can find de Sitter critical points (saddle points) in models of flux compactification of Type IIB String Theory without any uplifting terms and in the presence of several moduli. We demonstrate this by giving explicit examples following ... More

Radio detections of the neutron star X-ray binaries 4U 1820-30 and Ser X-1 in soft X-ray statesFeb 25 2004We present the analysis of simultaneous X-ray (RXTE) and radio (VLA) observations of two atoll-type neutron star X-ray binaries: 4U 1820-30 and Ser X-1. Both sources were steadily in the soft (banana) X-ray state during the observations. We have detected ... More

Reactions between cold methyl halide molecules and alkali-metal atomsOct 16 2013Nov 14 2013We investigate the potential energy surfaces and activation energies for reactions between methyl halide molecules CH$_{3}X$ ($X$ = F, Cl, Br, I) and alkali-metal atoms $A$ ($A$ = Li, Na, K, Rb) using high-level {\it ab initio} calculations. We examine ... More

List Decoding of Locally Repairable CodesJan 12 2018May 08 2018We show that locally repairable codes (LRCs) can be list decoded efficiently beyond the Johnson radius for a large range of parameters by utilizing the local error correction capabilities. The new decoding radius is derived and the asymptotic behavior ... More

Cosmic Rays from Gamma Ray Bursts in the GalaxyApr 06 2005Jun 16 2005The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations of cosmic rays ... More

Ultracold hydrogen atoms: a versatile coolant to produce ultracold moleculesMay 27 2013Oct 19 2013We show theoretically that ultracold hydrogen atoms have very favorable properties for sympathetic cooling of molecules to microkelvin temperatures. We calculate the potential energy surfaces for spin-polarized interactions of H atoms with the prototype ... More

The prospects of forming ultracold molecules in $^2Σ$ states by magnetoassociation of alkali-metal atoms with YbApr 29 2013We explore the feasibility of producing ultracold diatomic molecules with nonzero electric and magnetic dipole moments by magnetically associating two atoms, one with zero electron spin and one with nonzero spin. Feshbach resonances arise through the ... More

Multichannel Quantum Defect Theory for cold molecular collisions with a strongly anisotropic potential energy surfaceDec 20 2012We show that multichannel quantum defect theory (MQDT) can be applied successfully as an efficient computational method for cold molecular collisions in Li+NH, which has a deep and strongly anisotropic interaction potential. In this strongly coupled system, ... More

Production of ultracold NH molecules by sympathetic cooling with MgJun 29 2009Jun 30 2009We carry out calculations on $M$-changing collisions of NH ($^3\Sigma^-$) molecules in magnetically trappable states using a recently calculated potential energy surface. We show that elastic collision rates are much faster than inelastic rates for a ... More

The prospects for producing ultracold NH$_3$ molecules by sympathetic cooling: a survey of interaction potentialsMay 12 2008We investigate the possibility of producing ultracold NH3 molecules by sympathetic cooling in a bath of ultracold atoms. We consider the interactions of NH3 with alkali-metal and alkaline-earth atoms, and with Xe, using ab initio coupled-cluster calculations. ... More

Low-energy collisions of NH3 and ND3 with ultracold Rb atomsFeb 26 2009May 19 2009We carry out quantum inelastic scattering calculations of collisions of Rb atoms with inverting NH3 and ND3 molecules in the energy range between 0 and 100 cm-1, which are important for experiments using velocity-controlled molecular beams to probe scattering ... More

Fast Operations on Linearized Polynomials and their Applications in Coding TheoryDec 21 2015This paper considers fast algorithms for operations on linearized polynomials. Among these results are fast algorithms for division of linearized polynomials, $q$-transform, multi-point evaluation, computing minimal subspace polynomials and interpolation. ... More

Vector Network Coding Based on Subspace Codes Outperforms Scalar Linear Network CodingDec 20 2015May 15 2016This paper considers vector network coding solutions based on rank-metric codes and subspace codes. The main result of this paper is that vector solutions can significantly reduce the required field size compared to the optimal scalar linear solution ... More

Automatic Classification of Roof Shapes for Multicopter Emergency Landing Site SelectionFeb 17 2018Geographic information systems (GIS) now provide accurate maps of terrain, roads, waterways, and building footprints and heights. Aircraft, particularly small unmanned aircraft systems, can exploit additional information such as building roof structure ... More

User Manual for MOLSCAT, BOUND and FIELD: programs for quantum scattering properties and bound states of interacting pairs of atoms and moleculesMar 15 2019MOLSCAT is a general-purpose package for performing non-reactive quantum scattering calculations for atomic and molecular collisions using coupled-channel methods. Simple atom-molecule and molecule-molecule collision types are coded internally and additional ... More

The planetary nebula Abell 48 and its [WN] nucleusJan 17 2013Mar 06 2014We have conducted a detailed multi-wavelength study of the peculiar nebula Abell 48 and its central star. We classify the nucleus as a helium-rich, hydrogen-deficient star of type [WN4-5]. The evidence for either a massive WN or a low-mass [WN] interpretation ... More

The WIRED Survey I: A Bright IR Excess Due to Dust Around the Heavily Polluted White Dwarf GALEX J193156.8+011745Dec 22 2010With the launch of the Wide-Field Infrared Survey Explorer (WISE), a new era of detecting planetary debris around white dwarfs has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED Survey will be sensitive to substellar ... More

Unraveling the cooling trend of the Soft Gamma Repeater, SGR 1627-41Sep 03 2003Oct 27 2003SGR 1627-41 was discovered in 1998 after a single active episode which lasted \~6 weeks. We report here our monitoring results of the decay trend of the persistent X-ray luminosity of the source during the last 5 years. We find an initial temporal power ... More

Ab initio potential energy surfaces, bound states and electronic spectrum of the Ar-SH complexOct 11 2006New ab initio potential energy surfaces for the doublet pi ground electronic state of the Ar-SH complex are presented, calculated at the RCCSD(T)/aug-cc-pV5Z level. Weakly bound rotation-vibration levels are calculated using coupled-channel methods that ... More

Bounds and Constructions for Multi-Symbol Duplication Error Correcting CodesJul 08 2018Sep 19 2018In this paper, we study codes correcting $t$ duplications of $\ell$ consecutive symbols. These errors are known as tandem duplication errors, where a sequence of symbols is repeated and inserted directly after its original occurrence. Using sphere packing ... More

Creating Feshbach resonances for ultracold molecule formation with radiofrequency fieldsJun 30 2016Aug 09 2016We show that radiofrequency (RF) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of $^{39}$K+$^{133}$Cs, where ... More

How to Fool Radiologists with Generative Adversarial Networks? A Visual Turing Test for Lung Cancer DiagnosisOct 26 2017Jan 09 2018Discriminating lung nodules as malignant or benign is still an underlying challenge. To address this challenge, radiologists need computer aided diagnosis (CAD) systems which can assist in learning discriminative imaging features corresponding to malignant ... More

Modulus and Poincaré inequalities on non-self-similar Sierpinski carpetsJan 17 2012Feb 01 2013A carpet is a metric space homeomorphic to the Sierpinski carpet. We characterize, within a certain class of examples, non-self-similar carpets supporting curve families of nontrivial modulus and supporting Poincar\'e inequalities. Our results yield new ... More

Conformal surface embeddings and extremal lengthJul 19 2015May 03 2017Given two Riemann surfaces with boundary and a homotopy class of topological embeddings between them, there is a conformal embedding in the homotopy class if and only if the extremal length of every simple multi-curve is decreased under the embedding. ... More

A New Way to Conserve Total Energy for Eulerian Hydrodynamic Simulations with Self-GravityAug 08 2012Oct 01 2012We propose a new method to conserve the total energy to round-off error in grid-based codes for hydrodynamic simulations with self-gravity. A formula for the energy flux due to the work done by the the self-gravitational force is given, so the change ... More

Simplicial and Cellular TreesJun 22 2015Much information about a graph can be obtained by studying its spanning trees. On the other hand, a graph can be regarded as a 1-dimensional cell complex, raising the question of developing a theory of trees in higher dimension. As observed first by Bolker, ... More

Frequency of Sobolev dimension distortion of horizontal subgroups of Heisenberg groupsMar 28 2013We study the behavior of Sobolev mappings defined on the Heisenberg groups with respect to a foliation by left cosets of a horizontal homogeneous subgroup. We quantitatively estimate, in terms of Euclidean Hausdorff dimension, the size of the set of cosets ... More

Cuts and flows of cell complexesJun 27 2012Sep 30 2014We study the vector spaces and integer lattices of cuts and flows associated with an arbitrary finite CW complex, and their relationships to group invariants including the critical group of a complex. Our results extend to higher dimension the theory ... More

Optimizing and Evaluating Transient Gradual TypingFeb 20 2019Gradual typing enables programmers to combine static and dynamic typing in the same language. However, ensuring a sound interaction between the static and dynamic parts can incur significant runtime cost. In this paper, we perform a detailed performance ... More

AbPress: Flexing Partial-Order Reduction and AbstractionOct 22 2014Partial-order reduction (POR) and lazy abstraction with interpolants are two complementary techniques that have been successfully employed to make model checking tools for concurrent programs effective. In this work, we present AbPress - Abstraction-based ... More

Locality in Crisscross Error CorrectionJun 19 2018Sep 04 2018The cover metric is suitable for describing the resilience against correlated errors in arrays, in particular crisscross errors, which makes it interesting for applications such as distributed data storage (DDS). In this work, we consider codes designed ... More

The ionized gas in the central region of NGC 5253: 2D mapping of the physical and chemical propertiesJun 11 2012ABRIDGED: NGC5253 was previously studied by our group with the aim to elucidate in detail the starburst interaction processes. Some open issues regarding the 2D structure of the main properties of the ionized gas remain to be addressed. Using IFS data ... More

Long range intermolecular forces in triatomic systems: connecting the atom-diatom and atom-atom-atom representationsMay 19 2005The long-range forces that act between three atoms are analysed in both atom-diatom and atom-atom-atom representations. Expressions for atom-diatom dispersion coefficients are obtained in terms of 3-body nonadditive coefficients. The anisotropy of atom-diatom ... More

Compressed Sensing and Reconstruction of Unstructured Mesh DatasetsAug 25 2015Exascale computing promises quantities of data too large to efficiently store and transfer across networks in order to be able to analyze and visualize the results. We investigate Compressive Sensing (CS) as a way to reduce the size of the data as it ... More

A group theoretical route to deterministic Weyl points in chiral photonic latticesJun 19 2017Classical topological phases derived from point degeneracies in photonic bandstructures show intriguing and unique behaviour. Previously identified exceptional points are based on accidental degeneracies and subject to engineering on a case-by-case basis. ... More

Tracking yeast pheromone receptor Ste2 endocytosis using fluorogen-activating protein taggingJan 21 2019To observe internalization of the yeast pheromone receptor Ste2 by fluorescence microscopy in live cells in real time, we visualized only those molecules present at the cell surface at the time of agonist engagement (rather than the total cellular pool) ... More

Double Threshold DigraphsFeb 21 2017Jun 26 2018A semiorder is a model of preference relations where each element $x$ is associated with a utility value $\alpha(x)$, and there is a threshold $t$ such that $y$ is preferred to $x$ iff $\alpha(y) > \alpha(x)+t$. These are motivated by the notion that ... More

Quasiconformal mappings that highly distort dimensions of many parallel linesJan 26 2016We construct a quasiconformal mapping of $n$-dimensional Euclidean space, $n \geq 2$, that simultaneously distorts the Hausdorff dimension of a nearly maximal collection of parallel lines by a given amount. This answers a question of Balogh, Monti, and ... More

Effect of quantum confinement on exciton-phonon interactionsJul 04 2002Sep 16 2002We investigate the homogeneous linewidth of localized type-I excitons in type-II GaAs/AlAs superlattices. These localizing centers represent the intermediate case between quasi-two-dimensional (Q2D) and quasi-zero-dimensional localizations. The temperature ... More

Optimized Multichannel Quantum Defect Theory for cold molecular collisionsJun 26 2012Multichannel quantum defect theory (MQDT) can provide an efficient alternative to full coupled-channel calculations for low-energy molecular collisions. However, the efficiency relies on interpolation of the Y matrix that encapsulates the short-range ... More

Ultracold RbSr molecules can be formed by magnetoassociationJun 15 2010We investigate the interactions between ultracold alkali metal atoms and closed-shell atoms using electronic structure calculations on the prototype system Rb+Sr. There are molecular bound states that can be tuned across atomic thresholds with magnetic ... More

Dramatic reductions in inelastic cross sections for ultracold collisions near Feshbach resonancesAug 14 2009We show that low-energy inelastic cross sections can decrease as well as increase in the vicinity of a zero-energy Feshbach resonance. When an external field is used to tune across such a resonance, the real and imaginary parts of the scattering length ... More

Observation of the Second Triatomic Resonance in Efimov's ScenarioFeb 25 2014Apr 27 2014We report the observation of a three-body recombination resonance in an ultracold gas of cesium atoms at a very large negative value of the $s$-wave scattering length. The resonance is identified as the second triatomic Efimov resonance, which corresponds ... More

A Novel Motion Detection Method Resistant to Severe Illumination ChangesDec 11 2016Mar 15 2018Recently, there has been a considerable attention given to the motion detection problem due to the explosive growth of its applications in video analysis and surveillance systems. While the previous approaches can produce good results, an accurate detection ... More

Cellular spanning trees and Laplacians of cubical complexesAug 13 2009May 05 2010We prove a Matrix-Tree Theorem enumerating the spanning trees of a cell complex in terms of the eigenvalues of its cellular Laplacian operators, generalizing a previous result for simplicial complexes. As an application, we obtain explicit formulas for ... More

Simplicial matrix-tree theoremsFeb 19 2008Aug 21 2008We generalize the definition and enumeration of spanning trees from the setting of graphs to that of arbitrary-dimensional simplicial complexes $\Delta$, extending an idea due to G. Kalai. We prove a simplicial version of the Matrix-Tree Theorem that ... More

Dimension distortion by Sobolev mappings in foliated metric spacesJan 25 2013Jul 09 2013We quantify the extent to which a supercritical Sobolev mapping can increase the dimension of subsets of its domain, in the setting of metric measure spaces supporting a Poincar\'e inequality. For foliations of a metric space X defined by a David--Semmes ... More

Dimer chains in waveguide quantum electrodynamicsAug 29 2018We examine the propagation of single photons in periodic and disordered dimer chains coupled to one-dimensional chiral and bidirectional waveguides. Each dimer is composed of two dipole-coupled atoms. In the disordered setting, we separately treat two ... More

Statistical Image Reconstruction for High-Throughput Thermal Neutron Computed TomographyJun 07 2018Sep 25 2018Neutron Computed Tomography (CT) is an increasingly utilised non-destructive analysis tool in material science, palaeontology, and cultural heritage. With the development of new neutron imaging facilities (such as DINGO, ANSTO, Australia) new opportunities ... More

Counting Roots of Polynomials over $\mathbb{Z}/p^2\mathbb{Z}$Aug 15 2017Dec 12 2017Until recently, the only known method of finding the roots of polynomials over prime power rings, other than fields, was brute force. One reason for this is the lack of a division algorithm, obstructing the use of greatest common divisors. Fix a prime ... More

An infinite-temperature limit for a quantum scattering processJan 04 2008Dec 12 2008We study a quantum dynamical semigroup driven by a Lindblad generator with a deterministic Schr\"odinger part and a noisy Poission-timed scattering part. The dynamics describes the evolution of a test particle in $\R^{n}$, $n=1,2,3$, immersed in a gas, ... More

The topology of the space of J-holomorphic maps to CP^2Oct 27 2012Nov 05 2014The purpose of this paper is to generalize a theorem of Segal from [Seg79] proving that the space of holomorphic maps from a Riemann surface to a complex projective space is homology equivalent to the corresponding space of continuous maps through a range ... More

The Derived Marsden-Weinstein Quotient is SymplecticMay 29 2012Let $(X,\omega_X)$ be a derived scheme with a 0-symplectic form and suppose there is a Hamiltonian $G$-action with a moment map for $G$ a reductive group. We prove, under no further assumptions, that symplectic reduction along any coadjoint orbit in the ... More

A limit theorem to a time-fractional diffusionOct 04 2011Feb 12 2013We prove a limit theorem for an integral functional of a Markov process. The Markovian dynamics is characterized by a linear Boltzmann equation modeling a one-dimensional test particle of mass $\lambda^{-1}\gg 1$ in an external periodic potential and ... More

On the Geometric Interpretation of the Complex Fourier Transforms of a Class of Exponential FunctionsJan 21 2009A class of complex Fourier Transforms of exponential functions which have all their zeros on the real line is explored from a geometric perspective. These transforms belong to the Laguerre - Polya class, and it is proved that all the zeros are simple. ... More

Stability and bifurcation of equilibria for the axisymmetric averaged mean curvature flowNov 08 2012Nov 09 2012We study the averaged mean curvature flow, also called the volume preserving mean curvature flow, in the particular setting of axisymmetric surfaces embedded in R^3 satisfying periodic boundary conditions. We establish analytic well--posedness of the ... More

Generalized covering space theoriesAug 20 2015In this paper, we unify various approaches to generalized covering space theory by introducing a categorical framework in which coverings are defined purely in terms of unique lifting properties. For each category $\mathcal{C}$ of path-connected spaces ... More

Quadratic forms representing all odd positive integersNov 03 2011Nov 06 2013We consider the problem of classifying all positive-definite integer-valued quadratic forms that represent all positive odd integers. Kaplansky considered this problem for ternary forms, giving a list of 23 candidates, and proving that 19 of those represent ... More

Radio scintillation of gamma-ray-burst afterglowsJun 09 1997Stars twinkle to the eye through atmospheric turbulence, but planets, because of their larger angular size, do not. Similarly, scintillation due to the local interstellar medium will modulate the radio flux of gamma-ray-burst afterglows and may permit ... More

Deformations of vector bundles on coisotropic subvarieties via the Atiyah classOct 18 2010Using the Atiyah class we give a criterion for a vector bundle on a coisotropic subvariety, $Y$, of an algebraic Poisson variety $X$ to admit a first and second order noncommutative deformation. We also show noncommutative deformations of a vector bundle ... More

Betting on Quantum ObjectsJul 20 2017Jul 28 2017Dutch book arguments have been applied to beliefs about the outcomes of measurements of quantum systems, but not to beliefs about quantum objects prior to measurement. In this paper, we prove a quantum version of the probabilists' Dutch book theorem that ... More

Probabilism for Stochastic TheoriesSep 09 2018I defend an analog of probabilism that characterizes rationally coherent estimates for chances. Specifically, I demonstrate the following accuracy-dominance result for stochastic theories in the C*-algebraic framework: supposing an assignment of chance ... More

Hadron Structure from Lattice QCDDec 15 2014Recent progress in lattice QCD calculations of nucleon structure will be presented. Calculations of nucleon matrix elements and form factors have long been difficult to reconcile with experiment, but with advances in both methodology and computing resources, ... More

Nilpotence in E_n AlgebrasJul 04 2017Nilpotence in the homotopy of $\mathbb{E}_\infty$-ring spectra is detected by the classical $H\mathbb{Z}$-Hurewicz homomorphism. Inspired by questions of Mathew, Noel, and Naumann, we investigate the extent to which this criterion holds in the homotopy ... More

The intermediate age population of the Galactic haloMar 13 2019We have learned recently that the inner halo of the Milky Way contains a kinematically coherent component (Gaia-Enceladus) from a significant merger 10 Gyrs ago. By contrast the inner halo (defined to exclude the Magellanic Stream) contains no similar ... More

A completely integrable system on $G_2$ coadjoint orbitsMay 05 2016May 23 2016We construct a Gelfand-Zeitlin system on a one-parameter family of $G_2$ coadjoint orbits that are multiplicity-free Hamiltonian $SU(3)$-spaces. Using this system we prove a lower bound for the Gromov width of these orbits. This lower bound agrees with ... More

Next Generation Deep 2 micron SurveySep 18 2012There is a major opportunity for the KDUST 2.5m telescope to carry out the next generation IR survey. A resolution of 0.2 arcsec is obtainable from Dome A over a wide field. This opens a unique discovery space during the 2015-2025 decade. A next generation ... More

A far-from-CMC existence result for the constraint equations on manifolds with ends of cylindrical typeJun 03 2013Jul 25 2013We extend the study of the vacuum Einstein constraint equations on manifolds with ends of cylindrical type initiated by Chru\'sciel and Mazzeo by finding a class of solutions to the fully coupled system on such manifolds. We show that given a Yamabe positive ... More

On identities involving the sixth order mock theta functionsNov 13 2009Nov 16 2009We present q-series proofs of four identities involving sixth order mock theta functions from Ramanujan's lost notebook. We also show how Ramanujan's identities can be used to give a quick proof of four sixth order identities of Berndt and Chan.

Measuring the impact of input data on energy consumption of softwareNov 10 2014The amount of energy consumed during the execution of software, and the ability to predict future consumption, is an important factor in the design of embedded electronic systems. In this technical report I examine factors in the execution of software ... More

A cocomplete but not complete abelian categoryMay 27 2018An example of a cocomplete abelian category that is not complete is constructed.

Proximity inductive dimension and Brouwer dimension agree on compact Hausdorff spacesMar 04 2019In this paper we show that the proximity inductive dimension defined by Isbell agrees with the Brouwer dimension originally described by Brouwer on the class of compact Hausdorff spaces. Consequently, Fedorchuk's example of a compact Hausdorff space whose ... More

Concerning thermal tides on hot JupitersJan 21 2009By analogy with a mechanism proposed by Gold and Soter to explain the retrograde rotation of Venus, Arras and Socrates suggest that thermal tides may excite hot jovian exoplanets into nonsynchronous rotation, and perhaps also noncircular orbits. It is ... More

Weighing the "Heaviest" Polya UrnFeb 13 2014Jun 29 2014In the classical Polya urn problem, one begins with $d$ bins, each containing one ball. Additional balls arrive one at a time, and the probability that an arriving ball is placed in a given bin is proportional to $m^\gamma$, where $m$ is the number of ... More

Integers represented by positive-definite quadratic forms and Petersson inner productsFeb 09 2018Let $Q$ be a positive-definite quaternary quadratic form with integer coefficients. We study the problem of giving bounds on the largest positive integer $n$ that is locally represented by $Q$ but not represented. Assuming that $n$ is relatively prime ... More

Compressed words and automorphisms in fully residually free groupsAug 05 2009Oct 21 2009We show that the compressed word problem in a finitely-generated fully residually free group (F -group) is decidable in polynomial time, and use the result to show that the word problem in the automorphism group of such a group is decidable in polynomial ... More

Topological Monodromy of an Integrable Heisenberg Spin ChainNov 25 2014Jul 31 2015We investigate topological properties of a completely integrable system on $S^2\times S^2 \times S^2$ which was recently shown to have a Lagrangian fiber diffeomorphic to $\mathbb{R} P^3$ not displaceable by a Hamiltonian isotopy [Oakley J., Ph.D. Thesis, ... More

Homological stability properties of spaces of rational J-holomorphic curves in P^2Oct 07 2011In a well known work [Se], Graeme Segal proved that the space of holomorphic maps from a Riemann surface to a complex projective space is homology equivalent to the corresponding continuous mapping space through a range of dimensions increasing with degree. ... More

Uniform distribution and algorithmic randomnessMar 19 2012Jul 14 2012A seminal theorem due to Weyl states that if (a_n) is any sequence of distinct integers, then, for almost every real number x, the sequence (a_n x) is uniformly distributed modulo one. In particular, for almost every x in the unit interval, the sequence ... More

Modeling sympathetic cooling of molecules by ultracold atomsAug 17 2015Nov 11 2015We model sympathetic cooling of ground-state CaF molecules by ultracold Li and Rb atoms. The molecules are moving in a microwave trap, while the atoms are trapped magnetically. We calculate the differential elastic cross sections for CaF-Li and CaF-Rb ... More

Work Issues in Software EngineeringMar 11 2013Using data from a web-based survey of software developers, the author attempts to determine root causes of "death march" projects and excessive work hours in the software industry in relation to company practices and management. Special emphasis is placed ... More

Open subgroups of free topological groupsSep 25 2012Feb 01 2013The theory of covering spaces is often used to prove the Nielsen-Schreier theorem, which states that every subgroup of a free group is free. We apply the more general theory of semicovering spaces to obtain analogous subgroup theorems for topological ... More

High Speed Interconnects and Parallel Software Libraries: Enabling Technologies for the NVOSep 08 2000The NVOs core data mining and archive federation activities are heavily dependent on the underlying data pipeline software necessary to translate the raw data into scientifically relevant source detections. The data pipeline software dictates: the raw ... More