Results for "M. A. Viergever"

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Dilated Convolutional Neural Networks for Cardiovascular MR Segmentation in Congenital Heart DiseaseApr 12 2017We propose an automatic method using dilated convolutional neural networks (CNNs) for segmentation of the myocardium and blood pool in cardiovascular MR (CMR) of patients with congenital heart disease (CHD). Ten training and ten test CMR scans cropped ... More
Automatic Segmentation and Disease Classification Using Cardiac Cine MR ImagesAug 03 2017Segmentation of the heart in cardiac cine MR is clinically used to quantify cardiac function. We propose a fully automatic method for segmentation and disease classification using cardiac cine MR images. A convolutional neural network (CNN) was designed ... More
Generative adversarial network for segmentation of motion affected neonatal brain MRIJun 11 2019Automatic neonatal brain tissue segmentation in preterm born infants is a prerequisite for evaluation of brain development. However, automatic segmentation is often hampered by motion artifacts caused by infant head movements during image acquisition. ... More
Vertebra partitioning with thin-plate spline surfaces steered by a convolutional neural networkJul 25 2019Thin-plate splines can be used for interpolation of image values, but can also be used to represent a smooth surface, such as the boundary between two structures. We present a method for partitioning vertebra segmentation masks into two substructures, ... More
A Recurrent CNN for Automatic Detection and Classification of Coronary Artery Plaque and Stenosis in Coronary CT AngiographyApr 12 2018Dec 10 2018Various types of atherosclerotic plaque and varying grades of stenosis could lead to different management of patients with coronary artery disease. Therefore, it is crucial to detect and classify the type of coronary artery plaque, as well as to detect ... More
Automated characterization of noise distributions in diffusion MRI dataJun 28 2019Purpose: To understand and characterize noise distributions in parallel imaging for diffusion MRI. Theory and Methods: Two new automated methods using the moments and the maximum likelihood equations of the Gamma distribution were developed. Simulations ... More
Automated characterization of noise distributions in diffusion MRI dataJun 28 2019Aug 15 2019Knowledge of the noise distribution in diffusion MRI is the centerpiece to quantify uncertainties arising from the acquisition process. Accurate estimation beyond textbook distributions often requires information about the acquisition process, which is ... More
Coronary Artery Centerline Extraction in Cardiac CT Angiography Using a CNN-Based Orientation ClassifierOct 07 2018Oct 24 2018Coronary artery centerline extraction in cardiac CT angiography (CCTA) images is a prerequisite for evaluation of stenoses and atherosclerotic plaque. We propose an algorithm that extracts coronary artery centerlines in CCTA using a convolutional neural ... More
ConvNet-Based Localization of Anatomical Structures in 3D Medical ImagesApr 19 2017Localization of anatomical structures is a prerequisite for many tasks in medical image analysis. We propose a method for automatic localization of one or more anatomical structures in 3D medical images through detection of their presence in 2D image ... More
Automatic segmentation of MR brain images with a convolutional neural networkApr 11 2017Automatic segmentation in MR brain images is important for quantitative analysis in large-scale studies with images acquired at all ages. This paper presents a method for the automatic segmentation of MR brain images into a number of tissue classes using ... More
Deep learning analysis of the myocardium in coronary CT angiography for identification of patients with functionally significant coronary artery stenosisNov 24 2017Dec 06 2017In patients with coronary artery stenoses of intermediate severity, the functional significance needs to be determined. Fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA), is most often used in clinical practice. ... More
Deep learning analysis of cardiac CT angiography for detection of coronary arteries with functionally significant stenosisJun 11 2019In patients with obstructive coronary artery disease, the functional significance of a coronary artery stenosis needs to be determined to guide treatment. This is typically established through fractional flow reserve (FFR) measurement, performed during ... More
Reducing variability in along-tract analysis with diffusion profile realignmentFeb 04 2019Mar 27 2019Diffusion weighted MRI (dMRI) provides a non invasive virtual reconstruction of the brain's white matter structures through tractography. Analyzing dMRI measures along the trajectory of white matter bundles can provide a more specific investigation than ... More
Reducing variability in along-tract analysis with diffusion profile realignmentFeb 04 2019May 08 2019Diffusion weighted MRI (dMRI) provides a non invasive virtual reconstruction of the brain's white matter structures through tractography. Analyzing dMRI measures along the trajectory of white matter bundles can provide a more specific investigation than ... More
Direct Prediction of Cardiovascular Mortality from Low-dose Chest CT using Deep LearningOct 04 2018Cardiovascular disease (CVD) is a leading cause of death in the lung cancer screening population. Chest CT scans made in lung cancer screening are suitable for identification of participants at risk of CVD. Existing methods analyzing CT images from lung ... More
Reducing variability in along-tract analysis with diffusion profile realignmentFeb 04 2019Diffusion weighted MRI (dMRI) provides a non invasive virtual reconstruction of the brain's white matter structures through tractography. Analyzing dMRI measures along the trajectory of white matter bundles can provide a more specific investigation than ... More
Reducing variability in along-tract analysis with diffusion profile realignmentFeb 04 2019Mar 29 2019Diffusion weighted MRI (dMRI) provides a non invasive virtual reconstruction of the brain's white matter structures through tractography. Analyzing dMRI measures along the trajectory of white matter bundles can provide a more specific investigation than ... More
SMART tracking: Simultaneous anatomical imaging and real-time passive device tracking for MR-guided interventionsAug 28 2019Purpose: This study demonstrates a proof of concept of a method for simultaneous anatomical imaging and real-time (SMART) passive device tracking for MR-guided interventions. Methods: Phase Correlation template matching was combined with a fast undersampled ... More
Deep Learning for Multi-Task Medical Image Segmentation in Multiple ModalitiesApr 11 2017Automatic segmentation of medical images is an important task for many clinical applications. In practice, a wide range of anatomical structures are visualised using different imaging modalities. In this paper, we investigate whether a single convolutional ... More
Automatic brain tissue segmentation in fetal MRI using convolutional neural networksJun 11 2019MR images of fetuses allow clinicians to detect brain abnormalities in an early stage of development. The cornerstone of volumetric and morphologic analysis in fetal MRI is segmentation of the fetal brain into different tissue classes. Manual segmentation ... More
Automatic segmentation of the intracranialvolume in fetal MR imagesJul 31 2017MR images of the fetus allow non-invasive analysis of the fetal brain. Quantitative analysis of fetal brain development requires automatic brain tissue segmentation that is typically preceded by segmentation of the intracranial volume (ICV). This is challenging ... More
Direct and Real-Time Cardiovascular Risk PredictionDec 08 2017Coronary artery calcium (CAC) burden quantified in low-dose chest CT is a predictor of cardiovascular events. We propose an automatic method for CAC quantification, circumventing intermediate segmentation of CAC. The method determines a bounding box around ... More
End-to-End Unsupervised Deformable Image Registration with a Convolutional Neural NetworkApr 20 2017In this work we propose a deep learning network for deformable image registration (DIRNet). The DIRNet consists of a convolutional neural network (ConvNet) regressor, a spatial transformer, and a resampler. The ConvNet analyzes a pair of fixed and moving ... More
Automatic, fast and robust characterization of noise distributions for diffusion MRIMay 30 2018Oct 02 2018Knowledge of the noise distribution in magnitude diffusion MRI images is the centerpiece to quantify uncertainties arising from the acquisition process. The use of parallel imaging methods, the number of receiver coils and imaging filters applied by the ... More
A Deep Learning Framework for Unsupervised Affine and Deformable Image RegistrationSep 17 2018Dec 05 2018Image registration, the process of aligning two or more images, is the core technique of many (semi-)automatic medical image analysis tasks. Recent studies have shown that deep learning methods, notably convolutional neural networks (ConvNets), can be ... More
Automatic Segmentation of the Left Ventricle in Cardiac CT Angiography Using Convolutional Neural NetworkApr 19 2017Accurate delineation of the left ventricle (LV) is an important step in evaluation of cardiac function. In this paper, we present an automatic method for segmentation of the LV in cardiac CT angiography (CCTA) scans. Segmentation is performed in two stages. ... More
Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutionsNov 01 2017Feb 01 2018Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification ... More
Assessment of algorithms for mitosis detection in breast cancer histopathology imagesNov 21 2014The proliferative activity of breast tumors, which is routinely estimated by counting of mitotic figures in hematoxylin and eosin stained histology sections, is considered to be one of the most important prognostic markers. However, mitosis counting is ... More
Standardized Assessment of Automatic Segmentation of White Matter Hyperintensities and Results of the WMH Segmentation ChallengeApr 01 2019Quantification of cerebral white matter hyperintensities (WMH) of presumed vascular origin is of key importance in many neurological research studies. Currently, measurements are often still obtained from manual segmentations on brain MR images, which ... More
Polynomial Differential Equations with Small coefficientsApr 17 2009Classes of polynomial differential equations of degree n are considered. An explicit upper bound on the size of the coefficients are given which implies that each equation in the class has exactly n complex periodic solutions. In most of the classes the ... More
Periodic Solutions of Abel Differential EquationsMay 05 2006Jun 09 2006For a class of polynomial non-autonomous differential equations of degree n, we use phase plane analysis to show that each equation in this class has n periodic solutions. The result implies that certain rigid two-dimensional systems have at most one ... More
Complex Centers of Polynomial Differential EquationsMar 10 2007We present some results on the existence and nonexistence of centers for polynomial first order ordinary differential equations with complex coefficients. In particular, we show that binomial differential equations without linear terms do not complex ... More
Elastomeric focusing enables application of hydraulic principles to solid materials in order to create micromechanical actuators with giant displacementsNov 19 2017A continuing challenge in material science is how to create active materials in which shape changes or displacements can be generated electrically or thermally. Here we borrow principles from hydraulics, in particular that confined geometries can be used ... More
Highly Nonlinear Ising Model and Social SegregationJun 28 2011The usual interaction energy of the random field Ising model in statistical physics is modified by complementing the random field by added to the energy of the usual Ising model a nonlinear term S^n were S is the sum of the neighbor spins, and n=0,1,3,5,7,9,11. ... More
Interacting agegraphic quintessence dark energy in non-flat universeSep 02 2009Mar 30 2010We suggest a correspondence between interacting agegraphic dark energy models and the quintessence scalar field in a non-flat universe. We demonstrate that the agegraphic evolution of the universe can be described completely by a single quintessence scalar ... More
On Chebyshev polynomials and torus knotsDec 23 2009Jan 14 2010In this work we demonstrate that the q-numbers and their two-parameter generalization, the q,p-numbers, can be used to obtain some polynomial invariants for torus knots and links. First, we show that the q-numbers, which are closely connected with the ... More
A practical gauge invariant regularization of the SO(10) grand unified modelDec 15 2000It is shown that a simple modification of the dimensional regularization allows to compute in a consistent and gauge invariant way any diagram with less than four loops in the SO(10) unified model. The method applies also to the Standard Model generated ... More
Dynamics of the Flows Accreting onto a Magnetized Neutron StarDec 14 2004Non-stationary column accretion onto a surface of a magnetized neutron star is studied with a numerical code based on modified first-order Godunov method with splitting. Formation and evolution of shocks in the column is modeled for accretion rates ranging ... More
The Absence of the Fractional Quantum Hall Effect at High Landau LevelsFeb 25 1996We compare the energies of the Laughlin liquid and a charge density wave in a weak magnetic field for the upper Landau level filling factors $\nu_N = 1/3$ and $1/5$. The charge density wave period has been optimized and was found to be $\simeq 3R_c$, ... More
New Superconducting RbFe2As2: A First-principles InvestigationNov 12 2009RbFe2As2 has recently been reported to be a bulk superconductor with Tc = 2.6 K in the undoped state, in contrast to undoped BaFe2As2 with a magnetic ground state. We present here the results of the first-principles calculations of the structural, elastic ... More
Electron States in a Staircase Infinitely Deep Well in a Magnetic FieldSep 20 1999The electron states in a size-quantaized coated semiconductor wire in a uniform magnetic field applied parallel to the wire axis is considered. The wave functions are found and the equation for determination of energy eigenvalues depending both on magnetic ... More
Classical limit of the Knizhnik-Zamolodchikov-Bernard equations as hierarchy of isomonodromic deformations. Free fields approachSep 29 1997Mar 06 1998We investigate the classical limit of the Knizhnik-Zamolodchikov-Bernard equations, considered as a system of non-stationar Schr\"{o}odinger equations on singular curves, where times are the moduli of curves. It has a form of reduced non-autonomous hamiltonian ... More
Propagating two-dimensional magnetic dropletsNov 09 2011Jan 18 2012Propagating, solitary magnetic wave solutions of the Landau-Lifshitz equation with uniaxial, easy-axis anisotropy in thin (two-dimensional) magnetic films are investigated. These localized, nontopological wave structures, parametrized by their precessional ... More
Effects of polydispersity on the phase coexistence diagrams in multiblock copolymers with Laser block length distributionJul 16 2002Phase behavior of AB-multiblock copolymer melts which consists of chains with Laser distribution of A and B blocks have been investigated in the framework of the mean-field theory, where the polydispersity of copolymer is a function of two parameters ... More
Mesoscopic fluctuations of the supercurrent in diffusive Josephson junctionsApr 25 2007We study mesoscopic fluctuations and weak localization correction to the supercurrent in Josephson junctions with coherent diffusive electron dynamics in the normal part. Two kinds of junctions are considered: a chaotic dot coupled to superconductors ... More
Quantifying entanglement of two relativistic particles via decomposable optimal entanglement witnessesNov 12 2009The study of Entanglement of Formation of a mixed state of a bipartite system in high-dimensional Hilbert space is not easy in general. So, we focus on determining the amount of entanglement for a bipartite mixed state based on the concept of decomposable ... More
Local-global mode interaction in stringer-stiffened platesJun 07 2014Sep 19 2014A recently developed nonlinear analytical model for axially loaded thin-walled stringer-stiffened plates based on variational principles is extended to include local buckling of the main plate. Interaction between the weakly stable global buckling mode ... More
A Study on Dual Mannheim Partner CurvesJan 26 2010Mannheim partner curves are studied by Liu and Wang [1,2]. Orbay and others extended the theory of the Mannheim curves to the ruled surface in Euclidean 3-space[3]. We obtain the relationships between the curvatures and the torsions of the dual Mannheim ... More
On certain semigroups of partial contractions of a finite chainMar 07 2018Let $[n]=\{1,2,\ldots,n\}$ be a finite chain and let $\mathcal{P}_{n}$ be the semigroup of partial transformations on $[n]$. Let $\mathcal{CP}_{n}=\{\alpha\in \mathcal{P}_{n}: (for ~all~x,y\in Dom~\alpha)~|x\alpha-y\alpha|\leq|x-y|\}$ be the subsemigroup ... More
Quantum Corrections to the Entropy for Higher Spin Fields in Hyperbolic SpaceDec 20 1994Dec 26 1994We calculate the one-loop corrections to the free energy and to the entropy for fields with arbitrary spins in the space $S^1\otimes H^N$. For conformally invariant fields by means of a conformal transformation of the metric the results are valid in Rindler ... More
On higher spin partition functionsMar 27 2015Jun 05 2015We observe that the partition function of the set of all free massless higher spins s=0,1,2,3,... in flat space is equal to one: the ghost determinants cancel against the "physical" ones or, equivalently, the (regularized) total number of degrees of freedom ... More
Wilson loops T-dual to Short StringsDec 19 2012Jan 21 2013We show that closed string solutions in the bulk of AdS space are related by T-duality to solutions representing an open string ending at the boundary of AdS. By combining the limit in which a closed string becomes small with a large boost, we find that ... More
Exact solutions for U(1) globally invariant membranesMar 29 2009Aug 30 2009The exact solvability problem of the nonlinear equations describing the U(1) invariant membranes is studied and the general solution for the static membrane in D=2N+1-dimensional Minkowski space-time, including M-theory case D=11, is obtained. The time-dependent ... More
Phonon-assisted decoherence in coupled quantum dotsFeb 19 2007We analyse various phonon-assisted mechanisms which contribute to the decoherence of excitonic qubits in quantum dot systems coupled by the F\"orster-type transfer process. We show the significant loss of coherence accompanied by dissipation due to charge ... More
Pohlmeyer reduction of AdS_5 x S^5 superstring sigma modelNov 01 2007Jan 07 2008Motivated by a desire to find a useful 2d Lorentz-invariant reformulation of the AdS_5 x S^5 superstring world-sheet theory in terms of physical degrees of freedom we construct the Pohlmeyer-reduced version of the corresponding sigma model. The Pohlmeyer ... More
Desynchronization and Speedup in an Asynchronous Conservative Parallel Update ProtocolSep 16 2004In a state-update protocol for a system of $L$ asynchronous parallel processes that communicate only with nearest neighbors, global desynchronization in operation times can be deduced from kinetic roughening of the corresponding virtual-time horizon (VTH). ... More
Discrete-Event Analytic Technique for Surface Growth ProblemsNov 02 2003Feb 23 2004We introduce an approach for calculating non-universal properties of rough surfaces. The technique uses concepts of distinct surface-configuration classes, defined by the surface growth rule. The key idea is a mapping between discrete events that take ... More
The spatial Λ-Fleming-Viot process on a large torus: Genealogies in the presence of recombinationJun 20 2011Nov 27 2012We extend the spatial $\Lambda$-Fleming-Viot process introduced in [Electron. J. Probab. 15 (2010) 162-216] to incorporate recombination. The process models allele frequencies in a population which is distributed over the two-dimensional torus $\mathbb{T}(L)$ ... More
Polarimetry toward the IRAS Vela Shell. II. Extinction and Magnetic FieldsFeb 21 2007We explore correlations between visual extinction and polarization along the western side of the IRAS Vela Shell using a published polarimetric catalog of several hundreds of objects. Our extinction maps along this ionization front (I-front) find evidence ... More
Impurity systems fluctuating between two magnetic configurations: candidates for non Fermi-liquid behaviorApr 29 1993The appropriate generalization of the isotropic impurity Anderson model for valence fluctuations between two magnetic multiplets $l^n$ and $l^{n+1}$ is solved in the strong-coupling limit of Wilson's renormalization group for $l\leq$ 3. Except in the ... More
Detection of gravitational waves from inspiraling compact binaries using non-restricted post-Newtonian approximationsMay 16 2000The set up of matched filters for the detection of gravitational waves from in-spiraling compact binaries is usually carried out using the restricted post-Newtonian approximation: the filter phase is modelled including post-Newtonian corrections, whereas ... More
LISA observations of massive black holes binaries using post-Newtonian wave-formsMay 16 2000We consider LISA observations of in-spiral signals emitted by massive black hole binary systems in circular orbit and with negligible spins. We study the accuracy with which the source parameters can be extracted from the data stream. We show that the ... More
Asymptotic analysis of average case approximation complexity of additive random fieldsOct 30 2017We study approximation properties of sequences of centered additive random fields $Y_d$, $d\in\mathbb{N}$. The average case approximation complexity $n^{Y_d}(\varepsilon)$ is defined as the minimal number of evaluations of arbitrary linear functionals ... More
Field dependence of the vortex-core sizes in dirty two-band superconductorsMar 29 2019We study the structure of Abrikosov vortices in two-band superconductors for different external magnetic fields and different parameters of the bands. The vortex core size determined by the coherence lengths are found to have qualitatively different behaviour ... More
Polaritonic linear dynamic in Keldysh formalismSep 02 2016We study the dynamic of polaritons in the Keldysh functional formalism. Dissipation is considered through the coupling of the exciton and photon fields to two independent photonic and excitonic baths. As such, this theory allows to describe more intricate ... More
New CCD photometric observation of the W-UMa eclipsing binary system 1swasp j160156.04+202821.6Feb 23 2014New BVRI light curves of the eclipsing binary system 1SWASP J160156.04+202821.6 have been obtained with the 1.88-m telescope of Kottamia Astronomical Observatory (KAO), Egypt on June, 2013. New twenty times of minima of the system J1601 and new ephemeris ... More
Generalized Kinetic Theory of Electrons and Phonons: Models, Equilibrium, StabilityMar 18 2003In the present paper our aim is to introduce some models for the generalization of the kinetic theory of electrons and phonons (KTEP), as well as to study equilibrium solutions and their stability for the generalized KTEP (GKTEP) equations. We consider ... More
Emergent universal critical behavior of the 2D $N$-color Ashkin-Teller model in the presence of correlated disorderFeb 14 2017Mar 31 2017We study the critical behavior of the 2D $N$-color Ashkin-Teller model in the presence of random bond disorder whose correlations decays with the distance $r$ as a power-law $r^{-a}$. We consider the case when the spins of different colors sitting at ... More
An Elliptic Curve-based Signcryption Scheme with Forward SecrecyMay 11 2010Mar 19 2012An elliptic curve-based signcryption scheme is introduced in this paper that effectively combines the functionalities of digital signature and encryption, and decreases the computational costs and communication overheads in comparison with the traditional ... More
LPKI - A Lightweight Public Key Infrastructure for the Mobile EnvironmentsFeb 17 2010Mar 16 2012The non-repudiation as an essential requirement of many applications can be provided by the asymmetric key model. With the evolution of new applications such as mobile commerce, it is essential to provide secure and efficient solutions for the mobile ... More
Recurrence relations for polynomial sequences via Riordan matricesApr 17 2009Jul 02 2009We give recurrence relations for any family of generalized Appell polynomials unifying so some known recurrences of many classical sequences of polynomials. Our main tool to get our goal is the Riordan group. We use the product of Riordan matrices to ... More
The large N theory exactly reveals the quantum Hall effect and theta-renormalizationDec 30 2000We revisit the $\theta$ dependence in $CP^{N-1}$ model with large $N$. We study the consequences of a recently discovered new ingredient of the instanton vacuum, i.e. the massless chiral edge excitations. Contrary to the previous believes, our results ... More
On the Canonical Form of a Pair of Compatible AntibracketsAug 14 1997In the triplectic quantization of general gauge theories, we prove a `triplectic' analogue of the Darboux theorem: we show that the doublet of compatible antibrackets can be brought to a weakly-canonical form provided the general triplectic axioms of ... More
Can mass loss and overshooting prevent the excitation of g-modes in blue supergiants?Apr 29 2009Thanks to their past history on the main sequence phase, supergiant massive stars develop a convective shell around the helium core. This intermediate convective zone (ICZ) plays an essential role in governing which g-modes are excited. Indeed a strong ... More
Electromagnetic interactions of mesons induced by the axial-vector -- pseudoscalar mixingsJul 20 2018It is shown that the diagonalization of the axial-vector -- pseudoscalar transitions in the effective meson Lagrangian in presence of electromagnetic interactions leads to a deviation from the vector meson dominance picture which usually arises in the ... More
Stability beyond the neutron drip-line near the third peak of the r-process nucleosynthesisJan 12 2011Jun 30 2011We have investigated the nuclear shell effects at N=126 in the region of the third peak of the r-process nucleosynthesis within the framework of the relativistic mean-field theory using the Lagrangian model NL-SV1 with the vector self-coupling of omega-meson. ... More
Thermodynamics of Charged Brans-Dicke AdS Black HolesApr 11 2009Aug 01 2009It is well-known that in four dimensions, black hole solution of the Brans-Dikce-Maxwell equations is just the Reissner-Nordstrom solution with a constant scalar field. However, in $n\geq4$ dimensions, the solution is not yet the $(n+1)$-dimensional Reissner-Nordstrom ... More
Electric discharge contour dynamics model: the effects of curvature and finite conductivityMar 02 2011Jul 11 2011In this paper we present the complete derivation of the effective contour model for electrical discharges which appears as the asymptotic limit of the minimal streamer model for the propagation of electric discharges, when the electron diffusion is small. ... More
On certain semigroups of full contractions of a finite chainApr 25 2018Let $[n]=\{1,2,\ldots,n\}$ be a finite chain and let $\mathcal{T}_{n}$ be the semigroup of full transformations on $[n]$. Let $\mathcal{CT}_{n}=\{\alpha\in \mathcal{T}_{n}: (for ~all~x,y\in [n])~\left|x\alpha-y\alpha\right|\leq\left|x-y\right|\}$, then ... More
Completeness of the Coulomb scattering wave functionsFeb 01 2006Completeness of the eigenfunctions of a self-adjoint Hamiltonian, which is the basic ingredient of quantum mechanics, plays an important role in nuclear reaction and nuclear structure theory. However, until now, there was no a formal proof of the completeness ... More
Radio structures of the nuclei of nearby Seyfert galaxies and the nature of the missing diffuse emissionNov 04 2009We present archival high spatial resolution VLA and VLBA data of the nuclei of seven of the nearest and brightest Seyfert galaxies in the Southern Hemisphere. At VLA resolution (~0.1 arcsec), the nucleus of the Seyfert galaxies is unresolved, with the ... More
Evidence of parsec-scale jets in Low-luminosity Active Galactic NucleiMar 26 2014Apr 28 2014The nuclear radio emission of low-luminosity active galactic nuclei (LLAGN) is often associated with unresolved cores. In this paper we show that most LLAGN present extended jet radio emission when observed with sufficient angular resolution and sensitivity. ... More
Quasipatterns in parametrically forced systemsOct 26 2006We examine two mechanisms that have been put forward to explain the selection of quasipatterns in single and multi-frequency forced Faraday wave experiments. Both mechanisms can be used to generate stable quasipatterns in a parametrically forced partial ... More
Relativistic entanglement in single-particle quantum states using Non-Linear entanglement witnessesApr 18 2012May 02 2012In this study, the spin-momentum correlation of one massive spin-1/2 and spin-1 particle states, which are made based on projection of a relativistic spin operator into timelike direction is investigated. It is shown that by using Non-Linear entanglement ... More
Generalized Analysis of Elastic Wave Dispersion Asymmetries in Moving Periodic MediaFeb 23 2018Mar 05 2018This work presents a generalized physical interpretation of unconventional dispersion asymmetries associated moving elastic solids. By shifting the notion from systems with time-variant material fields to physically traveling materials, the newly adopted ... More
A multiplicity result for double singularly perturbed elliptic systemsJan 19 2015We show that the number of low energy solutions of a double singularly perturbed Schroedinger Maxwell system type on a smooth 3 dimensional manifold (M,g) depends on the topological properties of the manifold. The result is obtained via Lusternik Schnirelmann ... More
Spin observables in pion photoproduction from a unitary and causal effective field theoryDec 29 2010Jan 04 2011Pion photoproduction is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge ... More
Best separable approximation with semi-definite programming methodJun 08 2006The present methods for obtaining the optimal Lewenestein- Sanpera decomposition of a mixed state are difficult to handle analytically. We provide a simple analytical expression for the optimal Lewenstein-Sanpera decomposition by using semidefinite programming. ... More
Decays of Supersymmetric Particles: the program SUSY-HIT (SUspect-SdecaY-Hdecay-InTerface)Sep 28 2006We present the program package SUSY-HIT for the computation of supersymmetric particle decays within the framework of the Minimal Supersymmetric extension of the Standard Model. The code is based on two existing programs HDECAY and SDECAY for the calculation ... More
Quantum Coulomb gap in low dimensionsMay 23 2012We study the single-particle density of states of one-dimensional and two-dimensional quantum disordered systems with long-range interactions. We consider a $1/\sqrt{r}$ interaction in one dimension and a Coulomb interaction in two dimensions, which produce ... More
Parton densities with the quark linear potential in the statistical approachMar 25 2014The statistical approach is used to calculate the parton distribution functions (PDFs) of the nucleon. At first it is assumed that the partons are free particles and the light-front kinematic variables are employed to extract the Bjorken $x$-dependence ... More
Minimizing Strong Telluric Absorption in Near Infra-red Stellar SpectraOct 21 2003We have obtained high resolution spectra (R = 25000) of an A star over varying airmass to determine the effectiveness of telluric removal in the limit of high signal to noise. The near infra-red line HeI at 2.058 microns, which is a sensitive indicator ... More
Higher spins in AdS_5 at one loop: vacuum energy, boundary conformal anomalies and AdS/CFTOct 13 2014Nov 18 2014We consider general-symmetry higher spin fields in AdS_5 and derive expressions for their one-loop corrections to vacuum energy E and the associated 4d boundary conformal anomaly a-coefficient. We a propose a similar expression for the second conformal ... More
Nonuniversal effects in mixing correlated-growth processes with randomness: Interplay between bulk morphology and surface rougheningJan 24 2015To construct continuum stochastic growth equations for competitive nonequilibrium surface-growth processes of the type RD+X that mixes random deposition (RD) with a correlated-growth process X, we use a simplex decomposition of the height field. A distinction ... More
Diamond-Like Carbon film from Liquid Gas on Metallic SubstratesJan 05 1998Liquid gas was used to produce DLC films on Cu, Al and steel substrates by DC plasma technique. The absorption in IR reflectance indicates, grown films are DLC. By deconvolution of room temperature UV-visible spectra of the films grown at 50 mtorr and ... More
Charged string solutions with dilaton and modulus fieldsJul 19 1993Nov 19 1993We find charged, abelian, spherically symmetric solutions (in flat space-time) corresponding to the effective action of $D=4$ heterotic string theory with scale-dependent dilaton $\p$ and modulus $\vp$ fields. We take into account perturbative (genus-one), ... More
Quantum quench dynamics of the sine-Gordon model in some solvable limitsMar 26 2010In connection with the the thermalization problem in isolated quantum systems, we investigate the dynamics following a quantum quench of the sine-Gordon model in the Luther-Emery and the semiclassical limits. We consider the quench from the gapped to ... More
Cecotti-Fendley-Intriligator-Vafa Index in a BoxNov 30 2011The Cecotti-Fendley-Intriligator-Vafa (CFIV) index in two-dimensional ${\mathcal N} =(2,2)$ models is revisited. We address the problem of "elementary" (nontopological) excitations over a kink solution, in the one-kink sector (using the Wess-Zumino or ... More
Probe of electromagnetic moments of the tau lepton in gamma-gamma collisions at the CLICJun 24 2013Feb 09 2014We have investigated the electromagnetic moments of the tau lepton in $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-}\rightarrow e^{+}\tau \bar{\tau}e^{-}$ process at the CLIC. We have obtained 95% confidence level bounds on the anomalous magnetic ... More
$S$-Functions, Spectral Functions of Hyperbolic Geometry, and Vertex Operators with Applications to Structure for Weyl and Orthogonal Group InvariantsFeb 22 2016In this paper we analyze the quantum homological invariants (the Poincar\'e polynomials of the $\mathfrak{sl}_N$ link homology). In the case when the dimensions of homologies of appropriate topological spaces are precisely known, the procedure of the ... More