Results for "Dennis Stello"

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Photometry Using Kepler "Superstamps" of Open Clusters NGC 6791 & NGC 6819Sep 24 2013The Kepler space telescope has proven to be a gold mine for the study of variable stars. Unfortunately, Kepler only returns a handful of pixels surrounding each star on the target list, which omits a large number of stars in the Kepler field. For the ... More
Gaussian Process Modelling of Asteroseismic DataFeb 23 2009The measured properties of stellar oscillations can provide powerful constraints on the internal structure and composition of stars. To begin this process, oscillation frequencies must be extracted from the observational data, typically time series of ... More
The problem of the Pleiades distance. Constraints from Stromgren photometry of nearby field starsMay 14 2001The discrepancy between the Pleiades cluster distance based on Hipparcos parallaxes and main sequence fitting is investigated on the basis of Stromgren photometry of F-type stars. Field stars with the same metallicity as the Pleiades have been selected ... More
The SAGA so far: reading the history of the Galaxy with asteroseismologyNov 13 2014Asteroseismology has the capability of delivering stellar properties which would otherwise be inaccessible, such as radii, masses and thus ages of stars. When this information is coupled with classical determinations of stellar parameters, such as metallicities, ... More
Asteroseismology of red giant starsJan 25 2018If appropriately excited, a star will oscillate like a giant spherical instrument. In most stars, including the Sun, surface convection provides the excitation mechanism (Goldreich and Keeley, 1977). With turbulent velocities reaching speeds comparable ... More
Deep Learning Classification in Asteroseismology Using an Improved Neural Network: Results on 15000 Kepler Red Giants and Applications to K2 and TESS DataFeb 20 2018Deep learning in the form of 1D convolutional neural networks have previously been shown to be capable of efficiently classifying the evolutionary state of oscillating red giants into red giant branch stars and helium-core burning stars by recognizing ... More
The Physical Parameters of the Retired A Star HD185351Jul 09 2014We report here an analysis of the physical stellar parameters of the giant star HD185351 using Kepler short-cadence photometry, optical and near infrared interferometry from CHARA, and high-resolution spectroscopy. Asteroseismic oscillations detected ... More
Detecting Solar-like Oscillations in Red Giants with Deep LearningApr 20 2018Time-resolved photometry of tens of thousands of red giant stars from space missions like Kepler and K2 has created the need for automated asteroseismic analysis methods. The first and most fundamental step in such analysis, is to identify which stars ... More
Bayesian Inference from Observations of Solar-Like OscillationsAug 26 2006Stellar oscillations can provide a wealth of information about a star, which can be extracted from observed time series of the star's brightness or radial velocity. In this paper we address the question of how to extract as much information as possible ... More
The K2 M67 Study: An Evolved Blue Straggler in M67 from K2 Mission AsteroseismologyNov 03 2016Yellow straggler stars (YSSs) fall above the subgiant branch in optical color-magnitude diagrams, between the blue stragglers and the red giants. YSSs may represent a population of evolved blue stragglers, but none have the direct and precise mass and ... More
Confirmation of the zero-point offset in Gaia Data Release 2 parallaxes using asteroseismology and APOGEE spectroscopy in the Kepler fieldMay 07 2018We present an independent confirmation of the zero-point offset of Gaia Data Release 2 (DR2) parallaxes using asteroseismic data of evolved stars in the Kepler field. Using well-characterized red giant branch (RGB) stars from the APOKASC-2 catalogue we ... More
Modeling Kepler Observations of Solar-like Oscillations in the Red-giant Star HD 186355Sep 05 2011Nov 28 2011We have analysed oscillations of the red giant star HD 186355 observed by the NASA Kepler satellite. The data consist of the first five quarters of science operations of Kepler, which cover about 13 months. The high-precision time-series data allow us ... More
Asteroseismology of main-sequence F stars with \textit{Kepler}: overcoming short mode lifetimesFeb 14 2019Asteroseismology is a powerful way of determining stellar parameters and properties of stars like the Sun. However, main-sequence F-type stars exhibit short mode lifetimes relative to their oscillation frequency, resulting in overlapping radial and quadrupole ... More
The Fractured Boer-Mulders Effect in the Production of Polarized BaryonsOct 28 2009The fractured Boer-Mulders functions describe an inriguing class of polarization effects for the production of baryons in the target fragmentation region of deep-inelastic processes. These functions characterize transverse momentum asymmetries related ... More
Single-Spin Observables and Orbital Structures in Hadronic DistributionsSep 07 2006Within the light-quark sector of the standard model, P-odd observables are generated from point-like electroweak processes while A_t- odd observables (neglecting quark mass parameters) come from dynamic spin-orbit correlations within hadrons or within ... More
Lazier ABCJan 21 2015ABC algorithms involve a large number of simulations from the model of interest, which can be very computationally costly. This paper summarises the lazy ABC algorithm of Prangle (2015), which reduces the computational demand by abandoning many unpromising ... More
Shape/Phase Transitions and Critical Point Symmetries in Atomic NucleiJul 28 2008Shape/phase transitions in atomic nuclei have first been discovered in the framework of the Interacting Boson Approximation (IBA) model. Critical point symmetries appropriate for nuclei at the transition points have been introduced as special solutions ... More
$C^{1,α}$ Interior Regularity for Nonlinear Nonlocal Elliptic Equations With Rough KernelsApr 28 2013We prove a $C^{1,\alpha}$ interior regularity theorem for fully nonlinear uniformly elliptic integro-differential equations without assuming any regularity of the kernel. We then give some applications to linear theory and higher regularity of a special ... More
Discriminants and Artin conductorsJun 15 2011We study questions of multiplicities of discriminants for degenerations coming from projective duality over discrete valuation rings. The main result is a type of discriminant-different formula in the sense of classical algebraic number theory, and we ... More
The Logic of Identity: Distinguishability and Indistinguishability in Classical and Quantum PhysicsMay 13 2014The suggestion that particles of the same kind may be indistinguishable in a fundamental sense, even so that challenges to traditional notions of individuality and identity may arise, has first come up in the context of classical statistical mechanics. ... More
Implications and Applications of Kinematic Galaxy Scaling RelationsSep 19 2012Galaxy scaling relations, which describe a connection between ostensibly unrelated physical characteristics of galaxies, testify to an underlying order in galaxy formation that requires understanding. I review the development of a scaling relation that ... More
The Atiyah-Bott formula for the cohomology of the moduli space of bundles on a curveMay 10 2015This paper is a companion of the paper "Weil's conjecture for function fields" by J. Lurie and the author. We present a different exposition of essentially the same algebro-geometric proof of the Atiyah-Bott for the cohomology of Bun(G), which subsequently ... More
Eisenstein series and quantum groupsMay 10 2015May 23 2016We sketch a proof of a conjecture of [FFKM] that relates the geometric Eisenstein series sheaf with semi-infinite cohomology of the small quantum group with coefficients in the tilting module for the big quantum group.
Twisted Whittaker model and factorizable sheavesMay 31 2007Mar 27 2008Let G be a reductive group. The geometric Satake equivalence realized the category of representations of the Langlands dual group ^LG in terms of spherical perverse sheaves (or D-modules) on the affine Grassmannian Gr_G=G((t))/G[[t]] of the original group ... More
Grothendieck topologies and deformation theory IIAug 08 1995This paper is a continuation of ``Operads, Grothendieck topologies and deformation theory'' (alg-geom/9502010). We show how to develop a cohomology theory that would control deformations of a sheaf of associative algebras over a scheme by means of introducing ... More
From geometric to function-theoretic Langlands (or how to invent shtukas)Jun 30 2016This is an informal note that explains that the classical Langlands theory over function fields can be obtained from the geometric one by taking the trace of Frobenius. The operation of taking the trace of Frobenius takes place at the categorical level, ... More
Quantum Langlands CorrespondenceJan 20 2016These are informal notes written in 2007 that outline the local and global quantum Langlands program. (I decided to make them public in view of the revived interest in the subject.)
A finite time blowup result for quadratic ODE'sNov 01 2010This short paper is dedicated to Mauricio Peixoto who abstracted the practical theory of ODE's and to David Rand who applied the subsequent powerful abstract theory to practical problems.
The AJ-conjecture and cabled knots over the figure eight knotMay 15 2014Apr 15 2015We show that most cabled knots over the figure eight knot in $S^3$ satisfy the AJ-conjecture, in particular, any $(r,s)$-cabled knot over the figure eight knot satisfies the $AJ$-conjecture if $r$ is not a number between $-4s$ and $4s$.
On the Chow Ring of the Stack of truncated Barsotti-Tate GroupsNov 27 2016We determine the Chow ring of the stack of truncated displays and more generally the Chow ring of the stack of G-zips. We also investigate the pull-back morphism of the truncated display functor. From this we can determine the Chow ring of the stack of ... More
A Free Boundary Problem Related to Thermal Insulation: Flat Implies SmoothNov 18 2015We show that for a new free boundary problem studied by Caffarelli and the author, the interface is locally the union of the graphs of two $C^{1,\alpha}$ functions at most points. Specifically, this happens at all points where the interface is trapped ... More
Symmetric noncommutative birational transformationsJul 28 2016In a previous paper (arXiv:1410.5207) certain birational transformations were constructed between the noncommutative schemes associated to quadratic and cubic three dimensional Sklyanin algebras. In the current paper we consider the inverse birational ... More
Complete families of immersed curvesNov 01 2017Jan 31 2019We extend results of Chang and Ran regarding large dimensional families of immersed curves of positive genus in projective space in two directions. In one direction, we prove a sharp bound for the dimension of a complete family of smooth rational curves ... More
Measures on polyhedral cones: characterizations and kinematic formulasDec 04 2014Jul 29 2015This paper is about conic intrinsic volumes and their associated integral geometry. We pay special attention to the biconic localizations of the conic intrinsic volumes, the so-called support measures. An analysis of these quantities has so far been confined ... More
Dust and Stellar Populations in the Large Magellanic CloudAug 31 1999We present an analysis of line-of-sight extinction measurements obtained using data from the Magellanic Clouds Photometric Survey, which provides 4-filter photometry for millions of stars in the Large Magellanic Cloud. We find that visual extinctions ... More
The Mass and Extent of the Galactic HaloOct 05 1998We review the various techniques used to constrain the Galactic halo mass profile for radii > 20 kpc with particular emphasis on identifying a self-consistent halo model and resolving the apparent discrepancies present in the literature on this subject. ... More
Evidence For Recent Accretion in Nearby GalaxiesMay 11 1995I discuss observations of magnitude residuals from the B-band Tully-Fisher relationship, B-V color, chemical abundance gradients, and asymmetries in the H I and stellar disks of nearby spiral galaxies within the context of a model in which small satellites ... More
The Case of the Off-Center, Levitating Bar in the Large Magellanic CloudAug 28 2004I explore the hypothesis that many of the unusual aspects of the apparent stellar bar of the Large Magellanic Cloud are the result of viewing a triaxial stellar bulge that is embedded in a highly obscuring thin disk. Specifically, this hypothesis explains ... More
Topological characterization of various types of rings of smooth functionsAug 30 2011Oct 02 2011Topologies on algebraic and equational theories are used to define germ determined, near-point determined, and point determined rings of smooth functions, without requiring them to be finitely generated. It is proved, that any commutative algebra morphism ... More
Lazy ABCMay 30 2014Dec 04 2014Approximate Bayesian computation (ABC) performs statistical inference for otherwise intractable probability models by accepting parameter proposals when corresponding simulated datasets are sufficiently close to the observations. Producing the large quantity ... More
Is There a Unique Physical Entropy? Micro versus MacroSep 05 2012Entropy in thermodynamics is an extensive quantity, whereas standard methods in statistical mechanics give rise to a non-extensive expression for the entropy. This discrepancy is often seen as a sign that basic formulas of statistical mechanics should ... More
On the dynamic nature of charge quantizationDec 29 2011It is commonly observed that objects in a gravitational field experience a rate of acceleration that is independent of their mass and that, as a result, all massive objects with the same initial conditions follow the same trajectory. It is not generally ... More
Conformal geometry of surfaces in the Lagrangian--Grassmannian and second order PDESep 07 2010Of all real Lagrangian--Grassmannians $LG(n,2n)$, only $LG(2,4)$ admits a distinguished (Lorentzian) conformal structure and hence is identified with the indefinite M\"obius space $S^{1,2}$. Using Cartan's method of moving frames, we study hyperbolic ... More
Comment on "Harold Jeffreys's Theory of Probability Revisited"Jan 18 2010Comment on "Harold Jeffreys's Theory of Probability Revisited" [arXiv:0804.3173]
A Deligne-Riemann-Roch isomorphism I: Preliminaries on virtual categoriesApr 26 2009This is the first article in an upcoming series of papers. They have arisen through an attempt to answer open questions of Deligne proposed in "Le determinant de la cohomologie", Contemp. Mathematics 67 (1987). It amounts to functorial and metrized versions ... More
Outline of the proof of the geometric Langlands conjecture for GL(2)Feb 11 2013Nov 12 2014We outline a proof of the categorical geometric Langlands conjecture for GL(2), as formulated in reference [AG], modulo a number of more tractable statements that we call Quasi-Theorems.
On de Jong's conjectureFeb 11 2004Apr 01 2006Let $X$ be a smooth projective curve over a finite field $F_q$. Let $\rho$ be a continuous representation $\pi(X)\to GL_n(F)$, where $F=F_l((t))$ with $F_l$ being another finite field of order prime to $q$. Assume that $\rho|_{\pi(\bar{X})}$ is irreducible. ... More
Hilbert space compression under direct limits and certain group extensionsSep 10 2010Sep 14 2010We find bounds on the Hilbert space compression of the limit of a directed metric system of groups. We also give estimates on the Hilbert space compression of group extensions of a group $H$ by a a word-hyperbolic group or a group of polynomial growth. ... More
DBI analog of a decaying vacuum cosmologyJul 03 2013Jul 04 2013In this work I discuss the dynamical and thermodynamical equivalence between a general k-essence scalar field cosmology and an arbitrary cosmological model with a decaying vacuum, thus generalizing the approach proposed by Maia and Lima [Phys. Rev. D ... More
String Topology: Background and Present StateOct 22 2007The data of a "2D field theory with a closed string compactification" is an equivariant chain level action of a cell decomposition of the union of all moduli spaces of punctured Riemann surfaces with each component compactified as a pseudomanifold with ... More
On the Chow Ring of the Classifying Space of some Chevalley GroupsNov 23 2016Let $p$ be a prime and $q$ be a power of $p$. We compute the Chow ring of the classifying space of some Chevalley groups $G(\mathbb{F}_q)$, when considered as a finite algebraic group over a field of characteristic $p$ containing $\mathbb{F}_q$. Using ... More
Binomial Andrews-Gordon-Bressoud identitiesAug 03 2016Binomial versions of the Andrews-Gordon-Bressoud identities are given.
Binary star detectability in $Kepler$ data from phase modulation of different types of oscillationsMay 11 2016Detecting binary stars in photometric time series is traditionally done by measuring eclipses. This requires the orbital plane to be aligned with the observer. A new method without that requirement uses stellar oscillations to measure delays in the light ... More
Some Comments on the Stochastic Eulerian Tour ProblemMar 13 2015The Stochastic Eulerian Tour Problem was introduced in 2008 as a stochastic variant of the well-known Eulerian Tour Problem. In a follow-up paper the same authors investigated some heuristics for solving the Stochastic Eulerian Tour Problem. After a thorough ... More
Recent progress in geometric Langlands theoryJun 30 2016Sep 10 2016The is the English version of the text of the talk at S\'eminaire Bourbaki on February 16, 2016
Functors given by kernels, adjunctions and dualityMar 12 2013Nov 24 2015Let X_1 and X_2 be schemes of finite type over a field of characteristic 0. Let Q be an object in the category D-mod(X_1\times X_2) and consider the functor F:D-mod(X_1)->Dmod(X_2) defined by Q. Assume that F admits a right adjoint also defined by an ... More
The notion of category over an algebraic stackJul 09 2005The goal of this note is to spell out the (apparently well-known and intuitively clear) notion of abelian category over an algebraic stack. In the future we will discuss the (much less evident) notion, when instead of an abelian category one considers ... More
A Central Limit Theorem for Lipschitz-Killing Curvatures of Gaussian ExcursionsJul 22 2016This paper studies the excursion set of a real stationary isotropic Gaussian random field above a fixed level. We show that the standardized Lipschitz-Killing curvatures of the intersection of the excursion set with a window converges in distribution ... More
Quantum Number Density Asymmetries Within QCD Jets Correlated With Lambda PolarizationJun 20 2011Jul 27 2011The observation of jets in a variety of hard-scattering processes has allowed the quantitative study of perturbative quantum chromodynamics (PQCD) by comparing detailed theoretical predictions with a wide range of experimental data. This paper examines ... More
Coherent Spin Manipulations of a Polarized Beam With a Localized RF Magnetic FieldOct 12 2007The coherent manipulation of spin observables in storage rings provides opportunities to test the application of some fundamental dynamical principles. In this context, it is possible to confirm, using gauge invariance and Lorentz invariance, a conjecture ... More
Ideas in transverse spin physicsSep 08 2014Three simple ideas about transverse spin observables are presented for the purpose of stimulating discussion. The manuscript is based on a presentation at the "Transversity 2014" workshop in Torre Chia, Sardinia, Italy on June 9-13, 2014 where approximately ... More
Kane-Pumplin-Repko Factorization: its application to precision measurements of transverse spin asymmetries and to the study of TMD evolutionJul 22 2013This article presents a summary of overlapping presentations by the author to the QCD Evolution 2013 Workshop and to the Opportunities for Polarized Physics at Fermilab Workshop. It contains an introduction to the concept of Kane-Pumplin-Repko (KPR) factorization ... More
Perturbed and Permuted: Signal Integration in Network-Structured Dynamic SystemsJun 23 2011Biological systems (among others) may respond to a large variety of distinct external stimuli, or signals. These perturbations will generally be presented to the system not singly, but in various combinations, so that a proper understanding of the system ... More
Ind-coherent sheavesMay 24 2011Sep 22 2012We develop the theory of ind-coherent sheaves on schemes and stacks. The category of ind-coherent sheaves is closely related, but inequivalent, to the category of quasi-coherent sheaves, and the difference becomes crucial for the formulation of the categorical ... More
Invariant Yang-Mills connections over Non-Reductive Pseudo-Riemannian Homogeneous SpacesOct 09 2007Apr 17 2008We study invariant gauge fields over the 4-dimensional non-reductive pseudo-Riemannian homogeneous spaces G/K recently classified by Fels & Renner (2006). Given H compact semi-simple, classification results are obtained for principal H-bundles over G/K ... More
Regularity for a Local-Nonlocal Transmission ProblemApr 04 2014Jan 31 2015We formulate and study an elliptic transmission-like problem combining local and nonlocal elements. Let $\mathbb{R}^{n}$ be separated into two components by a smooth hypersurface $\Gamma$. On one side of $\Gamma$, a function satisfies a local second-order ... More
On two relaxations of quadratically-constrained cardinality minimizationOct 18 2012This paper considers a quadratically-constrained cardinality minimization problem with applications to digital filter design, subset selection for linear regression, and portfolio selection. Two relaxations are investigated: the continuous relaxation ... More
Exceptionally simple PDEMar 27 2016Sep 29 2016We give local descriptions of parabolic contact structures and show how their flat models yield explicit PDE having symmetry algebras isomorphic to all complex simple Lie algebras except $\mathfrak{sl}_2$. This yields a remarkably uniform generalization ... More
Solar-like oscillating stars as standard clocks and rulers for Galactic studiesSep 08 2014The CoRoT and Kepler space missions have detected oscillations in hundreds of Sun-like stars and thousands of field red-giant stars. This has opened the door to a new era of stellar population studies in the Milky Way. We report on the current status ... More
The treatment of mixing in core helium burning models - I. Implications for asteroseismologyJun 03 2015Jul 03 2015The detection of mixed oscillation modes offers a unique insight into the internal structure of core helium burning (CHeB) stars. The stellar structure during CHeB is very uncertain because the growth of the convective core, and/or the development of ... More
Calculating asteroseismic diagrams for solar-like oscillationsSep 15 2011With the success of the Kepler and CoRoT missions, the number of stars with detected solar-like oscillations has increased by several orders of magnitude, for the first time we are able to perform large-scale ensemble asteroseismology of these stars. ... More
Asteroseismology of 16000 Kepler red giants: Global oscillation parameters, Masses, and radiiFeb 13 2018The Kepler mission has provided exquisite data to perform an ensemble asteroseismic analysis on evolved stars. In this work we systematically characterize solar-like oscillations and granulation for 16,094 oscillating red giants, using end-of-mission ... More
Asteroseismology of 16000 Kepler Red Giants: Global Oscillation Parameters, Masses, and RadiiFeb 13 2018Apr 03 2018The Kepler mission has provided exquisite data to perform an ensemble asteroseismic analysis on evolved stars. In this work we systematically characterize solar-like oscillations and granulation for 16,094 oscillating red giants, using end-of-mission ... More
Summary Statistics in Approximate Bayesian ComputationDec 17 2015This document is due to appear as a chapter of the forthcoming Handbook of Approximate Bayesian Computation (ABC) edited by S. Sisson, Y. Fan, and M. Beaumont. Since the earliest work on ABC, it has been recognised that using summary statistics is essential ... More
The Gibbs Paradox RevisitedFeb 28 2010The Gibbs paradox has frequently been interpreted as a sign that particles of the same kind are fundamentally indistinguishable; and that quantum mechanics, with its identical fermions and bosons, is indispensable for making sense of this. In this article ... More
Probability in modal interpretations of quantum mechanicsMar 02 2007Modal interpretations have the ambition to construe quantum mechanics as an objective, man-independent description of physical reality. Their second leading idea is probabilism: quantum mechanics does not completely fix physical reality but yields probabilities. ... More
Clues to the nature of ultra diffuse galaxies from estimated galaxy velocity dispersionsSep 26 2016Oct 17 2016We describe how to estimate the velocity dispersions of ultra diffuse galaxies, UDGs, using a previously defined galaxy scaling relationship. The method is accurate for the two UDGs with spectroscopically measured dispersions, as well as for ultra compact ... More
The Adventure and the PrizeSep 12 2011This article presnts a condensed summary of separate, overlapping, presentations to the Workshop on Polarized Drell-Yan Physics (Santa Fe, NM, Oct. 31-Nov.1, 2010),the GHP 2011 Worshop (Anaheim, CA, Apr.21-27, 2011) and the Transversity 2011 Workshop ... More
Chiral Dynamics and Single-Spin AsymmetriesNov 20 2007Parity-conserving single-spin asymmetries provide a specific measure of coherent spin-orbit dynamics in quantum chromodynamics. The origin of these effects can be traced to the interplay of chiral dynamics and confinement in the theory. The most elegant ... More
Chiral Mechanisms Leading to Orbital Quantum Structures in the NucleonApr 13 2007Color confinement and chiral symmetry specify some important territory for the study of hadronic physics. Any hadron can be defined as a color-singlet composite system of qurks and gluons, the fundamental fields of qcd, while the landscape of the hadronic ... More
Extending Immersions into the SphereDec 22 2010We study the problem to extend an immersed circle f in the 2-dimensional sphere to an immersion of the disc. We analyze existence and uniqueness for this problems in terms of the combinatorial structure of a word assigned to f. Our techniques are based ... More
Contact Geometry of Hyperbolic Equations of Generic TypeApr 09 2008Aug 19 2008We study the contact geometry of scalar second order hyperbolic equations in the plane of generic type. Following a derivation of parametrized contact-invariants to distinguish Monge-Ampere (class 6-6), Goursat (class 6-7) and generic (class 7-7) hyperbolic ... More
Adaptive Sensing Resource Allocation Over Multiple Hypothesis TestsOct 03 2014Nov 03 2014This paper considers multiple binary hypothesis tests with adaptive allocation of sensing resources from a shared budget over a small number of stages. A Bayesian formulation is provided for the multistage allocation problem of minimizing the sum of Bayes ... More
Unions of arcs from Fourier partial sumsFeb 03 2010Mar 03 2010Elementary complex analysis and Hilbert space methods show that a union of at most n arcs on the circle is uniquely determined by the nth Fourier partial sum of its characteristic function. The endpoints of the arcs can be recovered from the coefficients ... More
A note on rational curves on general Fano hypersurfacesSep 27 2017Jan 31 2019We show the Kontsevich space of rational curves of degree at most roughly $\frac{2-\sqrt{2}}{2}n$ on a general hypersurface $X\subset \mathbb{P}^n$ of degree $n-1$ is equidimensional of expected dimension and has two components: one consisting generically ... More
Divisors on the moduli space of curves from divisorial conditions on hypersurfacesJan 31 2019In this note, we extend work of Farkas and Rim\'anyi on applying quadric rank loci to finding divisors of small slope on the moduli space of curves by instead considering all divisorial conditions on the hypersurfaces of a fixed degree containing a projective ... More
Bootstrapping the Kaplan-Meier Estimator on the Whole LineMay 18 2016This article is concerned with proving the consistency of Efron's (1981) bootstrap for the Kaplan-Meier estimator on the whole support of a survival function. While other works address the asymptotic Gaussianity of the estimator itself without restricting ... More
Stellar population synthesis based modelling of the Milky Way using asteroseismology of 13000 Kepler red giantsMar 17 2016With current space-based missions it is now possible to obtain age-sensitive asteroseismic information for tens of thousands of red giants. This provides a promising opportunity to study the Galactic structure and evolution. We use asteroseismic data ... More
A comparison of Bayesian and Fourier methods for frequency determination in asteroseismologyJun 21 2010Bayesian methods are becoming more widely used in asteroseismic analysis. In particular, they are being used to determine oscillation frequencies, which are also commonly found by Fourier analysis. It is important to establish whether the Bayesian methods ... More
Asteroseismology Can Reveal Strong Internal Magnetic Fields in Red Giant StarsOct 23 2015Internal stellar magnetic fields are inaccessible to direct observations and little is known about their amplitude, geometry and evolution. We demonstrate that strong magnetic fields in the cores of red giant stars can be identified with asteroseismology. ... More
Gap interpolation by inpainting methods : Application to Ground and Space-based Asteroseismic dataOct 22 2014In asteroseismology, the observed time series often suffers from incomplete time coverage due to gaps. The presence of periodic gaps may generate spurious peaks in the power spectrum that limit the analysis of the data. Various methods have been developed ... More
Clues to the nature of ultra diffuse galaxies from estimated galaxy velocity dispersionsSep 26 2016We describe how to estimate the velocity dispersions of ultra diffuse galaxies, UDGs, using a previously defined galaxy scaling relationship. The method is accurate for the two UDGs with spectroscopically measured dispersions, as well as for ultra compact ... More
The excess formula in functorial formMay 01 2012This article is motivated by the need for better understanding of refined Riemann-Roch theorems and the behavior of the determinant of the cohomology. This poses a certain problem of functoriality and can be understood as that of giving refined constructions ... More
The club of simplicial setsJan 13 2010Dec 15 2010A club structure is defined on the category of simplicial sets. This club generalizes the operad of associative rings by adding "amalgamated" products.
Degenerating Riemann surfaces and the Quillen metricJun 15 2011The degeneration of the Quillen metric for a one-parameter family of Riemann surfaces has been studied by Bismut-Bost and Yoshikawa. In this article we propose a more geometric point of view using Deligne's Riemann-Roch theorem. We obtain an interpretation ... More
The Michelson-Morley experiment in an accelerated reference frameDec 15 2010We analyze the Michelson-Morley experiment in a reference frame moving with constant proper acceleration. Interestingly, we find an expected fringe shift which depends not only on the interferometer's rate of acceleration, but also on its speed relative ... More
Non-Markovian Beables vs. Massive ParallelismMar 16 2010A simple dynamical model over a discrete classical state space is presented. In a certain limit, it reduces to one in a class of models subsuming Bell's field-theoretic version of Bohmian mechanics. But it exhibits the massive parallelism native to quantum ... More
Construction of central elements in the affine Hecke algebra via nearby cyclesDec 09 1999Oct 27 2000Let $G$ be a reductive group, let $Gr=G((t))/G[[t]]$ be the corresponding affine Grassmannian and let $Fl=G((t))/I$ be the affine flag variety. We construct, following an idea of Belinson, a 1-parametric deformation of the product $Gr\times G/B$ to $Fl$. ... More
Notes on 2D Conformal Field Theory and String TheoryNov 09 1998May 27 1999We explain the basics of conformal theory using the language of chiral algebras of Beilinson and Drinfeld.
Sheaves of categories and the notion of 1-affinenessJun 18 2013Aug 10 2014We define the notion of 1-affineness for a prestack, and prove an array of results that establish 1-affineness of certain types of prestacks.