Results for "Oliver L. White"

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Grand Unification, Gravitational Waves, and the Cosmic Microwave Background AnisotropyMay 08 1992We re-examine the gravitational wave background resulting from inflation and its effect on the cosmic microwave background radiation. The new COBE measurement of a cosmic background quadrupole anisotropy places an upper limit on the vacuum energy during ... More
Oscillatory Modes of a Prominence-PCTR-Corona Slab ModelOct 16 2007Oscillations of magnetic structures in the solar corona have often been interpreted in terms of magnetohydrodynamic waves. We study the adiabatic magnetoacoustic modes of a prominence plasma slab with a uniform longitudinal magnetic field, surrounded ... More
Leptogenesis within a generalized quark-lepton symmetryAug 15 2007Oct 26 2007Quark-lepton symmetry has been shown to be inconsistent with baryogenesis via leptogenesis in natural schemes of the see-saw mechanism. Within the phenomenological approach of textures, we relax this strict symmetry and propose weaker conditions, namely ... More
The impact of charge symmetry and charge independence breaking on the properties of neutrons and protons in isospin-asymmetric nuclear matterMay 26 2012We investigate the effects of charge independence and charge symmetry breaking in neutron-rich matter. We consider neutron and proton properties in isospin-asymmetric matter at normal densities as well as the high-density neutron matter equation of state ... More
Mock Catalogs for the DEEP2 redshift surveyNov 10 2003Feb 12 2004We present a set of mock redshift catalogs, constructed from N-body simulations, designed to mimic the DEEP2 survey. Galaxies with a range of luminosities are placed within virialized halos in the simulation using a variant of the halo model. The halo ... More
Normal-mode-based analysis of electron plasma waves with second-order Hermitian formalismDec 27 2017The classic problem of the dynamic evolution of Langmuir electron waves in a collisionless plasma and their Landau damping is cast as a second-order, self-adjoint problem with a continuum spectrum of real and positive squared frequencies. The corresponding ... More
$R$-Parity Violation and Flavour ViolationSep 10 1996The MSSM with $R$-Parity violation allows flavour changing neutral currents through two mechanisms, directly through one loop diagrams, and indirectly through the generation of flavour violation in the sparticle sector. We discuss the use of these mechanisms ... More
Interactive Ant Colony Optimisation (iACO) for Early Lifecycle Software DesignDec 21 2012Jun 23 2014Software design is crucial to successful software development, yet is a demanding multi-objective problem for software engineers. In an attempt to assist the software designer, interactive (i.e. human in-the-loop) meta-heuristic search techniques such ... More
A Tiled-Table Convention for Compressing FITS Binary TablesJan 06 2012This document describes a convention for compressing FITS binary tables that is modeled after the FITS tiled-image compression method (White et al. 2009) that has been in use for about a decade. The input table is first optionally subdivided into tiles, ... More
Problems in a weakless universeSep 05 2006The fact that life has evolved in our universe constrains the laws of physics. The anthropic principle proposes that these constraints are sometimes very tight and can be used to explain in a sense the corresponding laws. Recently a "disproof" of the ... More
Solar Neutrino Data and Its ImplicationsMar 17 1992The complete and concurrent Homestake and Kamiokande solar neutrino data sets (including backgrounds), when compared to detailed model predictions, provide no unambiguous indication of the solution to the solar neutrino problem. All neutrino-based solutions, ... More
The PSCz catalogueSep 10 1999We present the catalogue and redshift data for the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. The uniformity, completeness and data quality are assessed, and guidelines and caveats for its use are given.
The dynamics of spontaneous hydrogen segregation in LaFe$_{13-x}$Si$_x$H$_y$Mar 07 2014May 07 2014By means of time- and temperature-dependent magnetization measurements, we demonstrate that the timescale of hydrogen diffusion in partially-hydrogenated LaFe$_{13-x}$Si$_x$H$_y$ is of the order of hours, when the material is held at temperatures close ... More
Optimal DN encoding for CCD detectorsOct 20 2009Image compression has been a frequent topic of presentations at ADASS. Compression is often viewed as just a technique to fit more data into a smaller space. Rather, the packing of data - its "density" - affects every facet of local data handling, long ... More
Multiplicity at the Stellar/Substellar Boundary in Upper ScorpiusJul 20 2005We present the results of a high-resolution imaging survey of 12 brown dwarfs and very low mass stars in the closest (~145 pc) young (~5 Myr) OB association, Upper Scorpius. We obtained images with the Advanced Camera for Surveys/High Resolution Camera ... More
Isochores Merit the Prefix 'Iso'Sep 20 2002The isochore concept in human genome sequence was challenged in an analysis by the International Human Genome Sequencing Consortium (IHGSC). We argue here that a statement in IGHSC analysis concerning the existence of isochore is incorrect, because it ... More
The Properties of Long-Period Variables in the Large Magellanic Cloud from MACHOAug 12 2008We present a new analysis of the long-period variables in the Large Magellanic Cloud (LMC) from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample ... More
On the support of neutrals against gravity in solar prominencesMar 18 2015Cool and dense prominences found in the solar atmosphere are known to be partially ionized because of their relative low temperature. In this Letter, we address the long-standing problem of how the neutral component of the plasma in prominences is supported ... More
Damping of filament thread oscillations: effect of the slow continuumFeb 03 2009Mar 19 2009Transverse oscillations of small amplitude are commonly seen in high-resolution observations of filament threads, i.e. the fine-structures of solar filaments/prominences, and are typically damped in a few periods. Kink wave modes supported by the thread ... More
Global shallow water magnetohydrodynamic waves in the solar tachoclineOct 23 2008Dec 05 2008We derive analytical solutions and dispersion relations of global magnetic Poincar\'e (magneto-gravity) and magnetic Rossby waves in the approximation of shallow water magnetohydrodynamics. The solutions are obtained in a rotating spherical coordinate ... More
Resonantly damped surface and body MHD waves in a solar coronal slab with oblique propagationAug 28 2007The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-$\beta$ configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is considered both surface ... More
Magnetic Rossby waves in the solar tachocline and Rieger-type periodicitiesNov 24 2009Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive ... More
Sum rules in the heavy quark limit of QCD and Isgur-Wise functionsDec 10 2004Using the OPE, we formulate new sum rules in the heavy quark limit of QCD. These sum rules imply that the elastic Isgur-Wise function $\xi (w)$ is an alternate series in powers of $(w-1)$. Moreover, one gets that the $n$-th derivative of $\xi (w)$ at ... More
Bounds on the derivatives of the Isgur-Wise function from sum rules in the heavy quark limit of QCDOct 16 2002Nov 06 2002Using the OPE and the trace formalism, we have obtained a number of sum rules in the heavy quark limit of QCD that include the sum over all excited states for any value $j^P$ of the light cloud. We show that these sum rules imply that the elastic Isgur-Wise ... More
Towards Schwinger production of magnetic monopoles in heavy-ion collisionsFeb 12 2019Magnetic monopoles may be produced by the Schwinger effect in the strong magnetic fields of peripheral heavy-ion collisions. We review the form of the electromagnetic fields in such collisions and calculate from first principles the cross section for ... More
A Correlation Between Circumstellar Disks and Rotation in the Upper Scorpius OB AssociationOct 03 2011We present projected rotational velocities for 20 early-type (B8-A9) and 74 late-type (F2-M8) members of the ~5 Myr old Upper Scorpius OB Association derived from high dispersion optical spectra obtained with the High Resolution Echelle Spectrometer (HIRES) ... More
Lossless Astronomical Image Compression and the Effects of NoiseMar 12 2009We compare a variety of lossless image compression methods on a large sample of astronomical images and show how the compression ratios and speeds of the algorithms are affected by the amount of noise in the images. In the ideal case where the image pixel ... More
The Last of FIRST: The Final Catalog and Source IdentificationsJan 06 2015Jan 09 2015The FIRST survey, begun over twenty years ago, provides the definitive high-resolution map of the radio sky. This VLA survey reaches a 20cm detection sensitivity of 1 mJy over 10,575 deg**2 largely coincident with the SDSS area. Images and a catalog containing ... More
Real-Root Preserving Differential Operator Representations of Orthogonal PolynomialsJul 17 2017In this paper, we study linear transformations of the form $T[x^n]=P_n(x)$ where $\{P_n(x)\}$ is an orthogonal polynomial system. Of particular interest is understanding when these operators preserve real-rootedness in polynomials. It is known that when ... More
Mock galaxy catalogs using the quick particle mesh methodSep 21 2013Oct 23 2013Sophisticated analysis of modern large-scale structure surveys requires mock catalogs. Mock catalogs are used to optimize survey design, test reduction and analysis pipelines, make theoretical predictions for basic observables and propagate errors through ... More
Numerical Model for Conduction-Cooled Current Lead Heat LoadsSep 13 2012Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories ... More
New Catalogs of Compact Radio Sources in the Galactic PlaneJan 27 2005May 19 2005Archival data have been combined with recent observations of the Galactic plane using the Very Large Array to create new catalogs of compact centimetric radio sources. The 20 cm source catalog covers a longitude range of -20 deg < l < 120 deg; the latitude ... More
Time-Dependence of the Mass Accretion Rate in Cluster Cooling FlowsMay 11 2000We analyze two time-dependent cluster cooling flow models in spherical symmetry. The first assumes that the intracluster gas resides in a static external potential, and includes the effects of optically thin radiative cooling and mass deposition. This ... More
Data-Driven Control of Distributed Reconfigurable Production-Inventory SystemsFeb 23 2019We analyze the value of mobile production capacity and transshipment in a supply chain with geographically distributed production facilities and epoch-dependent demands. We describe the L location, Y mobile production unit problem as a problem of sequential ... More
A Study of Optical Observing Techniques for Extra-Galactic Supernova Remnants: Case of NGC 300Feb 20 2012We present the results of a study of observational and identification techniques used for surveys and spectroscopy of candidate supernova remnants (SNRs) in the Sculptor Group galaxy NGC 300. The goal of this study was to investigate the reliability of ... More
Partially Observed, Multi-objective Markov GamesApr 16 2014The intent of this research is to generate a set of non-dominated policies from which one of two agents (the leader) can select a most preferred policy to control a dynamic system that is also affected by the control decisions of the other agent (the ... More
Analyzing data from DASIDec 20 1999We present an optimized layout of horn positions for the Degree Angular Scale Interferometer (DASI), which provides good coverage of the u-v plane and 3-fold symmetry. We investigate how an optimal subspace filtering analysis of a single pointing of DASI ... More
X-ray Binaries and Globular Clusters in Elliptical GalaxiesApr 10 2002The X-ray emission from normal elliptical galaxies has two major components: soft emission from diffuse gas and harder emission from populations of accreting (low-mass) stellar X-ray binaries (LMXB). If LMXB populations are tied to the field stellar populations ... More
A Radio Counterpart for the Unidentified TeV Source HESS J1813-178: The Radio-Gamma-Ray ConnectionMay 18 2005We discovered independently the shell-type supernova remnant G12.82-0.02, recently reported by Brogan et al. (2005), which is coincident with the unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic plane. Estimating the ambient ... More
Optimal Compression of Floating-point Astronomical Images Without Significant Loss of InformationJul 07 2010We describe a compression method for floating-point astronomical images that gives compression ratios of 6 -- 10 while still preserving the scientifically important information in the image. The pixel values are first preprocessed by quantizing them into ... More
High-Dispersion Optical Spectra of Nearby Stars Younger Than The SunJun 04 2007We present high-dispersion (R~16,000) optical (3900-8700 A) spectra of 390 stars obtained with the Palomar 60 inch telescope. The majority of stars observed are part of the Spitzer Legacy Science Program "The Formation and Evolution of Planetary Systems." ... More
Radio-Selected Quasars in the Sloan Digital Sky SurveySep 22 2009We have conducted a pilot survey for z>3.5 quasars by combining the FIRST radio survey with the SDSS. While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves the discovery ... More
Binding of holons and spinons in the one-dimensional anisotropic t-J modelFeb 08 2007Jun 29 2007We study the binding of a holon and a spinon in the one-dimensional anisotropic t-J model using a Bethe-Salpeter equation approach, exact diagonalization, and density matrix renormalization group methods on chains of up to 128 sites. We find that holon-spinon ... More
Extracting quantum dynamics from genetic learning algorithms through principal control analysisJan 06 2004Jul 15 2004Genetic learning algorithms are widely used to control ultrafast optical pulse shapes for photo-induced quantum control of atoms and molecules. An unresolved issue is how to use the solutions found by these algorithms to learn about the system's quantum ... More
Double Lobed Radio Quasars from the Sloan Digital Sky SurveyOct 26 2005We have combined a sample of 44984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio environment within 450", ... More
Seeing Galaxies Through Thick and Thin: II. Direct Measures of Extinction in Spiral Disks Through Spectroscopy of Overlapping GalaxiesJul 24 2000We use slit spectroscopy of overlapping pairs of galaxies to directly determine the extinction in disks of foreground spiral galaxies. The Doppler shifts of pair members are determined via cross-correlation and their relative correlation amplitudes are ... More
Interferometric Observation of Cosmic Microwave Background AnisotropiesDec 15 1997Aug 31 1998We present a formalism for analyzing interferometric observations of Cosmic Microwave Background (CMB) anisotropy and polarization data. The formalism is based upon the ell-space expansion of the angular power spectrum favoured in recent years. Explicit ... More
The VISTA Deep Extragalactic Observations (VIDEO) SurveyJun 19 2012Oct 03 2012In this paper we describe the first data release of the the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey. VIDEO is a ~12degree^2 survey in the near-infrared Z,Y,J,H and K_s bands, specifically ... More
Searching for signs of triggered star formation toward IC 1848Nov 03 2003We have carried out an in-depth study of three bright-rimmed clouds SFO 11, SFO 11NE and SFO 11E associated with the HII region IC 1848, using observations carried out at the James Clerk Maxwell Telescope (JCMT) and the Nordic Optical Telescope (NOT), ... More
Discovery of a High-Redshift (z=0.96) Cluster of Galaxies Using a FIRST Wide-Angle Tailed Radio SourceDec 18 2002Using a combination of near-infrared and optical photometry, along with multi-object spectroscopy, we have confirmed the existence of a high-redshift cluster of galxies at z = 0.96. The cluster was found using a wide-angle tailed radio source selected ... More
A Greedy Approach to Adapting the Trace Parameter for Temporal Difference LearningJul 02 2016One of the main obstacles to broad application of reinforcement learning methods is the parameter sensitivity of our core learning algorithms. In many large-scale applications, online computation and function approximation represent key strategies in ... More
Uncovering High-z Clusters Using Wide-Angle Tailed Radio SourcesMar 25 2003The morphologies of wide-angle tailed (WAT) radio sources (edge-darkened, C-shaped, FR I radio sources) are the result of confinement and distortion of the radio lobes by the dense X-ray-emitting gas in clusters or groups of galaxies. These radio sources ... More
Observations of T Tauri Disks at Sub-AU Radii: Implications for Magnetospheric Accretion and Planet FormationJan 14 2005We determine inner disk sizes and temperatures for four solar-type (1-2 M$_{\odot}$) classical T Tauri stars (AS 207A, V2508 Oph, AS 205A, and PX Vul) using 2.2 $\mu$m observations from the Keck Interferometer. Nearly contemporaneous near-IR adaptive ... More
The Gravitational Lens Candidate FBQ 1633+3134Nov 13 2000Dec 14 2000We present our ground-based optical imaging, spectral analysis, and high resolution radio mapping of the gravitational lens candidate FBQ 1633+3134. This z=1.52, B=17.7 quasar appears double on CCD images with an image separation of 0.66 arcseconds and ... More
Great Expectations: Plans and Predictions for New Horizons Encounter with Kuiper Belt Object 2014 MU69 ('Ultima Thule')Aug 06 2018The New Horizons encounter with the cold classical Kuiper Belt object (KBO) 2014 MU69 (informally named 'Ultima Thule,' hereafter Ultima) on 1 January 2019 will be the first time a spacecraft has ever closely observed one of the free-orbiting small denizens ... More
A Greedy Approach to Adapting the Trace Parameter for Temporal Difference LearningJul 02 2016Oct 24 2016One of the main obstacles to broad application of reinforcement learning methods is the parameter sensitivity of our core learning algorithms. In many large-scale applications, online computation and function approximation represent key strategies in ... More
Polishing of {100} and {111} single crystal diamond through the use of Chemical Mechanical PolishingFeb 14 2014Diamond is one of the hardest and most difficult to polish materials. In this paper, the polishing of {111} and {100} single crystal diamond surfaces by standard Chemical Mechanical Polishing, as used in the silicon industry, is demonstrated. A Logitech ... More
On Han's Hook Length Formulas for TreesMar 21 2011Recently, Han obtained two hook length formulas for binary trees and asked for combinatorial proofs. One of Han's formulas has been generalized to k-ary trees by Yang. Sagan has found a probabilistic proof of Yang's extension. We give combinatorial proofs ... More
Investigating practical linear temporal difference learningFeb 28 2016Mar 31 2016Off-policy reinforcement learning has many applications including: learning from demonstration, learning multiple goal seeking policies in parallel, and representing predictive knowledge. Recently there has been an proliferation of new policy-evaluation ... More
Possible explanation of the discrepancy of the light-cone QCD sum rule calculation of g(D*Dpi) coupling with experimentDec 12 2002The introduction of an explicit negative radial excitation contribution in the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun, Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi), recently measured by CLEO. ... More
Determination of the CP Violating Phase $γ$ by a Sum Over Common Decay Modes to $B_s$ and $\bar{B}_s$Jul 31 1994To help the difficult determination of the angle $\gamma$ of the unitarity triangle, Aleksan, Dunietz and Kayser have proposed the modes of the type $K^-D^+_s$, common to $B_s$ and $\bar{B}_s$. We point out that it is possible to gain in statistics by ... More
B To Light Meson Form FactorsJun 17 1994The heavy to light form factors in $B$ decays are discussed. Critical discussion of theoretical approaches is made with special emphasis on their failure to describe the $B \to K^{(\ast )}\psi$ data.
Resonant absorption in complicated plasma configurations: applications to multi-stranded coronal loop oscillationsFeb 05 2008We study the excitation and damping of transverse oscillations in a multi-stranded model of a straight line-tied coronal loop. The transverse geometry of our equilibrium configuration is quite irregular and more realistic than the usual cylindrical loop ... More
Decay constants in the heavy quark limit in models à la Bakamjian and ThomasOct 09 1997In quark models \`a la Bakamjian and Thomas, that yield covariance and Isgur-Wise scaling of form factors in the heavy quark limit, we compute the decay constants $f^{(n)}$ and $f^{(n)}_{1/2}$ of S-wave and P-wave mesons composed of heavy and light quarks. ... More
Semileptonic inclusive heavy meson decay: duality in a nonrelativistic potential model in the Shifman-Voloshin limitApr 27 2000Jun 07 2000Quark-hadron duality in the inclusive semileptonic decay $B\to X_c l\nu$ in the Shifman-Voloshin limit $\Lambda \ll \delta m=m_b - m_c \ll m_b, m_c$ is studied within a nonrelativistic potential model. The integrated semileptonic decay rate is calculated ... More
Experimental demonstration of continuous variable quantum erasingSep 01 2004We experimentally demonstrate the concept of continuous variable quantum erasing. The amplitude quadrature of the signal state is labelled to another state via a quantum nondemolition interaction, leading to a large uncertainty in the determination of ... More
Chemical mechanical polishing of thin film diamondAug 06 2013The demonstration that Nanocrystalline Diamond (NCD) can retain the superior Young's modulus (1,100 GPa) of single crystal diamond twinned with its ability to be grown at low temperatures (<450 {\deg}C) has driven a revival into the growth and applications ... More
Hook Length Formulas for Trees by Han's ExpansionMar 19 2009Recently Han obtained a general formula for the weight function corresponding to the expansion of a generating function in terms of hook lengths of binary trees. In this paper, we present formulas for k-ary trees, plane trees, plane forests, labeled trees ... More
Long Period Variables in the LMC: Results from MACHO and 2MASSOct 15 2004We use the eight year light-curve database from the MACHO (MAssive Compact Halo Objects) project together with infrared colors and magnitudes from 2MASS (the Two Micron All Sky Survey) to identify a sample of 22,000 long period variables in the Large ... More
q-Hook Length Formulas for Signed Labeled ForestsApr 11 2010Apr 13 2010A signed labeled forest is defined as a (plane) forest labeled by {1,2,..., n} along with minus signs associated to some vertices. Signed labeled forests can be viewed as an extension of signed permutations. We define the inversion number, the flag major ... More
Renormalization Group approach to Gravity: the running of G and L inside galaxies and additional details on the elliptical NGC 4494Jan 17 2013Jan 18 2013We explore the phenomenology of nontrivial quantum effects on low-energy gravity. These effects come from the running of the gravitational coupling parameter G and the cosmological constant L in the Einstein-Hilbert action, as induced by the Renormalization ... More
Quantifying the impact of tissue metabolism on solute transport in feto-placental microvascular networksFeb 22 2019The primary exchange units in the human placenta are terminal villi, in which fetal capillary networks are surrounded by a thin layer of villous tissue, separating fetal from maternal blood. To understand how the complex spatial structure of villi influences ... More
The origin of negative charging in amorphous Al$_2$O$_3$ films: The role of native defectsNov 01 2018Mar 04 2019Amorphous aluminum oxide Al$_2$O$_3$ (a-Al$_2$O$_3$) layers grown by various deposition techniques contain a significant density of negative charges. In spite of several experimental and theoretical studies, the origin of these charges still remains unclear. ... More
Calculating temperature-dependent properties of Nd$_2$Fe$_{14}$B permanent magnets by atomistic spin model simulationsFeb 14 2019Temperature-dependent magnetic properties of Nd$_2$Fe$_{14}$B permanent magnets, i.e., saturation magnetization $M_\text{s}(T)$, effective magnetic anisotropy constants $K_i^\text{eff}(T)$ ($i=1,2,3$), domain wall width $\delta_w(T)$, and exchange stiffness ... More
Deep Surveys and CosmologyJan 20 1999Surveys with ISO (Kessler et al 1996), in particular with the CAM (Cesarsky et al 1996) and PHOT (Lemke et al 1996) instruments, will greatly extend our understanding of extra-galactic populations and their cosmological evolution. The main advantages ... More
Correlation between measured and unmeasured quantities in quantum mechanics, locality, and the legitimacy of counterfactual reasoningApr 18 2010A correlation measure relating to measured and unmeasured local quantities in quantum mechanics is introduced, and is then applied to assess the locality implications for Bell/CHSH and similar set-ups. This leads to some interesting results, and the scheme ... More
Reply to Comment on "Counterfactual Entanglement and Nonlocal Correlations in Separable States"Aug 17 2000Two objections have been raised to the arguments presented in O. Cohen, Phys. Rev. A 60, 80 (1999). It is pointed out that neither objection has anything whatsoever to do with the main subject matter of that paper, and shown that both objections are based ... More
Deformation Spaces for Affine Crystallographic GroupsSep 04 2008We develop the foundations of the deformation theory of compact complete affine space forms and affine crystallographic groups. Using methods from the theory of linear algebraic groups we show that these deformation spaces inherit an algebraic structure ... More
A Septic with 99 real NodesSep 20 2004We find a surface of degree 7 in real projective three-space P^3(R) with 99 real nodes within a family of surfaces with dihedral symmetry: First, we consider this family over some small prime fields, which allows us to test all possible parameter sets ... More
Low analytic rank implies low partition rank for tensorsSep 28 2018A tensor defined over a finite field $\mathbb{F}$ has low analytic rank if the distribution of its values differs significantly from the uniform distribution. An order $d$ tensor has partition rank 1 if it can be written as a product of two tensors of ... More
Eulerian edge refinements, geodesics, billiards and sphere coloringAug 22 2018A finite simple graph is called a 2-graph if all of its unit spheres S(x) are cyclic graphs of length 4 or larger. A 2-graph G is Eulerian if all vertex degrees of G are even. An edge refinement of a graph splits an edge (a,b) to two edges (a,c),(c,b) ... More
On the relative K-group in the ETNCJun 28 2018We consider the Burns-Flach formulation of the equivariant Tamagawa number conjecture (ETNC). In their setup, a Tamagawa number is an element of a relative K-group. We show that this relative group agrees with an ordinary K-group, namely of the category ... More
Correlation asymptotics for non-translation invariant lattice spin systemsSep 22 2006Feb 19 2008We obtain asymptotic expressions for the Green kernels of certain non-translation invariant transition matrices using methods of semiclassical and microlocal analysis. Combined with a result by Bach and M{\o}ller this yields asymptotic formulas for the ... More
Constraint satisfaction problems in clausal formMar 18 2011This is the report-version of a mini-series of two articles on the foundations of satisfiability of conjunctive normal forms with non-boolean variables, to appear in Fundamenta Informaticae, 2011. These two parts are here bundled in one report, each part ... More
The congruence relation in the non-PEL caseMar 16 2014This work settles the Eichler-Shimura congruence relation of Blasius and Rogawski for certain 5-dimensional Hodge-type Shimura varieties, that were not tractable by previously known methods. In a more general context we introduce a hypothesis called (NVC) ... More
The Moduli Space of Stables Maps with Divisible RamificationDec 17 2018We develop a theory for stable maps to curves with divisible ramification. For a fixed integer $r>0$, we show that the condition of every ramification locus being divisible by $r$ is equivalent to the existence of an $r$th root of a canonical section. ... More
Reductive pairs arising from representationsDec 30 2014Let G be a reductive algebraic group and V a G-module. We consider the question of when (GL(V), rho(G)) is a reductive pair of algebraic groups, where rho is the representation afforded by V. We first make some observations about general G and V, then ... More
Higher algebraic structures in Hamiltonian Floer theory IIDec 08 2014Aug 05 2016This is the second of two papers devoted to showing how the rich algebraic formalism of Eliashberg-Givental-Hofer's symplectic field theory (SFT) can be used to define higher algebraic structures on symplectic cohomology. Using the SFT of Hamiltonian ... More
Functional equations for zeta functions of $\mathbb{F}_1$-schemesOct 08 2010For a scheme $X$ whose $\mathbb F_q$-rational points are counted by a polynomial $N(q)=\sum a_iq^i$, the $\mathbb{F}_1$-zeta function is defined as $\zeta(s)=\prod(s-i)^{-a_i}$. Define $\chi=N(1)$. In this paper we show that if $X$ is a smooth projective ... More
The equivariant cohomology of isotropy actions on symmetric spacesSep 21 2010Oct 19 2010We show that for every symmetric space G/K of compact type with K connected, the K-action on G/K by left translations is equivariantly formal.
The hydrogen identity for LaplaciansMar 05 2018For any finite simple graph G, the hydrogen identity H=L-L^(-1) holds, where H=(d+d^*)^2 is the sign-less Hodge Laplacian defined by sign-less incidence matrix d and where L is the connection Laplacian. Any spectral information about L directly leads ... More
Gravitational descendants in symplectic field theoryJul 04 2009Mar 25 2010It was pointed out by Y. Eliashberg in his ICM 2006 plenary talk that the rich algebraic formalism of symplectic field theory leads to a natural appearance of quantum and classical integrable systems, at least in the case when the contact manifold is ... More
Theoretical properties of Cook's PFC dimension reduction algorithm for linear regressionJun 25 2008Sep 18 2008We analyse the properties of the Principal Fitted Components (PFC) algorithm proposed by Cook. We derive theoretical properties of the resulting estimators, including sufficient conditions under which they are $\sqrt{n}$-consistent, and explain some of ... More
Information inequalities and a dependent Central Limit TheoremOct 03 2008We adapt arguments concerning information-theoretic convergence in the Central Limit Theorem to the case of dependent random variables under Rosenblatt mixing conditions. The key is to work with random variables perturbed by the addition of a normal random ... More
A Central Limit Theorem for non-overlapping return timesJun 09 2005Define the non-overlapping return time of a random process to be the number of blocks that we wait before a particular block reappears. We prove a Central Limit Theorem based on these return times. This result has applications to entropy estimation, and ... More
On quadratic orbital networksDec 02 2013These are some informal remarks on quadratic orbital networks over finite fields. We discuss connectivity, Euler characteristic, number of cliques, planarity, diameter and inductive dimension. We find a non-trivial disconnected graph for d=3. We prove ... More
The Kuenneth formula for graphsMay 28 2015We construct a Cartesian product G x H for finite simple graphs. It satisfies the Kuenneth formula: H^k(G x H) is a direct sum of tensor products H^i(G) x H^j(G) with i+j=k and so p(G x H,x) = p(G,x) p(H,y) for the Poincare polynomial p(G,x) and X(G x ... More
On the Dimension and Euler characteristic of random graphsDec 24 2011The inductive dimension dim(G) of a finite undirected graph G=(V,E) is a rational number defined inductively as 1 plus the arithmetic mean of the dimensions of the unit spheres dim(S(x)) at vertices x primed by the requirement that the empty graph has ... More
Isospectral deformations of the Dirac operatorJun 24 2013We give more details about an integrable system in which the Dirac operator D=d+d^* on a finite simple graph G or Riemannian manifold M is deformed using a Hamiltonian system D'=[B,h(D)] with B=d-d^* + i b. The deformed operator D(t) = d(t) + b(t) + d(t)^* ... More
An integrable evolution equation in geometryJun 01 2013We introduce an integrable Hamiltonian system which Lax deforms the Dirac operator D=d+d* on a finite simple graph or compact Riemannian manifold. We show that the nonlinear isospectral deformation always leads to an expansion of the original space, featuring ... More