Results for "Yvonne W Lui"

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Identifying Mild Traumatic Brain Injury Patients From MR Images Using Bag of Visual WordsOct 18 2017Feb 14 2018Mild traumatic brain injury (mTBI) is a growing public health problem with an estimated incidence of one million people annually in US. Neurocognitive tests are used to both assess the patient condition and to monitor the patient progress. This work aims ... More
MTBI Identification From Diffusion MR Images Using Bag of Adversarial Visual FeaturesJun 27 2018In this work, we propose bag of adversarial features (BAF) for identifying mild traumatic brain injury (MTBI) patients from their diffusion magnetic resonance images (MRI) (obtained within one month of injury) by incorporating unsupervised feature learning ... More
Training a Neural Network for Gibbs and Noise Removal in Diffusion MRIMay 10 2019May 15 2019We develop and evaluate a neural network-based method for Gibbs artifact and noise removal. A convolutional neural network (CNN) was designed for artifact removal in diffusion-weighted imaging data. Two implementations were considered: one for magnitude ... More
Bianchi - Euler system for relativistice fluids and Bel - Robinson type energyJun 29 2002We write a first order symmetric hyperbolic system coupling the Riemann with the dynamical acceleration of a relativistic fluid. W determine the associated, coupled, Bel - Robinson energy, and the integral equality that it satisfies.
Einstein Bianchi equations with sourcesNov 07 2005In this article, dedicated to one of the best specialist of the FOSH systems, we couple the Bianchi equations with the equations satisfied by the dynamical acceleration of a charged fluid and the derivatives of the associated Maxwell field.
Einstein-Bianchi Hyperbolic System for General RelativityOct 07 1997Feb 26 1998By employing the Bianchi identities for the Riemann tensor in conjunction with the Einstein equations, we construct a first order symmetric hyperbolic system for the evolution part of the Cauchy problem of general relativity. In this system, the metric ... More
An Effective Compactness Theorem for Coxeter GroupsFeb 16 2009Through highly non-constructive methods, works by Bestvina, Culler, Feighn, Morgan, Paulin, Rips, Shalen, and Thurston show that if a finitely presented group does not split over a virtually solvable subgroup, then the space of its discrete and faithful ... More
An algorithm for computing the canonical bases of higher-level q-deformed Fock spacesSep 14 2006Dec 12 2006We derive a straightening-free algorithm that computes the canonical bases of any higher-level q-deformed Fock space.
Tevatron LegacyFeb 28 2012Several major milestones and discoveries were attained during the lifetime of the Tevatron proton-antiproton collider at Fermilab, from 1987 to 2011. One of the most important was the discovery of the top quark in 1995, followed by an intense program ... More
fastMRI: An Open Dataset and Benchmarks for Accelerated MRINov 21 2018Accelerating Magnetic Resonance Imaging (MRI) by taking fewer measurements has the potential to reduce medical costs, minimize stress to patients and make MRI possible in applications where it is currently prohibitively slow or expensive. We introduce ... More
On reconstruction of dynamic permeability and tortuosity from data at distinct frequenciesNov 13 2013May 28 2014This article focuses on the mathematical problem of reconstructing dynamic permeability $K(\omega)$ of two-phase composites from data at different frequencies, utilizing the analytic structure of the Stieltjes function representation of $K(\omega)$ derived ... More
Two-Loop Scattering Amplitudes from Ambitwistor Strings: from Genus Two to the Nodal Riemann SphereMay 14 2018Dec 17 2018We derive from ambitwistor strings new formulae for two-loop scattering amplitudes in supergravity and super-Yang-Mills theory, with any number of particles. We start by constructing a formula for the type II ambitwistor string amplitudes on a genus-two ... More
Neutrino mass in cosmology: status and prospectsNov 06 2011I give an overview of the effects of neutrino masses in cosmology, focussing on the role they play in the evolution of cosmological perturbations. I discuss how recent observations of the cosmic microwave background anisotropies and the large-scale matter ... More
Derived invariants for surface algebrasNov 03 2014Mar 25 2016In this paper we study the derived equivalences between surface algebras, introduced by David-Roesler and Schiffler. Each surface algebra arises from a cut of an ideal triangulation of an unpunctured marked Riemann surface with boundary. A cut can be ... More
Gluons and gravitons at one loop from ambitwistor stringsNov 27 2017Mar 09 2018We present new and explicit formulae for the one-loop integrands of scattering amplitudes in non-supersymmetric gauge theory and gravity, valid for any number of particles. The results exhibit the colour-kinematics duality in gauge theory and the double-copy ... More
Keller's Theorem RevisitedAug 21 2017Keller's theorem relates the components of the macroscopic dielectric response of a binary two-dimensional composite system with those of the reciprocal system obtained by interchanging its components. We present a derivation of the theorem that, unlike ... More
Continued fractions and irrationality exponents for modified Engel and Pierce seriesOct 23 2018An Engel series is a sum of reciprocals of a non-decreasing sequence $(x_n)$ of positive integers, which is such that each term is divisible by the previous one, and a Pierce series is an alternating sum of the reciprocals of a sequence with the same ... More
Probing Strong Field Gravity Through Numerical SimulationsFeb 24 2015This article is an overview of the contributions numerical relativity has made to our understanding of strong field gravity, to be published in the book "General Relativity and Gravitation: A Centennial Perspective", commemorating the 100th anniversary ... More
Thermopower of Graphene Nanoribbons in the Pseudodiffusive RegimeSep 08 2018Thermoelectric measurements for graphene ribbons are currently performed on samples that include atomic disorder via defects and irregular edges. In this work, we investigate the thermopower or Seebeck coefficient of graphene ribbons within the linear ... More
Future Global in time einsteinian spacetimes with U(1) isometry groupDec 19 2001We prove that spacetimes satisfying the vacuum Einstein equations on a manifold of the form $\Sigma \times U(1)\times R$ where $\Sigma $ is a compact surface of genus $G>1$ and where the Cauchy data is invariant with respect to U(1) and sufficiently small ... More
Global Hyperbolicity and CompletenessJan 17 2002Jan 21 2002We prove global hyperbolicity of spacetimes under generic regularity conditions on the metric. We then show that these spacetimes are timelike and null geodesically complete if the gradient of the lapse and the extrinsic curvature $K$ are integrable. ... More
A Search for "Dwarf" Seyfert Nuclei. V. Demographics of Nuclear Activity in Nearby GalaxiesApr 11 1997We use the sample of emission-line nuclei derived from a recently completed optical spectroscopic survey of nearby galaxies to quantify the incidence of local (z = 0) nuclear activity. Consistent with previous studies, we find detectable amounts of ionized ... More
Dendriform-Tree Setting for Fully Non-commutative Fliess OperatorsAug 29 2014This paper provides a dendriform-tree setting for Fliess operators with matrix-valued inputs. This class of analytic nonlinear input-output systems is convenient, for example, in quantum control. In particular, a description of such Fliess operators is ... More
Discrete-Time Approximations of Fliess OperatorsOct 24 2015A convenient way to represent a nonlinear input-output system in control theory is via a Chen-Fliess functional expansion or Fliess operator. The general goal of this paper is to describe how to approximate Fliess operators with iterated sums and to provide ... More
Faa di Bruno Hopf Algebra of the Output Feedback Group for Multivariable Fliess OperatorsJun 20 2014Nov 01 2014Given two nonlinear input-output systems written in terms of Chen-Fliess functional expansions, it is known that the feedback interconnected system is always well defined and in the same class. An explicit formula for the generating series of a single-input, ... More
Diffusion Variational AutoencodersJan 25 2019A standard Variational Autoencoder, with a Euclidean latent space, is structurally incapable of capturing topological properties of certain datasets. To remove topological obstructions, we introduce Diffusion Variational Autoencoders with arbitrary manifolds ... More
Combinatorial Hopf algebra for interconnected nonlinear systemsMay 08 2018A detailed expose of the Hopf algebra approach to interconnected input-output systems in nonlinear control theory is presented. The focus is on input-output systems that can been represented in terms of Chen-Fliess functional expansions or Fliess operators. ... More
The Influence of Bars on Nuclear ActivityApr 11 1997We test ideas on fueling of galactic nuclei by bar-driven inflow by comparing the detection rate and intensity of nuclear H II regions and AGNs among barred and unbarred galaxies in a sample of over 300 spirals selected from our recent optical spectroscopic ... More
Second-Harmonic Generation in Nano-Structured MetamaterialsDec 14 2018We conduct a theoretical and numerical study on the second-harmonic (SH) optical response of a nano-structured metamaterial composed of a periodic array of inclusions. Both the inclusions and their surrounding matrix are made of centrosymmetrical materials, ... More
Cauchy problem with data on a characteristic cone for the Einstein-Vlasov equationsJun 02 2012We show how to solve the Cauchy problem for the Einstein-Vlasov equations with geometric initial data on a light-cone.
T-violation in flavour oscillations as a test for relativity principles at a neutrino factoryJan 23 2003Feb 05 2003We study the effects of violation of the equivalence principle (VEP) or violation of Lorentz invariance (LIV) in the neutrino sector on the asymmetry between T-conjugate oscillation probabilities, $\Delta P_T \equiv P(\nu_{\alpha} \to \nu_{\beta}) - P(\nu_{\beta} ... More
Presence of mixed modes in red giants in binary systemsMay 31 2017The frequencies of oscillation modes in stars contain valuable information about the stellar properties. In red giants the frequency spectrum also contains mixed modes, with both pressure (p) and gravity (g) as restoring force, which are key to understanding ... More
Higher-order massive neutrino perturbations in large-scale structureDec 08 2014Mar 03 2015We develop a higher-order perturbation theory for large-scale structure formation involving a free-streaming hot or warm dark matter species. We focus on the case of mixed cold dark matter and massive neutrinos, although our approach is applicable also ... More
Gravitational clustering of relic neutrinos and implications for their detectionAug 23 2004Nov 24 2004We study the gravitational clustering of big bang relic neutrinos onto existing cold dark matter (CDM) and baryonic structures within the flat $\Lambda$CDM model, using both numerical simulations and a semi-analytical linear technique, with the aim of ... More
When Can a Distributed Ledger Replace a Trusted Third Party?Jun 28 2018The functionality that distributed ledger technology provides, i.e., an immutable and fraud-resistant registry with validation and verification mechanisms, has traditionally been implemented with a trusted third party. Due to the distributed nature of ... More
Top Quark Physics at the TevatronFeb 14 2013Mar 26 2013The heaviest known elementary particle, the top quark, was discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton-antiproton collider at Fermilab. Since its discovery, a large program was set in motion by the CDF and D0 collaborations ... More
The post-AGB evolution of AGB mass loss variationsMay 20 2003We present new numerical hydrodynamical modelling of the evolution of Asymptotic Giant Branch (AGB) mass loss fluctuations during the post-AGB/Planetary Nebula phase. These models show that after ionization, the observable effects of the mass loss fluctuations ... More
Intuitive Source Code Visualization Tools for Improving Student Comprehension: BRICSMar 04 2008Even relatively simple code analysis can be a daunting task for many first year students. Perceived complexity, coupled with foreign and harsh syntax, often outstrips the ability for students to take in what they are seeing in terms of their verbal memory. ... More
Solar Irradiance VariabilityOct 22 2012The Sun has long been considered a constant star, to the extent that its total irradiance was termed the solar constant. It required radiometers in space to detect the small variations in solar irradiance on timescales of the solar rotation and the solar ... More
Measurement and Control of Quasiparticle Dynamics in a Superconducting QubitJun 27 2014Oct 24 2014Superconducting circuits have attracted growing interest in recent years as a promising candidate for fault-tolerant quantum information processing. Extensive efforts have always been taken to completely shield these circuits from external magnetic field ... More
A Deep Unsupervised Learning Approach Toward MTBI Identification Using Diffusion MRIFeb 08 2018Mild traumatic brain injury (mTBI) is a growing public health problem with an estimated incidence of one million people annually in US. Neurocognitive tests have been used to both assess the patient condition and to monitor the patient progress. This ... More
A Machine Learning Approach For Identifying Patients with Mild Traumatic Brain Injury Using Diffusion MRI ModelingAug 27 2017While diffusion MRI has been extremely promising in the study of MTBI, identifying patients with recent MTBI remains a challenge. The literature is mixed with regard to localizing injury in these patients, however, gray matter such as the thalamus and ... More
A Deep Unsupervised Learning Approach Toward MTBI Identification Using Diffusion MRIFeb 08 2018Apr 11 2018Mild traumatic brain injury is a growing public health problem with an estimated incidence of over 1.7 million people annually in US. Diagnosis is based on clinical history and symptoms, and accurate, concrete measures of injury are lacking. This work ... More
Large Scale Flows from Orion-SouthJan 22 2007Multiple optical outflows are known to exist in the vicinity of the active star formation region called Orion-South (Orion-S). We have mapped the velocity of low ionization features in the brightest part of the Orion Nebula, including Orion-S, and imaged ... More
Single Top Quark Production at the TevatronOct 26 2012While the heaviest known elementary particle, the top quark, has been discovered in 1995 by the CDF and D0 collaborations in ttbar events, it took 14 more years until the observation of single top quark production. In this article, we discuss recent studies ... More
Top Quark Pair Production Cross Section at the TevatronSep 25 2015The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production ... More
Iterated smoothed bootstrap confidence intervals for population quantilesApr 25 2005This paper investigates the effects of smoothed bootstrap iterations on coverage probabilities of smoothed bootstrap and bootstrap-t confidence intervals for population quantiles, and establishes the optimal kernel bandwidths at various stages of the ... More
Einstein constraints on a characteristic coneFeb 07 2010We analyse the Cauchy problem on a characteristic cone, including its vertex, for the Einstein equations in arbitrary dimensions. We use a wave map gauge, solve the obtained constraints and show gauge conservation.
The light-cone theoremMay 13 2009Jun 11 2009We prove that the area of cross-sections of light-cones, in space-times satisfying suitable energy conditions, is smaller than or equal to that of the corresponding cross-sections in Minkowski, or de Sitter, or anti-de Sitter space-time. The equality ... More
Top Quark Mass Measurements at the TevatronSep 23 2013Since the discovery of the top quark in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron proton antiproton collider, precise measurements of its mass are ongoing. Using data recorded by the D0 and CDF experiment, corresponding to up to the ... More
High-Resolution Finite Volume Modeling of Wave Propagation in Orthotropic Poroelastic MediaMay 25 2012Nov 27 2012Poroelasticity theory models the dynamics of porous, fluid-saturated media. It was pioneered by Maurice Biot in the 1930s through 1960s, and has applications in several fields, including geophysics and modeling of in vivo bone. A wide variety of methods ... More
An in-depth study of grid-based asteroseismic analysisSep 15 2010Jan 20 2011NASA's Kepler mission is providing basic asteroseismic data for hundreds of stars. One of the more common ways of determining stellar characteristics from these data is by so-called "grid based" modelling. We have made a detailed study of grid-based analysis ... More
Control of an Architectural Cable Net GeometryAug 15 2018Doubly curved thin concrete shells are very efficient building structures, suitable for light-weight construction because of their high structural stability. In the process of constructing such shells, an efficient innovative flexible formwork that is ... More
Evidence for dark matter modulation in CoGeNT?Nov 14 2011Jan 30 2012We investigate the question of whether the recent modulation signal claimed by CoGeNT is best explained by the dark matter (DM) hypothesis from a Bayesian model comparison perspective. We consider five phenomenological explanations for the data: no modulation ... More
Getting leverage on inflation with a large photometric redshift surveySep 11 2014We assess the potential of a future large-volume photometric redshift survey to constrain observational inflationary parameters using three large-scale structure observables: the angular shear and galaxy power spectra, and the cluster mass function measured ... More
Knowledge Acquisition for Content SelectionFeb 24 1997An important part of building a natural-language generation (NLG) system is knowledge acquisition, that is deciding on the specific schemas, plans, grammar rules, and so forth that should be used in the NLG system. We discuss some experiments we have ... More
Using CMB spectral distortions to distinguish between dark matter solutions to the small-scale crisisJul 21 2017Sep 12 2017The dissipation of small-scale perturbations in the early universe produces a distortion in the blackbody spectrum of cosmic microwave background photons. In this work, we propose to use these distortions as a probe of the microphysics of dark matter ... More
A discontinuous Galerkin method for wave propagation in orthotropic poroelastic media with memory termsNov 22 2018In this paper, we investigate wave propagation in orthotropic poroelastic media by studying the time-domain poroelastic equations. Both the low frequency Biot's (LF-Biot) equations and the Biot-Johnson-Koplik-Dashen (Biot-JKD) models are considered. In ... More
Regularity results for nonlocal equations by approximationFeb 23 2009Mar 30 2010In this paper we prove a nonlocal version of the Cordes-Niremberg estimates. We use it to extend our previous regularity results for fully nonlinear integro-differential equations to the variable coefficient case and several other settings where the equation ... More
Regularity theory for fully nonlinear integro-differential equationsSep 28 2007Apr 26 2008We consider nonlinear integro-differential equations, like the ones that arise from stochastic control problems with purely jump L\`evy processes. We obtain a nonlocal version of the ABP estimate, Harnack inequality, and interior $C^{1,\alpha}$ regularity ... More
From Caesar to Twitter: An Axiomatic Approach to Elites of Social NetworksNov 14 2011Nov 27 2012In many societies there is an elite, a relatively small group of powerful individuals that is well-connected and highly influential. Since the ancient days of Julius Caesar's senate of Rome to the recent days of celebrities on Twitter, the size of the ... More
Top Quark Properties at the TeVatronMar 29 2011Discovered in 1995 by CDF and D0 at the Fermilab Tevatron collider, the top quark remains interesting to test the Standard Model. Having collected more than 7 fb$^{-1}$ of integrated luminosity with both experiments until today, several top quark properties ... More
Simultaneous Acoustic Localization of Multiple Smartphones with Euclidean Distance MatricesDec 16 2015In this paper, we present an acoustic localization system for multiple devices. In contrast to systems which localise a device relative to one or several anchor points, we focus on the joint localisation of several devices relative to each other. We present ... More
The unexplored landscape of two-body resonancesOct 28 2016We propose a strategy for searching for theoretically-unanticipated new physics which avoids a large trials factor by focusing on experimental strengths. Searches for resonances decaying into pairs of visible particles are experimentally very powerful ... More
Algebraic and combinatorial aspects of sandpile monoids on directed graphsMay 12 2011Aug 17 2012The sandpile group of a graph is a well-studied object that combines ideas from algebraic graph theory, group theory, dynamical systems, and statistical physics. A graph's sandpile group is part of a larger algebraic structure on the graph, known as its ... More
Macroscopic optical response and photonic bandsDec 21 2012We develop a formalism for the calculation of the macroscopic dielectric response of composite systems made of particles of one material embedded periodically within a matrix of another material, each of which is characterized by a well defined dielectric ... More
Bloch-Like Quantum Multiple Reflections of AtomsNov 14 1998We show that under certain circumstances an atom can follow an oscillatory motion in a periodic laser profile with a Gaussian envelope. These oscillations can be well explained by using a model of energetically forbidden spatial regions. The similarities ... More
The Evans-Krylov theorem for non local fully non linear equationsMay 08 2009We prove an interior regularity result for solutions of a purely integro-differential Bellman equation. This regularity is enough for the solutions to be understood in the classical sense. If we let the order of the equation approach two, we recover the ... More
The Many Faces of Graph DynamicsAug 05 2016The topological structure of complex networks has fascinated researchers for several decades, resulting in the discovery of many universal properties and reoccurring characteristics of different kinds of networks. However, much less is known today about ... More
Top quark Physics at the TevatronJan 06 2012When the heaviest elementary particle known today, the top quark, was discovered in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, a large program to study this particle in details has started. In this article, an overview of ... More
One-loop amplitudes on the Riemann sphereNov 19 2015Mar 16 2016The scattering equations provide a powerful framework for the study of scattering amplitudes in a variety of theories. Their derivation from ambitwistor string theory led to proposals for formulae at one loop on a torus for 10 dimensional supergravity, ... More
Two-Loop Scattering Amplitudes from the Riemann SphereJul 29 2016The scattering equations give striking formulae for massless scattering amplitudes at tree level and, as shown recently, at one loop. The progress at loop level was based on ambitwistor string theory, which naturally yields the scattering equations. We ... More
A Search for "Dwarf" Seyfert Nuclei. VII. A Catalog of Central Stellar Velocity Dispersions of Nearby GalaxiesJun 22 2009We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being relatively late-type systems with low ... More
Effective Dielectric Response of MetamaterialsJan 22 2009Jun 18 2009We use a homogenization procedure for Maxwell's equations in order to obtain in the local limit the frequency ($\omega$) dependent macroscopic dielectric response $\epsilon^M(\omega)$ of metamaterials made of natural constituents with any geometrical ... More
Central Structural Parameters of Early-Type Galaxies as Viewed with HST/NICMOSMay 22 2001We present surface photometry for the central regions of a sample of 33 early-type (E, S0, and S0/a) galaxies observed at 1.6 microns (H band) using the Hubble Space Telescope (HST). We employ a new technique of two-dimensional fitting to extract quantitative ... More
Optical and Electrical Properties of Nanostructured Metallic Electrical ContactsSep 15 2016We study the optical and electrical properties of silver films with a graded thickness obtained through metallic evaporation in vacuum on a tilted substrate to evaluate their use as semitransparent electrical contacts. We measure their ellipsometric coefficients, ... More
Discovery of Radio Outbursts in the Active Nucleus of M81May 06 1999The low-luminosity active galactic nucleus of M81 has been monitored at centimeter wavelengths since early 1993 as a by-product of radio programs to study the radio emission from Supernova 1993J. The extensive data sets reveal that the nucleus experienced ... More
The Central Regions of Early-Type Galaxies Hosting Active Galactic Nuclei as Viewed with HST/NICMOSFeb 28 2001We present preliminary results from surface photometry of a sample of early-type galaxies observed with NICMOS on board HST in the F160W (H-band) filter. Dust is found to occur mostly in galaxies which possess unresolved nuclei, and in a few cases the ... More
A Search for "Dwarf" Seyfert Nuclei. IV. Nuclei with Broad H-alpha EmissionApr 11 1997We present the results of an optical spectroscopic survey designed to search for low-luminosity, "dwarf" Seyfert nuclei in a magnitude-limited sample of 486 bright, northern galaxies. Moderate-resolution spectra of exceptionally high quality were obtained ... More
Non-line-of-sight Node Localization based on Semi-Definite Programming in Wireless Sensor NetworksDec 31 2009An unknown-position sensor can be localized if there are three or more anchors making time-of-arrival (TOA) measurements of a signal from it. However, the location errors can be very large due to the fact that some of the measurements are from non-line-of-sight ... More
An Architecture for Person-Following using Active Target SearchSep 24 2018This paper addresses a novel architecture for person-following robots using active search. The proposed system can be applied in real-time to general mobile robots for learning features of a human, detecting and tracking, and finally navigating towards ... More
A non local Monge-Ampere equationOct 01 2014Jun 26 2015We introduce a non local analog to the Monge-Ampere operator and show some of its properties. We prove that a global problem involving this operator has C 1,1 solutions in the full space.
On the Evans-Krylov theoremMay 08 2009Sep 08 2010In this note, motivated by our work on integral fully nonlinear equations, we provide a variation of the proof of Evans-Krylov theorem about the interior $C^{2,\alpha}$ a priori estimate for concave fully nonlinear elliptic equations. The proof we present ... More
Training a Neural Network for Gibbs and Noise Removal in Diffusion MRIMay 10 2019We develop and evaluate a neural network-based method for Gibbs artifact and noise removal. A convolutional neural network (CNN) was designed for artifact removal in diffusion-weighted imaging data. Two implementations were considered: one for magnitude ... More
Kepler-93b: A Terrestrial World Measured to within 120 km, and a Test Case for a New Spitzer Observing ModeMay 14 2014We present the characterization of the Kepler-93 exoplanetary system, based on three years of photometry gathered by the Kepler spacecraft. The duration and cadence of the Kepler observations, in tandem with the brightness of the star, enable unusually ... More
On H. Friedrich's formulation of Einstein'equations with fluid sourcesFeb 05 2002We establish a variant, which has the advantage of introducing only physical characteristics, of the symmetric quasi linear first order system given by H.\ Friedrich for the evolution equations of gravitating fluid bodies in General Relativity which can ... More
Constraints and evolution in cosmologyFeb 05 2002We review some old and new results about strict and non strict hyperbolic formulations of the Einstein equations.
From potential modularity to modularity for integral Galois representations and rigid Calabi-Yau threefoldsSep 07 2004We prove modularity for any irreducible crystalline $\ell$-adic odd 2-dimensional Galois representation (with finite ramification set) unramified at 3 verifying an "ordinarity at 3" easy to check condition, with Hodge-Tate weights $\{0, w \}$ such that ... More
Galois characterization of Endoscopy for rational Siegel modular formsOct 16 2003We establish a relation between Galois reducibility and Endoscopy for genus 2 Siegel cusp forms which have rational eigenvalues and are unramified at 3
Modular congruences, Q-curves, and the diophantine equation x^4 + y^4 = z^pApr 27 2003We prove two results concerning the generalized Fermat equation $x^4+y^4=z^p$. In particular we prove that the First Case is true if $p \neq 7$.
Nilpotent Types and Fracture Squares in Homotopy Type TheoryMar 08 2019We develop the basic theory of nilpotent types and their localizations away from sets of numbers in Homotopy Type Theory. For this, general results about the classifying spaces of fibrations with fiber an Eilenberg-Mac Lane space are proven. We also construct ... More
Uniform behavior of families of Galois representations on Siegel modular forms and the Endoscopy ConjectureApr 27 2003Apr 30 2007We prove the following uniformity principle: if one of the Galois representations in the family attached to a genus two Siegel cusp form of weight $k>3$, "semistable" and with multiplicity one, is reducible (for an odd prime $p$),then all the representations ... More
Instabilities in neutrino-plasma density wavesJan 05 2001Apr 08 2001One examines the interaction and possible resonances between supernova neutrinos and electron plasma waves. The neutrino phase space distribution and its boundary regions are analyzed in detail. It is shown that the boundary regions are too wide to produce ... More
Breaking the weak Heisenberg limitJul 26 2016We provide a very simple analytical and numerical case showing that the weak form of the Heisenberg limit can be beaten while the prior information is improved without bias problems.
Using Barriers to Reduce the Sensitivity to Edge Miscalculations of Casting-Based Object Projection Feature EstimationMar 01 20123D motion tracking is a critical task in many computer vision applications. Unsupervised markerless 3D motion tracking systems determine the most relevant object in the screen and then track it by continuously estimating its projection features (center ... More
Holder estimates for advection fractional-diffusion equationsSep 29 2010Apr 22 2011We analyse conditions for an evolution equation with a drift and fractional diffusion to have a Holder continuous solution. In case the diffusion is of order one or more, we obtain Holder estimates for the solution for any bounded drift. In the case when ... More
Numerical Relativity: A reviewJun 22 2001Jun 29 2001Computer simulations are enabling researchers to investigate systems which are extremely difficult to handle analytically. In the particular case of General Relativity, numerical models have proved extremely valuable for investigations of strong field ... More
Continuous Charge Modulated Diagonal Phase in ManganitesOct 15 2003We present a novel ground state that explain the continuous modulated charge diagonal order recently observed in manganese oxides, at hole densities $x$ larger than one half. In this diagonal phase the charge is modulated with a predominant Fourier component ... More
An asymptotically optimal Bernoulli factory for certain functions that can be expressed as power seriesDec 28 2016Dec 18 2018Given a sequence of independent Bernoulli variables with unknown parameter $p$, and a function $f$ expressed as a power series with non-negative coefficients that sum to at most $1$, an algorithm is presented that produces a Bernoulli variable with parameter ... More
Langlands Base Change for GL(2)Dec 10 2009Jun 16 2011Let F be a totally real Galois number field. We prove the existence of base change relative to the extension F/Q for every classical newform of odd level, under simple local assumptions on the field F.