Results for "Premkumar T. Devanbu"

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Are My Invariants Valid? A Learning ApproachMar 14 2019Mar 15 2019Ensuring that a program operates correctly is a difficult task in large, complex systems. Enshrining invariants -- desired properties of correct execution -- in code or comments can support maintainability and help sustain correctness. Tools that can ... More
Converging Work-Talk Patterns in Online Task-Oriented CommunitiesApr 23 2014Much of what we do is accomplished by working collaboratively with others, and a large portion of our lives are spent working and talking; the patterns embodied in the alternation of working and talking can provide much useful insight into task-oriented ... More
OntoCat: Automatically categorizing knowledge in API DocumentationJul 26 2016Most application development happens in the context of complex APIs; reference documentation for APIs has grown tremendously in variety, complexity, and volume, and can be difficult to navigate. There is a growing need to develop well-organized ways to ... More
Are My Invariants Valid? A Learning ApproachMar 14 2019Ensuring that a program operates correctly is a difficult task in large, complex systems. Enshrining invariants -- desired properties of correct execution -- in code or comments can support maintainability and help sustain correctness. Tools that can ... More
Modeling and verifying a broad array of network propertiesMay 12 2008Mar 26 2009Motivated by widely observed examples in nature, society and software, where groups of already related nodes arrive together and attach to an existing network, we consider network growth via sequential attachment of linked node groups, or graphlets. We ... More
Whom Are You Going to Call?: Determinants of @-Mentions in GitHub DiscussionsJun 21 2018Open Source Software (OSS) project success relies on crowd contributions. When an issue arises in pull-request based systems, @-mentions are used to call on people to task; previous studies have shown that @-mentions in discussions are associated with ... More
Initial and Eventual Software Quality Relating to Continuous Integration in GitHubJun 02 2016The constant demand for new features and bug fixes are forcing software projects to shorten cycles and deliver updates ever faster, while sustaining software quality. The availability of inexpensive, virtualized, cloud-computing has helped shorten schedules, ... More
Studying the Difference Between Natural and Programming Language CorporaJun 06 2018Code corpora, as observed in large software systems, are now known to be far more repetitive and predictable than natural language corpora. But why? Does the difference simply arise from the syntactic limitations of programming languages? Or does it arise ... More
On the "Naturalness" of Buggy CodeJun 03 2015Sep 10 2015Real software, the kind working programmers produce by the kLOC to solve real-world problems, tends to be "natural", like speech or natural language; it tends to be highly repetitive and predictable. Researchers have captured this naturalness of software ... More
Unsupervised Adversarial InvarianceSep 26 2018Data representations that contain all the information about target variables but are invariant to nuisance factors benefit supervised learning algorithms by preventing them from learning associations between these factors and the targets, thus reducing ... More
BugSwarm: Mining and Continuously Growing a Dataset of Reproducible Failures and FixesMar 15 2019Fault-detection, localization, and repair methods are vital to software quality; but it is difficult to evaluate their generality, applicability, and current effectiveness. Large, diverse, realistic datasets of durably-reproducible faults and fixes are ... More
CapsuleGAN: Generative Adversarial Capsule NetworkFeb 17 2018Oct 02 2018We present Generative Adversarial Capsule Network (CapsuleGAN), a framework that uses capsule networks (CapsNets) instead of the standard convolutional neural networks (CNNs) as discriminators within the generative adversarial network (GAN) setting, while ... More
QATM: Quality-Aware Template Matching For Deep LearningMar 18 2019Finding a template in a search image is one of the core problems many computer vision, such as semantic image semantic, image-to-GPS verification \etc. We propose a novel quality-aware template matching method, QATM, which is not only used as a standalone ... More
Bidirectional Conditional Generative Adversarial NetworksNov 20 2017Nov 03 2018Conditional Generative Adversarial Networks (cGANs) are generative models that can produce data samples ($x$) conditioned on both latent variables ($z$) and known auxiliary information ($c$). We propose the Bidirectional cGAN (BiCoGAN), which effectively ... More
Optimum Sleep-Wake Scheduling of Sensors for Quickest Event Detection in Small Extent Wireless Sensor NetworksMay 30 2011We consider the problem of quickest event detection with sleep-wake scheduling in small extent wireless sensor networks in which, at each time slot, each sensor node in the awake state observes a sample and communicates the information to the fusion centre. ... More
Linking density functional and mode coupling models for supercooled liquidsDec 23 2015We compare predictions from two familiar models of the metastable supercooled liquid respectively constructed with thermodynamic and dynamic approach. In the so called density functional theory (DFT) the free energy $F[\rho]$ of the liquid is a functional ... More
Localization, disorder and boson peak in an amorphous solidMar 17 2013We demonstrate using the classical density functional theory (DFT) model that an intermediate degree of mass localization in the amorphous state is essential for producing the boson peak. The localization length $\ell$ is identified from the width of ... More
Fragility index of a simple liquid from structural inputsDec 25 2015We make a first principle calculation of the fragility index $m$ of a simple liquid using the structure of the supercooled liquid as an input. Using the density functional theory (DFT) of classical liquids, the configurational entropy ${\cal S}_c$ is ... More
Utility Optimal Coding for Packet Transmission over Wireless Networks - Part II: Networks of Packet Erasure ChannelsJul 10 2011We define a class of multi--hop erasure networks that approximates a wireless multi--hop network. The network carries unicast flows for multiple users, and each information packet within a flow is required to be decoded at the flow destination within ... More
Proportional Fair Coding for Wireless Mesh NetworksJan 18 2012We consider multi--hop wireless networks carrying unicast flows for multiple users. Each flow has a specified delay deadline, and the lossy wireless links are modelled as binary symmetric channels (BSCs). Since transmission time, also called airtime, ... More
Distributed Detection/Isolation Procedures for Quickest Event Detection in Large Extent Wireless Sensor NetworksMay 30 2011Jul 18 2011We study a problem of distributed detection of a stationary point event in a large extent wireless sensor network ($\wsn$), where the event influences the observations of the sensors only in the vicinity of where it occurs. An event occurs at an unknown ... More
Utility Optimal Coding for Packet Transmission over Wireless Networks - Part I: Networks of Binary Symmetric ChannelsJul 10 2011We consider multi--hop networks comprising Binary Symmetric Channels ($\mathsf{BSC}$s). The network carries unicast flows for multiple users. The utility of the network is the sum of the utilities of the flows, where the utility of each flow is a concave ... More
The yielding transition in amorphous solids under oscillatory shear deformationDec 08 2016Amorphous solids are ubiquitous among natural and man-made materials. Often used as structural materials for their attractive mechanical properties, their utility depends critically on their response to applied stresses. Processes underlying such mechanical ... More
Delay Optimal Event Detection on Ad Hoc Wireless Sensor NetworksMay 30 2011We consider a small extent sensor network for event detection, in which nodes take samples periodically and then contend over a {\em random access network} to transmit their measurement packets to the fusion center. We consider two procedures at the fusion ... More
Distributed Computation of the Conditional PCRLB for Quantized Decentralized Particle FiltersJul 20 2013The conditional posterior Cramer-Rao lower bound (PCRLB) is an effective sensor resource management criteria for large, geographically distributed sensor networks. Existing algorithms for distributed computation of the PCRLB (dPCRLB) are based on raw ... More
AIRD: Adversarial Learning Framework for Image Repurposing DetectionMar 02 2019Mar 06 2019Image repurposing is a commonly used method for spreading misinformation on social media and online forums, which involves publishing untampered images with modified metadata to create rumors and further propaganda. While manual verification is possible, ... More
Blockwise SURE Shrinkage for Non-Local MeansMay 18 2013In this letter, we investigate the shrinkage problem for the non-local means (NLM) image denoising. In particular, we derive the closed-form of the optimal blockwise shrinkage for NLM that minimizes the Stein's unbiased risk estimator (SURE). We also ... More
Probabilistic Non-Local MeansFeb 23 2013In this paper, we propose a so-called probabilistic non-local means (PNLM) method for image denoising. Our main contributions are: 1) we point out defects of the weight function used in the classic NLM; 2) we successfully derive all theoretical statistics ... More
Learning Document Image Binarization from DataMay 04 2015In this paper we present a fully trainable binarization solution for degraded document images. Unlike previous attempts that often used simple features with a series of pre- and post-processing, our solution encodes all heuristics about whether or not ... More
Quantum transitions induced by the third cumulant of current fluctuationsJun 23 2005Oct 14 2005We investigate the transitions induced by external current fluctuations on a small probe quantum system. The rates for the transitions between the energy states are calculated using the real-time Keldysh formalism for the density matrix evolution. We ... More
Orthogonal polynomials in several non-commuting variables. IIDec 29 2004In this paper we continue to investigate a certain class of Hankel-like positive definite kernels using their associated orthogonal polynomials. The main result of this paper is about the structure of this kind of kernels.
Supersymmetric Grand Unification Model with the Orbifold Symmetry Breaking in the Six Dimensional SupergravityAug 19 2001We construct supersymmetric (SUSY) grand unification (GUT) models in the six dimensional space-time where the GUT symmetry is broken down to the standard-model gauge group by a simple orbifolding T^2/Z_4 or T^2/Z_6 and a pair of massless Higgs doublets ... More
Semi-Simple Unification on T^6/Z_12 Orientifold in the Type IIB SupergravityAug 06 2001The semi-simple unification model based on SU(5)_GUT \times U(3)_H gauge group is an interesting extension of the minimal SU(5)_GUT grand unification theory (GUT), since it solves the two serious problems in the standard GUT: the triplet-doublet splitting ... More
Small Violation of Universal Yukawa Coupling and Neutrino Large MixingSep 15 2000We assume the universal Yukawa coupling (democratic mass matrix) with small violations for quarks, charged leptons and neutrinos masses. We could reproduce the mass hierarchy for quark masses and V_{CKM} matrix elements precisely. We adopt the see-saw ... More
Dynamics of a tagged particle in the asymmetric exclusion process with the step initial conditionFeb 02 2007Jul 06 2007The one-dimensional totally asymmetric simple exclusion process (TASEP) is considered. We study the time evolution property of a tagged particle in TASEP with the step-type initial condition. Calculated is the multi-time joint distribution function of ... More
Polynuclear growth model, GOE$^2$ and random matrix with deterministic sourceNov 17 2004We present a random matrix interpretation of the distribution functions which have appeared in the study of the one-dimensional polynuclear growth (PNG) model with external sources. It is shown that the distribution, GOE$^2$, which is defined as the square ... More
Fluctuations of a one-dimensional polynuclear growth model in a half spaceJul 01 2003We consider the multi-point equal time height fluctuations of a one-dimensional polynuclear growth model in a half space. For special values of the nucleation rate at the origin, the multi-layer version of the model is reduced to a determinantal process, ... More
Quark beta decay in an inhomogeneous chiral phase and cooling of hybrid starsSep 28 2012We discuss the cooling of hybrid stars by considering the neutrino emission from quark matter. As a current topic the appearance of various inhomogeneous chiral phases have been studied near the chiral transition. Here we consider the dual-chiral-density-wave ... More
Streda formula for the Hofstadter-Wilson-Dirac model in two and four dimensionsSep 09 2016Nov 29 2016We rederive the spectral asymmetry of the Wilson-Dirac model in external fields, paying attention to the Chern number due to the Berry connection. We interpret the smooth part of the spectral asymmetry as the Streda formula that is originally derived ... More
Intelligent Unmanned Explorer for Deep Space ExplorationApr 30 2008asteroids or comets have received remarkable attention in the world. In small body explorations, especially, detailed in-situ surface exploration by tiny rover is one of effective and fruitful means and is expected to make strong contributions towards ... More
Transport Coefficients of Non-Newtonian Fluid and Causal Dissipative HydrodynamicsJun 23 2008Oct 20 2008A new formula to calculate the transport coefficients of the causal dissipative hydrodynamics is derived by using the projection operator method (Mori-Zwanzig formalism) in [T. Koide, Phys. Rev. E75, 060103(R) (2007)]. This is an extension of the Green-Kubo-Nakano ... More
Variational Principle of Hydrodynamics and Quantization by Stochastic ProcessDec 19 2014Jan 05 2015The well-known hydrodynamical representation of the Schr\"{o}dinger equation is reformulated by extending the idea of Nelson-Yasue's stochastic variational method. The fluid flow is composed by the two stochastic processes from the past and the future, ... More
Thermodynamic Laws and Equipartition Theorem in Relativistic Brownian MotionFeb 16 2011Apr 27 2011We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation ... More
Searching for g modes: Part II. Unconfirmed g-mode detection in the power spectrum of the time series of round-trip travel timeMar 09 2019The recent claimed detection of g modes was obtained from the analysis of the power spectrum of the time series of round-trip travel time of p modes. The goal of this paper is to reproduce these results on which the claims are based for confirming or ... More
Lattice QCD Study of the Pentaquark BaryonsOct 19 2004Oct 25 2004We study the spin $\frac12$ hadronic state in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance. Simulations are carried out on $8^3\times 24$, $10^3\times 24$, $12^3\times 24$ and $16^3\times 24$ lattices at $\beta$=5.7 at the ... More
Momentum-space structure of surface states in a topological semimetal with a nexus point of Dirac linesApr 21 2016Jun 27 2016Three-dimensional topological semimetals come in different variants, either containing Weyl points or Dirac lines. Here we describe a more complicated momentum-space topological defect where several separate Dirac lines connect with each other, forming ... More
Lattice QCD study of $g_A^{N^*N^*}$ with two flavors of dynamical quarksNov 13 2007We report the first lattice QCD result of the axial charge of N(1535), $g_A^{N^*N^*}$. The measurement is performed with two flavors of dynamical quarks employing the renormalization-group improved gauge action at $\beta$=1.95 and the mean-field improved ... More
Classical and Quantum Gravity in 1+1 Dimensions, Part II: The Universal CoveringsNov 30 1995Apr 26 1996A set of simple rules for constructing the maximal (e.g. analytic) extensions for any metric with a Killing field in an (effectively) two-dimensional spacetime is formulated. The application of these rules is extremely straightforward, as is demonstrated ... More
Pre-critical Chiral Fluctuations in Nuclear Medium -- precursors of chiral restoration at $ρ_{B}\not=0 --Feb 10 1999Feb 26 1999It is shown that an enhancement in the spectral function near 2$m_{\pi}$ threshold in the I=J=0 channel is a good signal of the partial restoration of chiral symmetry in nuclear medium. Several experiments are discussed to detect the enhancement, which ... More
Including stereoscopic information in the reconstruction of coronal magnetic fieldsJan 21 2008Jan 23 2008We present a method to include stereoscopic information about the three dimensional structure of flux tubes into the reconstruction of the coronal magnetic field. Due to the low plasma beta in the corona we can assume a force free magnetic field, with ... More
A Z$_2$ index of Dirac operator with time reversal symmetryMay 22 2009With time reversal symmetry a Dirac operator has vanishing index and Chern number. We show that we can nevertheless define a nontrivial Z$_2$ index as well as a corresponding topological invariant given by gauge field, which implies that such a Dirac ... More
Quantization of non-Abelian Berry phase for time reversal invariant systemsMar 18 2009We present a quantized non-Abelian Berry phase for time reversal invariant systems such as quantum spin Hall effect. Ordinary Berry phase is defined by an integral of Berry's gauge potential along a loop (an integral of the Chern-Simons one-form), whereas ... More
Thermal Field Theory and Infinite StatisticsJun 17 1992Oct 28 1992We construct a quantum thermal field theory for scalar particles in the case of infinite statistics. The extension is provided by working out the Fock space realization of a "quantum algebra", and by identifying the hamiltonian as the energy operator. ... More
Stops in R-parity Breaking Model for High-$Q^2$ Events at HERAApr 03 1997We investigate an event excess in the reaction $e^+p \to e^+ X$ with large $x$ and high $Q^2$ observed at HERA and show that the events could naturally be interpreted as a signature of the production of the scalar top quarks (stops) in a supersymmetric ... More
Stochastic Variational Method as Quantization Scheme I: Field Quantization of Complex Klein-Gordan EquationJun 28 2013Jun 24 2014Stochastic Variational Method (SVM) is the generalization of the variation method to the case with stochastic variables. In the series of papers, we investigate the applicability of SVM as an alternative field quantization scheme. Here, we discuss the ... More
Dynamical Origin of Power SpectraDec 27 2008We discuss a possible origin of Tsallis' statistics from the correlation among constituents which reduces the phase space of the system. We also show that in the system of coupled linear harmonic oscillators can exhibit a Tsallis type behavior.
Memory Effects and Transport Coefficients for Non-Newtonian FluidsDec 22 2008We discuss the roles of viscosity in relativistic fluid dynamics from the point of view of memory effects. Depending on the type of quantity to which the memory effect is applied, different terms appear in higher order corrections. We show that when the ... More
A Study of a Real-Time Operating System on the Intel-Based Vme ControllersNov 09 2001Dec 17 2001In this paper, we described the performance differences between VME-based controllers, HP743rt/HP-RT and IA-based platforms. We measured some kind of real-time benchmarks and discussed a relation of architecture dependences.
Tension Dynamics and Linear Viscoelastic Behavior of a Single Semiflexible Polymer ChainMar 12 2009We study the dynamical response of a single semiflexible polymer chain based on the theory developed by Hallatschek et al. for the wormlike-chain model. The linear viscoelastic response under oscillatory forces acting at the two chain ends is derived ... More
Asymptotic behavior for quadratic variations of non-Gaussian multiparameter Hermite random fieldsNov 11 2016Dec 21 2017Let $(Z^{q, H}_t)_{t \in [0, 1]^d}$ denote a $d$-parameter Hermite random field of order $q \geq 1$ and self-similarity parameter $H = (H_1, \ldots, H_d) \in (\frac{1}{2}, 1)^d$. This process is $H$-self-similar, has stationary increments and exhibits ... More
Stau-catalyzed Nuclear FusionJul 24 2006Oct 06 2006We point out that the stau may play a role of a catalyst for nuclear fusions if the stau is a long-lived particle as in the scenario of gravitino dark matter. In this letter, we consider d d fusion under the influence of stau where the fusion is enhanced ... More
The microscopic spectrum of the QCD Dirac operator with finite quark massesNov 10 1997Apr 30 1998We compute the microscopic spectrum of the QCD Dirac operator in the presence of dynamical fermions in the framework of random-matrix theory for the chiral Gaussian unitary ensemble. We obtain results for the microscopic spectral correlators, the microscopic ... More
The Configuration Space of Low-dimensional Yang-Mills TheoriesJan 26 1998We discuss the construction of the physical configuration space for Yang-Mills quantum mechanics and Yang-Mills theory on a cylinder. We explicitly eliminate the redundant degrees of freedom by either fixing a gauge or introducing gauge invariant variables. ... More
Relativistic generalization of Brownian MotionOct 10 2007The relativistic generalization of the Brownian motion is discussed. We show that the transformation property of the noise term is determined by requiring for the equilibrium distribution function to be Lorentz invariant, such as the J\"uttner distribution ... More
Simulation Study of Solar Plasma Eruptions Caused by Interactions between Emerging Flux and Coronal Arcade FieldsOct 01 2014We investigate the triggering mechanisms of plasma eruptions in the solar atmosphere due to interactions between emerging flux and coronal arcade fields by using two-dimensional MHD simulations. We perform parameter surveys with respect to arcade field ... More
A Global View of Kinks in 1+1 GravityJul 25 1997Following Finkelstein and Misner, kinks are non-trivial field configurations of a field theory, and different kink-numbers correspond to different disconnected components of the space of allowed field configurations for a given topology of the base manifold. ... More
Complete Classification of 1+1 Gravity SolutionsNov 25 1997A classification of the maximally extended solutions for 1+1 gravity models (comprising e.g. generalized dilaton gravity as well as models with non-trivial torsion) is presented. No restrictions are placed on the topology of the arising solutions, and ... More
The $σ$-meson and $π$-$π$ Correlation in Hot/Dense Medium: soft modes for chiral transition in QCDDec 11 2001After a brief overview of the realization of chiral symmetry in hot and/or dense medium, the implications of the existence of a light scalar-isoscalar meson (which we call $\sigma$ throughout this report) are discussed in the vacuum and in the medium. ... More
Geometric Origin of Large Lepton Mixing in a Higher Dimensional SpacetimeMay 09 2002Aug 02 2002The large mixing in the lepton sector observed in the recent neutrino-oscillation experiments strongly suggest that nature of left-handed lepton doublets is very different from that of left-handed quark doublets. This means that there is a big disparity ... More
Higher Dimensional Supersymmetry as an Origin of the Three Families for Quarks and LeptonsJan 11 2002May 09 2002In a (0,1) supersymmetric (SUSY) six-dimensional gauge theory, a gauge fermion gives rise to box anomalies. These anomalies are completely canceled by assuming a vector multiplet of (1,1) SUSY. With a T^2/Z_3 orbifold compactification of the extra two ... More
N = 2 Supersymmetry in a Hybrid Inflation ModelNov 30 2000The slow roll inflation requires an extremely flat inflaton potential. The supersymmetry (SUSY) is not only motivated from the gauge hierarchy problem, but also from stabilizing that flatness of the inflaton potential against radiative corrections. However, ... More
Polarized light flavor sea-quark asymmetry in polarized semi-inclusive processesMay 11 1999Oct 08 1999We propose new formulas for extracting a difference of the polarized light sea-quark density, $\Delta\bar d(x)-\Delta\bar u(x)$, from polarized deep-inelastic semi-inclusive data. We have estimated the value of it from the present experimental data measured ... More
Non-Central Limit Theorem for Quadratic Functionals of Hermite-Driven Long Memory Moving Average ProcessesJul 27 2016Let $(Z_t^{(q, H)})_{t \geq 0}$ denote a Hermite process of order $q \geq 1$ and self-similarity parameter $H \in (\frac{1}{2}, 1)$. Consider the Hermite-driven moving average process $$X_t^{(q, H)} = \int_0^t x(t-u) dZ^{(q, H)}(u), \qquad t \geq 0.$$ ... More
Theory of Stochastic Shock Drift Acceleration for Electrons in the Shock Transition RegionMar 06 2019We propose a novel electron acceleration mechanism, which we call stochastic shock drift acceleration (SSDA), that extends the standard shock drift acceleration (SDA) for low-energy electrons at a quasi-perpendicular shock to include the effect of stochastic ... More
On the Reconstruction of Graph InvariantsMay 12 2009Jun 20 2010The reconstruction conjecture has remained open for simple undirected graphs since it was suggested in 1941 by Kelly and Ulam. In an attempt to prove the conjecture, many graph invariants have been shown to be reconstructible from the vertex-deleted deck, ... More
Charm and charmonium-like spectroscopy in B decays in BelleApr 30 2009We report measurements of the branching fractions for the decays B->D_s1(2536)+ anti-D(*), where anti-D(*) is anti-D0, D- or D*-, and study of B->X(3872) K with X(3872) decaying to D*0 anti-D0 using a sample of 657 million B anti-B pairs recorded at the ... More
Suppression of Excited-State Contributions to Stellar Reaction RatesAug 27 2013It has been shown in previous work [Phys. Rev. Lett. 101, 191101 (2008); Phys. Rev. C 80, 035801 (2009)] that a suppression of the stellar enhancement factor (SEF) occurs in some endothermic reactions at and far from stability. This effect is re-evaluated ... More
General properties of astrophysical reaction rates in explosive nucleosynthesisSep 18 2012Sep 25 2012Fundamental differences in the prediction of reaction rates with intermediate and heavy target nuclei compared to the ones with light nuclei are discussed, with special emphasis on stellar modifications of the rates. Ground and excited state contributions ... More
Evolution and Nucleosynthesis of Massive Stars and Related Nuclear UncertaintiesMay 23 2003Jun 13 2003Properties of atomic nuclei important for the prediction of astrophysical reaction rates are reviewed. In the first part, a recent simulation of evolution and nucleosynthesis of stars between 15 and 25 solar masses is presented. This study is used to ... More
Global Transmission Coefficients in Hauser-Feshbach Calculations for AstrophysicsFeb 09 1998The current status of optical potentials employed in the prediction of thermonuclear reaction rates for astrophysics in the Hauser-Feshbach formalism is discussed. Special emphasis is put on $\alpha$+nucleus potentials. A novel approach for the prediction ... More
Electroweak Strings: A Progress ReportJan 03 1993I describe the string solutions in the standard electroweak model and argue that they may be stabilized by quark, lepton or other bound states. I then reinterpret the sphaleron in terms of electroweak strings and show that it can be viewed as a loop of ... More
Finite $W$ symmetry in finite dimensional integrable systemsOct 08 1992By generalizing the Drinfeld-Sokolov reduction a large class of $W$ algebras can be constructed. We introduce 'finite' versions of these algebras by Poisson reducing Kirillov Poisson structures on simple Lie algebras. A closed and coordinate free formula ... More
Independent Sets in Classes Related to Chair/Fork-free GraphsMar 07 2016The Maximum Weight Independent Set (MWIS) problem on graphs with vertex weights asks for a set of pairwise nonadjacent vertices of maximum total weight. MWIS is known to be $NP$-complete in general, even under various restrictions. Let $S_{i,j,k}$ be ... More
Nuclear Forces from Lattice QCDSep 30 2009A method to extract nucleon-nucleon (NN) potentials from the Bethe-Salpeter amplitude in lattice QCD is presented. It is applied to the two nucleons on the lattice with quenched QCD simulations. By disentangling the mixing between the S-state and the ... More
Statistical mechanics of gravitating systems: An OverviewDec 14 2008Feb 16 2009I review several issues related to statistical description of gravitating systems in both static and expanding backgrounds. After briefly reviewing the results for the static background, I concentrate on gravitational clustering of collisionless particles ... More
A Dor - An Eclipsing Subdwarf - Brown Dwarf BinaryJan 02 2004AA Dor is an eclipsing, close, post common-envelope binary (PCEB) consisting of a sdOB primary star and an unseen cool companion with an extraordinary low mass. The evolution of this system appears enigmatic - results of a recent spectral analysis of ... More
Dynamical Correlation Functions for an Impenetrable Bose gas with open boundary conditionsDec 10 1997We study the time and temperature dependent correlation functions for an impenetrable bose gas with open boundary conditions. We derive the Fredholm determinant formulae for the correlation functions, by means of the Bethe Ansatz. In the case of time ... More
Effective theory for deformed nucleiNov 23 2010Techniques from effective field theory are applied to nuclear rotation. This approach exploits the spontaneous breaking of rotational symmetry and the separation of scale between low-energy Nambu-Goldstone rotational modes and high-energy vibrational ... More
Ground-state properties of hard core bosons in one-dimensional harmonic trapsSep 12 2002Sep 20 2002The one-particle density matrices for hard core bosons in a one-dimensional harmonic trap are computed numerically for systems with up to 160 bosons. Diagonalization of the density matrix shows that the many-body ground state is not Bose-Einstein condensed. ... More
Dirac Quantization Gravity-Yang-Mills Systems in 1+1 DimensionsMar 21 1994In two dimensions a large class of gravitational systems including, e.g., $R^2$-gravity can be quantized exactly also when coupled dynamically to a Yang-Mills theory. Some previous considerations on the quantization of pure gravity theories are improved ... More
On non-Fermi liquid quantum critical points in heavy fermion metalsApr 10 2006Heavy electron metals on the verge of a quantum phase transition to magnetism show a number of unusual non-fermi liquid properties which are poorly understood. This article discusses in a general way various theoretical aspects of this phase transition ... More
Quantum matters: Physics beyond Landau's paradigmsNov 10 2004Central to our understanding of quantum many particle physics are two ideas due to Landau. The first is the notion of the electron as a well-defined quasiparticle excitation in the many body state. The second is that of the order parameter to distinguish ... More
Properties of the random field Ising model in a transverse magnetic fieldSep 15 1997We consider the effect of a random longitudinal field on the Ising model in a transverse magnetic field. For spatial dimension $d > 2$, there is at low strength of randomness and transverse field, a phase with true long range order which is destroyed ... More
Prospects of Discovery for Supersymmetry at the TevatronJan 13 2003We summarize a discovery potential for supersymmetric particles at the \ppbar collider of Tevatron with center-of-mass energy \sqrt{s} = 2 TeV and integrated luminosity $\intlum$ = 15-30 \invfb. Any direct search is kinematically limited to below 450 ... More
The cyclic structure of unimodal permutationsJun 29 1999Unimodal (i.e. single-humped) permutations may be decomposed into a product of disjoint cycles. Some enumerative results concerning their cyclic structure -- e.g. 2/3 of them contain fixed points -- are given. We also obtain in effect a kind of combinatorial ... More
Orthogonal polynomials in several variables. IMay 31 2002In this paper we introduce and discuss some classes of orthogonal polynomials in several non-commuting variables. The emphasis is on a non-commutative version of the orthogonal polynomials on the real line. We introduce recurrence equations for these ... More
Digital Sky Surveys from the ground: Status and PerspectivesJul 28 2015Mar 21 2016I first review the status of Digital Sky Surveys. The focus will be on extragalactic surveys with an area of more than 100 sq.deg. The Sloan Digital Sky Survey is the archetype of such imaging surveys and it is its great success that has prompted great ... More
Restricted 132-alternating permutations and Chebyshev polynomialsOct 04 2002A permutation is said to be \emph{alternating} if it starts with rise and then descents and rises come in turn. In this paper we study the generating function for the number of alternating permutations on $n$ letters that avoid or contain exactly once ... More
Continued fractions, statistics, and generalized patternsOct 03 2001Oct 20 2001Recently, Babson and Steingrimsson (see \cite{BS}) introduced generalized permutations patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. Following \cite{BCS}, let $e_k\pi$ (respectively; $f_k\pi$) ... More
The nuclear energy density functional formalismSep 02 2013The present document focuses on the theoretical foundations of the nuclear energy density functional (EDF) method. As such, it does not aim at reviewing the status of the field, at covering all possible ramifications of the approach or at presenting recent ... More