Results for "Ian A. Bond"

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A High-Resolution Spectrum of the Highly Magnified Bulge G-Dwarf MOA-2006-BLG-099SJan 14 2008We analyze a high-resolution spectrum of a microlensed G-dwarf in the Galactic bulge, acquired when the star was magnified by a factor of 110. We measure a spectroscopic temperature, derived from the wings of the Balmer lines, that is the same as the ... More
Clues to the Metallicity Distribution in the Galactic Bulge: Abundances in MOA-2008-BLG310 and MOA-2008-BLG311Apr 13 2009May 08 2009We present abundance analyses based on high dispersion and high signal-to-noise ratio Magellan spectra of two highly microlensed Galactic bulge stars in the region of the main sequence turnoff with Teff ~ 5650 K. We find that MOA-2008-BLG310 has [Fe/H]= ... More
A Second Method to Photometrically Align Multi-Site Microlensing Light Curves: Source Color in Planetary Event MOA-2007-BLG-192Oct 12 2009At present, microlensing light curves from different telescopes and filters are photometrically aligned by fitting them to a common model. We present a second method based on photometry of common field stars. If two spectral responses are similar (or ... More
Better-than-expert detection of early coronary artery occlusion from 12 lead electrocardiograms using deep learningMar 11 2019Mar 13 2019Early diagnosis of acute coronary artery occlusion based on electrocardiogram (ECG) findings is essential for prompt delivery of primary percutaneous coronary intervention. Current ST elevation (STE) criteria are specific but insensitive. Consequently, ... More
The Demographics of Extrasolar Planets Beyond the Snow Line with Ground-based Microlensing SurveysMar 04 2009In the currently-favored paradigm of planet formation, the location of the snow line in the protoplanetary disk plays a crucial role. Determining the demographics of planets beyond the snow line of stars of various masses is thus essential for testing ... More
Direct Extragalactic Distance Determination Using X-Ray ScatteringJul 20 2004We examine the feasibility of using dust-scattered X-rays for direct determination of distances to nearby galaxies with bright background AGNs, QSOs, or GRBs. We show how the Chandra X-Ray Observatory could be used to determine the distance to M31 to ... More
Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani BSep 01 2017The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD's mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low ... More
Microlensing Results Challenge the Core Accretion Runaway Growth Scenario for Gas GiantsDec 31 2018We compare the planet-to-star mass-ratio distribution measured by gravitational microlensing to core accretion theory predictions from population synthesis models. The core accretion theory's runaway gas accretion process predicts a dearth of intermediate-mass ... More
Weyl groups and Elliptic Solutions of the WDVV equationsFeb 04 2008Nov 04 2009A functional ansatz is developed which gives certain elliptic solutions of the Witten-Dijkgraaf-Verlinde-Verlinde (or WDVV) equation. This is based on the elliptic trilogarithm function introduced by Beilinson and Levin. For this to be a solution results ... More
Direct Exoplanet Investigation using Interstellar Space ProbesJul 04 2017Jul 08 2017Experience in exploring our own solar system has shown that direct investigation of planetary bodies using space probes invariably yields scientific knowledge not otherwise obtainable. In the case of exoplanets, such direct investigation may be required ... More
The Moon as a Recorder of Nearby SupernovaeAug 13 2016The lunar geological record is expected to contain a rich record of the galactic environment of the Solar System, including records of nearby (i.e. less than a few tens of parsecs) supernova explosions. This record will be composed of two principal components: ... More
The Astronomical, Astrobiological and Planetary Science Case for Interstellar SpaceflightAug 28 2010A review is presented of the scientific benefits of rapid (v >= 0.1c) interstellar spaceflight. Significant benefits are identified in the fields of interstellar medium studies, stellar astrophysics, planetary science and astrobiology. In the latter three ... More
Parsimony, model adequacy and periodic correlation in forecasting time seriesNov 04 2016The merits of the modelling philosophy of Box \& Jenkins (1970) are illustrated with a summary of our recent work on seasonal river flow forecasting. Specifically, this work demonstrates that the principle of parsimony, which has been questioned by several ... More
Differential and Functional Identities for the Elliptic TrilogarithmMar 13 2009When written in terms of $\vartheta$-functions, the classical Frobenius-Stickelberger pseudo-addition formula takes a very simple form. Generalizations of this functional identity are studied, where the functions involved are derivatives (including derivatives ... More
Lunar Resources: A ReviewOct 25 2014There is growing interest in the possibility that the resource base of the Solar System might in future be used to supplement the economic resources of our own planet. As the Earth's closest celestial neighbour, the Moon is sure to feature prominently ... More
Stapledon's Interplanetary Man: A Commonwealth of Worlds and the Ultimate Purpose of Space ColonisationJul 06 2012In his 1948 lecture to the British Interplanetary Society, Olaf Stapledon considered the ultimate purpose of colonising other worlds. Having examined the possible motivations arising from improved scientific knowledge and access to extraterrestrial raw ... More
A construction of Multidimensional Dubrovin-Novikov BracketsJun 27 2018A method for the construction of classes of examples of multi-dimensional, multi-component Dubrovin-Novikov brackets of hydrodynamic type is given. This is based on an extension of the original construction of Gelfand and Dorfman which gave examples of ... More
Competitive Accretion in Clusters and the IMFJan 26 2000Observations have revealed that most stars are born in clusters. As these clusters typically contain more mass in gas than in stars, accretion can play an important role in determining the final stellar masses. Numerical simulations of gas accretion in ... More
Spiral arm triggering of star formationNov 07 2006We present numerical simulations of the passage of clumpy gas through a galactic spiral shock, the subsequent formation of giant molecular clouds (GMCs) and the triggering of star formation. The spiral shock forms dense clouds while dissipating kinetic ... More
The Formation of Massive Binary StarsJan 13 2005The formation of massive stars in close binary systems is complicated due to their high radiation pressure, the crowded environment and the expected minimum separation for fragmentation being many times greater than the orbital separation. I discuss how ... More
Jordan manifolds and dispersionless KdV equationsOct 01 2000Multicomponent KdV-systems are defined in terms of a set of structure constants and, as shown by Svinolupov, if these define a Jordan algebra the corresponding equations may be said to be integrable, at least in the sense of having higher-order symmetries, ... More
Widening Perspectives: The Intellectual and Social Benefits of Astrobiology (Regardless of Whether Extraterrestrial Life is Discovered or Not)Mar 18 2017Astrobiology is usually defined as the study of the origin, evolution, distribution, and future of life in the universe. As such it is inherently interdisciplinary and cannot help but engender a worldview infused by cosmic and evolutionary perspectives. ... More
Project Icarus: Preliminary Thoughts on the Selection of Probes and Instruments for an Icarus-style Interstellar MissionJun 04 2016In this paper we outline the range of probes and scientific instruments that will be required in order for Icarus to fulfill its scientific mission of exploring a nearby star, its attendant planetary system, and the intervening interstellar medium. Based ... More
Science enabled by a Moon VillageJun 20 2017A human-robotic "Moon Village" would offer significant scientific opportunities by providing an infrastructure on the lunar surface. An analogy would be the way in which human outposts in Antarctica facilitate research activities across multiple scientific ... More
Hopping between Random Locations: Spectrum and InstantonJun 22 2000Euclidean random matrices appear in a broad class of physical problems involving disorder. The problem of determining their spectra can be mapped, using the replica method, into the study of a scalar field theory with an interaction of the type e^(psi^2). ... More
Hyperbolic decay time seriesNov 02 2016Hyperbolic decay time series such as, fractional Gaussian noise (FGN) or fractional autoregressive moving-average (FARMA) process, each exhibit two distinct types of behaviour: strong persistence or antipersistence. Beran (1994) characterized the family ... More
Improved spread-location visualizationNov 04 2016The spread-location plot has often been used as a diagnostic plot suitable for many types of fitted statistical models. The spread-location plot which plots the absolute residual or square-root absolute residual versus fitted value along with a robust ... More
Necessary and Sufficient Condition for Nonsingular Fisher Information Matrix in ARMA ModelsNov 04 2016It is demonstrated that a necessary and sufficient condition that the Fisher information matrix of an ARMA model be nonsingular is that the model not be redundant, that is, the autoregressive and moving-average polynomials do not share common roots.
Differential Morphology Between Rest-frame Optical and UV Emission from 1.5 < z < 3 Star-forming GalaxiesOct 07 2010Jan 06 2011We present the results of a comparative study of the rest-frame optical and rest-frame ultraviolet morphological properties of 117 star-forming galaxies (SFGs), including BX, BzK, and Lyman break galaxies with B<24.5, and 15 passive galaxies in the region ... More
The Absorbers Toward CSO 118: Superclustering at {z~3}, or an Intrinsic Absorption Complex?May 04 2001We present two low resolution (R~1300) high signal-to-noise spectra (Wr,lim~50mA) of the quasar CSO 118 (zem=2.97) taken with the Hobby-Eberly Telescope Marcario Low Resolution Spectrograph. We detect eight absorbers selected by the CIV 1548,1550 absorption ... More
The Impact of baryonic physics on the kinetic Sunyaev-Zel'dovich EffectOct 08 2017Nov 30 2017Poorly understood "baryonic physics" impacts our ability to predict the power spectrum of the kinetic Sunyaev-Zel'dovich (kSZ) effect. We study this in one sample high resolution simulation of galaxy formation and feedback, Illustris. The high resolution ... More
Photon impact factor and $k_T$-factorization for DIS in the next-to-leading orderJul 16 2012Jul 27 2014The photon impact factor for the BFKL pomeron is calculated in the next-to-leading order (NLO) approximation using the operator expansion in Wilson lines. The result is represented as a NLO $k_T$-factorization formula for the structure functions of small-$x$ ... More
Conformal invariance of TMD rapidity evolutionMay 22 2019We discuss conformal properties of TMD operators and present the result of the conformal rapidity evolution of TMD operators in the Sudakov region.
Nonleptonic Two-Body Decays of D Mesons in Broken SU(3)Feb 10 1995Decays of the D mesons to two pseudoscalars, to two vectors, and to pseudoscalar plus vector are discussed in the context of broken flavor SU(3). A few assumptions are used to reduce the number of parameters. Amplitudes are fit to the available data, ... More
Fitting MA(q) Models in the Closed Invertible RegionNov 15 2016The use of reparameterization in the maximization of the likelihood function of the MA(q) model is discussed. A general method for testing for the presence of a parameter estimate on the boundary of an MA(q) model is presented. This test is illustrated ... More
NLO evolution of color dipolesOct 23 2007The small-$x$ deep inelastic scattering in the saturation region is governed by the non-linear evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the BK equation for the evolution of color dipoles. In the next-to-leading ... More
On modular mod $\ell$ Galois representations with exceptional imagesNov 06 2003We give a parametrization of the possible Serre invariants $(N,k,\nu)$ of modular mod $\ell$ Galois representations of the exceptional types $A_4$, $S_4$, $A_5$, in terms of local data attached to the fields cut out by the associated projective representations. ... More
The mass-Peak Patch algorithm for fast generation of deep all-sky dark matter halo catalogues and its N-Body validationOct 17 2018We present a detailed description and validation of our massively-parallel update to the mass-Peak Patch method, a fully predictive initial-space algorithm to quickly generate dark matter halo catalogues in very large cosmological volumes. We perform ... More
On the detection of superdiffusive behaviour in time seriesJul 25 2016Nov 17 2016We present a new method for detecting superdiffusive behaviour and for determining rates of superdiffusion in time series data. Our method applies equally to stochastic and deterministic time series data (with no prior knowledge required of the nature ... More
On the Implementation of the 0-1 Test for ChaosJun 08 2009In this paper we address practical aspects of the implementation of the 0-1 test for chaos in deterministic systems. In addition, we present a new formulation of the test which significantly increases its sensitivity. The test can be viewed as a method ... More
Primordial triples and collisions of massive starsJan 29 2013Massive stars are known to have a high multiplicity, with examples of higher order multiples among the nearest and best studied objects. In this paper we study hierarchical multiple systems (an inner binary as a component of a wider binary) of massive ... More
Limits on initial mass segregation in young clustersMar 23 2009Mar 24 2009Mass segregation is observed in many star clusters, including several that are less than a few Myr old. Timescale arguments are frequently used to argue that these clusters must be displaying primordial segregation, because they are too young to be dynamically ... More
The IR stability of de Sitter QFT: Physical initial conditionsApr 21 2011This work uses Lorentz-signature in-in perturbation theory to analyze the late-time behavior of correlators in time-dependent interacting massive scalar field theory in de Sitter space. We study a scenario recently considered by Krotov and Polyakov in ... More
On the detection of superdiffusive behaviour in time seriesJul 25 2016Dec 21 2016We present a new method for detecting superdiffusive behaviour and for determining rates of superdiffusion in time series data. Our method applies equally to stochastic and deterministic time series data (with no prior knowledge required of the nature ... More
On the stability of plane Couette-Poiseuille flow with uniform cross-flowMar 11 2010We present a detailed study of the linear stability of plane Couette-Poiseuille flow in the presence of a cross-flow. The base flow is characterised by the cross flow Reynolds number, $R_{inj}$ and the dimensionless wall velocity, $k$. Squire's transformation ... More
On higher spin symmetries in de Sitter QFTsNov 20 2015Mar 03 2016We consider the consequences of global higher-spin symmetries in quantum field theories on a fixed de Sitter background of spacetime dimension $D \ge 3$. These symmetries enhance the symmetry group associated with the isometries of the de Sitter background ... More
High-energy amplitudes in N=4 SYM in the next-to-leading orderNov 27 2009The high-energy behavior of the N=4 SYM amplitudes in the Regge limit can be calculated order by order in perturbation theory using the high-energy operator expansion in Wilson lines. At large $N_c$, a typical four-point amplitude is determined by a single ... More
Improved multivariate portmanteau testNov 02 2016A new portmanteau diagnostic test for vector autoregressive moving average (VARMA) models that is based on the determinant of the standardized multivariate residual autocorrelations is derived. The new test statistic may be considered an extension of ... More
On the Validity of the 0-1 Test for ChaosJun 08 2009In this paper, we present a theoretical justification of the 0-1 test for chaos. In particular, we show that with probability one, the test yields 0 for periodic and quasiperiodic dynamics, and 1 for sufficiently chaotic dynamics.
A Huygens principle for diffusion and anomalous diffusion in spatially extended systemsApr 12 2013May 09 2013We present a universal view on diffusive behaviour in chaotic spatially extended systems for anisotropic and isotropic media. For anisotropic systems, strong chaos leads to diffusive behaviour (Brownian motion with drift) and weak chaos leads to superdiffusive ... More
Computer Algebra Derivation of the Bias of Burg EstimatorsNov 04 2016A symbolic method is discussed which can be used to obtain the asymptotic bias and variance to order $O(1/n)$ for estimators in stationary time series. Using this method the bias to $O(1/n)$ of the Burg estimator in AR(1) and AR(2) models is shown to ... More
Partial autocorrelation parameterization for subset autoregressionNov 04 2016A new version of the partial autocorrelation plot and a new family of subset autoregressive models are introduced. A comprehensive approach to model identification, estimation and diagnostic checking is developed for these models. These models are better ... More
Faster ARMA maximum likelihood estimationNov 03 2016A new likelihood based AR approximation is given for ARMA models. The usual algorithms for the computation of the likelihood of an ARMA model require $O(n)$ flops per function evaluation. Using our new approximation, an algorithm is developed which requires ... More
Central limit theorems and suppression of anomalous diffusion for systems with symmetryApr 03 2014Feb 23 2015We give general conditions for the central limit theorem and weak convergence to Brownian motion (the weak invariance principle / functional central limit theorem) to hold for observables of compact group extensions of nonuniformly expanding maps. In ... More
Data Compression for CMB ExperimentsFeb 13 1997We discuss data compression for CMB experiments. Although "radical compression" to C_l bands, via quadratic estimators or local bandpowers, potentially offers a great savings in computation time, they do a considerably worse job at recovering the full ... More
Towards an understanding of the Of?p star HD 191612: optical spectroscopyJul 04 2007We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe-O8fp). The Balmer and HeI lines show strongly variable emission which is highly reproducible on a well-determined 538-d period. Metal lines and HeII absorptions ... More
A Period and a Prediction for the Of?p Spectrum Alternator HD 191612Sep 08 2004Nov 12 2004The observational picture of the enigmatic O-type spectrum variable HD191612 has been sharpened substantially. A symmetrical, low-amplitude light curve with a period near 540 d has recently been reported from Hipparcos photometry. This period satisfies ... More
MOA-2012-BLG-505Lb: A super-Earth mass planet probably in the Galactic bulgeMar 31 2017May 19 2017We report the discovery of a super-Earth mass planet in the microlensing event MOA-2012-BLG-505. This event has the second shortest event timescale of $t_{\rm E}=10 \pm 1$ days where the observed data show evidence of planetary companion. Our 15 minute ... More
EKR sets for large $n$ and $r$Oct 28 2012Let $\A\subset\binom{[n]}{r}$ be a compressed, intersecting family and let $X\subset[n]$. Let $\A(X)={A\in\A:A\cap X\ne\emptyset}$ and $\S_{n,r}=\binom{[n]}{r}({1})$. Motivated by the Erd\H{o}s-Ko-Rado theorem, Borg asked for which $X\subset[2,n]$ do ... More
Modeling the near-UV band of GK stars, Paper III: Dependence on abundance patternApr 17 2013We extend the grid of NLTE models presented in Paper II to explore variations in abundance pattern in two ways: 1) The adoption of the Asplund et al. (2009) (GASS10) abundances, 2) For stars of metallicity, [M/H], of -0.5, the adoption of a non-solar ... More
Broadband optical switch based on an achromatic photonic gauge potential in dynamically modulated waveguidesDec 03 2018We demonstrate that a photonic gauge potential, which arises from the phase degree of freedom in dynamic refractive index modulation and hence is achormatic, can be used to achieve a broadband optical switch using the configuration of a photonic Aharonov-Bohm ... More
Direct, Loss-Tolerant Characterization of Nonclassical Photon StatisticsJun 20 2006We experimentally investigate a method of directly characterizing the photon number distribution of nonclassical light beams that is tolerant to losses and makes use only of standard binary detectors. This is achieved in a single measurement by calibrating ... More
Spatially-Offset AGN Candidates in the CLASS SurveyJan 10 2018Prompted by a recent claim by Barrows et al. that X-ray AGN are often found significantly offset from the centres of their host galaxies, we have looked for examples of compact radio sources which are offset from the optical centroids of nearby (z < 0.2) ... More
Very Large Telescope deep echelle spectroscopy of Galactic planetary nebulae NGC 6153, M 1-42 and Hf 2-2Jun 09 2016We present deep spectroscopy of three Galactic planetary nebulae (PNe) with large abundance discrepancy factors (ADFs): NGC6153, M1-42 and Hf2-2. The spectra were obtained with VLT/UVES and cover the whole optical range (3040-11,000 A) with a spectral ... More
Handling localisation in rely/guarantee concurrency: An algebraic approachJul 09 2019The rely/guarantee approach of Jones extends Hoare logic with rely and guarantee conditions in order to allow compositional reasoning about shared-variable concurrent programs. This paper focuses on localisation in the context of rely/guarantee concurrency ... More
Lunar Exploration: Opening a Window into the History and Evolution of the Inner Solar SystemAug 12 2014The lunar geological record contains a rich archive of the history of the inner Solar System, including information relevant to understanding the origin and evolution of the Earth-Moon system, the geological evolution of rocky planets, and our local cosmic ... More
Improved Pena-Rodriguez Portmanteau TestNov 04 2016Several problems with the diagnostic check suggested by Pena and Rodriguez [2002. A powerful portmanteau test of lack of fit for time series. J. Amer. Statist. Assoc. 97, 601-610.] are noted and an improved Monte-Carlo version of this test is suggested. ... More
High Resolution Spectroscopy and High Contrast Imaging with the ELT : looking for O$_2$ in Proxima bJan 30 2019We research the requirements of High Contrast Imaging when combined with the cross correlation (CC) of high resolution spectra with known spectroscopic templates for detecting and characterising exoplanets in reflected light. We simulate applying the ... More
New Maser Emission from Nonmetastable Ammonia in NGC 7538. IV. Coincident Masers in Adjacent States of Para-ammoniaJan 01 2014We present the first detection of para-ammonia masers in NGC 7538: multiple epochs of observation of the 14NH3 (J,K) = (10,8) and (9,8) lines. We detect both thermal absorption and nonthermal emission in the (10,8) and (9,8) transitions and the absence ... More
Encoding fairness in a synchronous concurrent program algebra: extended version with proofsMay 04 2018Concurrent program refinement algebra provides a suitable basis for supporting mechanised reasoning about shared-memory concurrent programs in a compositional manner, for example, it supports the rely/guarantee approach of Jones. The algebra makes use ... More
Device Considerations for Nanophotonic CMOS Global InterconnectsJul 30 2012Dec 13 2012We introduce an analytical framework to understand the path for scaling nanophotonic interconnects to meet the energy and footprint requirements of CMOS global interconnects. We derive the device requirements for sub 100 fJ/cm/bit interconnects including ... More
Conformally flat pencils of metrics, Frobenius structures and a modified Saito constructionFeb 07 2005Mar 02 2005The structure of a Frobenius manifold encodes the geometry associated with a flat pencil of metrics. However, as shown in the authors' earlier work, much of the structure comes from the compatibility properties of the pencil rather than from the flatness ... More
Power Computations for Intervention AnalysisNov 05 2016In many intervention analysis applications time series data may be expensive or otherwise difficult to collect. In this case the power function is helpful since it can be used to determine the probability that a proposed intervention analysis application ... More
A tunable multiresolution smoother for scattered data with application to particle filteringJun 16 2019A smoothing algorithm is presented that can reduce the small-scale content of data observed at scattered locations in a spatially extended domain. The smoother works by forming a Gaussian interpolant of the input data, and then convolving the interpolant ... More
Heavy-ion double charge exchange reactions: a tool towards 0v\b{eta}\b{eta} nuclear matrix elementsNov 12 2015The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double ... More
Einstein metrics on tangent bundles of spheresFeb 28 2002We give an elementary treatment of the existence of complete Kahler-Einstein metrics with nonpositive Einstein constant and underlying manifold diffeomorphic to the tangent bundle of the (n+1)-sphere.
Fixed and Market Pricing for Cloud ServicesJan 26 2012This paper considers two simple pricing schemes for selling cloud instances and studies the trade-off between them. We characterize the equilibrium for the hybrid system where arriving jobs can choose between fixed or the market based pricing. We provide ... More
The brown dwarf desert as a consequence of orbital migrationNov 30 2001We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming at the same ... More
Models for the Formation of Massive StarsDec 05 2007Dec 17 2007The formation of massive stars is currently an unsolved problems in astrophysics. Understanding the formation of massive stars is essential because they dominate the luminous, kinematic, and chemical output of stars. Furthermore, their feedback is likely ... More
Spectral function of a Luttinger liquid coupled to phonons and angle-resolved photoemission measurements in the cuprate superconductorsFeb 18 2004Jan 25 2005We compute the finite-temperature single-particle spectral function of a one-dimensional Luttinger liquid coupled to an optical phonon band. The calculation is performed exactly for the case in which electron-phonon coupling is purely forward scattering. ... More
Modular Frobenius manifolds and their invariant flowsJun 03 2010The space of Frobenius manifolds has a natural involutive symmetry on it: there exists a map $I$ which send a Frobenius manifold to another Frobenius manifold. Also, from a Frobenius manifold one may construct a so-called almost dual Frobenius manifold ... More
Reasoning about effects: from lists to cyber-physical agentsJan 24 2018Theories for reasoning about programs with effects initially focused on basic manipulation of lists and other mutable data. The next challenge was to consider higher-order programming, adding functions as first class objects to mutable data. Reasoning ... More
Symmetries of F-manifolds with eventual identities and special families of connectionsMar 10 2011Sep 24 2012We construct a duality for F-manifolds with eventual identities and special families of connections and we describe its interactions with several well-known constructions from the theory of Frobenius and F-manifolds.
Logarithmic deformations of the rational superpotential/Landau-Ginzburg construction of solutions of the WDVV equationsMay 30 2006The superpotential in the Landau-Ginzburg construction of solutions to the Witten-Dijkgraaf-Verlinde-Verlinde (or WDVV) equations is modified to include logarithmic terms. This results in deformations - quadratic in the deformation parameters - of the ... More
The Use of Extraterrestrial Resources to Facilitate Space Science and ExplorationMay 25 2016May 26 2016To-date, all human economic activity has depended on the resources of a single planet, and it has long been recognized that developments in space exploration could in principle open our closed planetary economy to external resources of energy and raw ... More
Fundamental limits to signal integrity in nonlinear parametric optical circulatorsNov 06 2017We characterize the response of a parametric nonlinear optical circulator to realistic signals that have finite bandwidths. Our results show that intermodulation distortion (IMD), rather than pump depletion or compression, limits the maximal operating ... More
Sparsity-Exploiting Moment-Based Relaxations of the Optimal Power Flow ProblemApr 20 2014Nov 17 2014Convex relaxations of non-convex optimal power flow (OPF) problems have recently attracted significant interest. While existing relaxations globally solve many OPF problems, there are practical problems for which existing relaxations fail to yield physically ... More
Orbital migration and the brown dwarf desertOct 08 2002The orbital elements of extreme mass ratio binaries will be modified by interactions with surrounding circumstellar disks. For brown dwarf companions to Solar-type stars the resulting orbital migration is sufficient to drive short period systems to merger, ... More
On the cluster admission problem for cloud computingApr 20 2018Jun 21 2019Cloud computing providers must handle heterogeneous customer workloads for resources such as (virtual) CPU or GPU cores. This is particularly challenging if customers, who are already running a job on a cluster, scale their resource usage up and down ... More
Precision metrology using weak measurementsOct 20 2013May 31 2015Weak values and measurements have been proposed as means to achieve dramatic enhancements in metrology based on the greatly increased range of possible measurement outcomes. Unfortunately, the very large values of measurement outcomes occur with highly ... More
Broadband optical switch based on an achromatic photonic gauge potential in dynamically modulated waveguidesDec 03 2018Jun 29 2019We demonstrate that a photonic gauge potential, which arises from the phase degree of freedom in dynamic refractive-index modulation and hence is achormatic, can be used to achieve a broadband optical switch using the configuration of a photonic Aharonov-Bohm ... More
Benchmarking Physical Performance of Neural Inference CircuitsJul 12 2019Numerous neural network circuits and architectures are presently under active research for application to artificial intelligence and machine learning. Their physical performance metrics (area, time, energy) are estimated. Various types of neural networks ... More
Portmanteau Tests for ARMA Models with Infinite VarianceNov 04 2016Autoregressive and moving-average (ARMA) models with stable Paretian errors is one of the most studied models for time series with infinite variance. Estimation methods for these models have been studied by many researchers but the problem of diagnostic ... More
Frobenius manifolds and Frobenius algebra-valued integrable systemsFeb 28 2014Aug 31 2015The notion of integrability will often extend from systems with scalar-valued fields to systems with algebra-valued fields. In such extensions the properties of, and structures on, the algebra play a central role in ensuring integrability is preserved. ... More
On groups acting on contractible spaces with stabilizers of prime power orderMar 06 2009Aug 25 2009We study actions of discrete groups on contractible topological spaces in which either (1) all stabilizers lie in the family of subgroups of prime power order or (2) all stabilizers lie in the family of finite subgroups. We compare the classifying spaces ... More
Duality for Jacobi group orbit spaces and elliptic solutions of the WDVV equationsNov 13 2005From any given Frobenius manifold one may construct a so-called dual structure which, while not satisfying the full axioms of a Frobenius manifold, shares many of its essential features, such as the existence of a prepotential satisfying the WDVV equations ... More
Overview of Beyond-CMOS Devices and A Uniform Methodology for Their BenchmarkingFeb 01 2013Multiple logic devices are presently under study within the Nanoelectronic Research Initiative (NRI) to carry the development of integrated circuits beyond the CMOS roadmap. Structure and operational principles of these devices are described. Theories ... More
Nucleon form factors and spin content in a quark-diquark model with a pion cloudApr 19 2012Apr 23 2012We propose a new model of the nucleon in which quark-diquark configurations immersed in a pion cloud are treated in a manner consistent with Poincar\'e invariance. With suitably chosen parameters, the computations employing this model reproduce the measured ... More
Third Zemach Moment of the ProtonAug 25 2010Sep 09 2010Modern electron scattering experiments have determined the proton electric form factor, G_{Ep}(Q^2), to high precision. We utilize this data, represented by the different form factor parametrizations, to compute the third Zemach moment of the proton charge ... More
Compatible metrics on a manifold and non-local bi-Hamiltonian structuresApr 22 2004Given a flat metric one may generate a local Hamiltonian structure via the fundamental result of Dubrovin and Novikov. More generally, a flat pencil of metrics will generate a local bi-Hamiltonian structure, and with additional quasi-homogeneity conditions ... More