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Results for "Jinhyoung Lee"

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Self-consistent non-Markovian theory of a quantum state evolution for quantum information processingMay 15 2001It is shown that the operator sum representation for non-Markovian dynamics and the Lindblad master equation in Markovian limit can be derived from a formal solution to quantum Liouville equation for a qubit system in the presence of decoherence processes ... More
Geometric extension of Clauser-Horne inequality to more qubitsMar 20 2018We propose a geometric multiparty extension of Clauser-Horne (CH) inequality. The standard CH inequality can be shown to be an implication of the fact that statistical separation between two events, $A$ and $B$, defined as $P(A\oplus B)$, where $A\oplus ... More
Necessary and sufficient condition for joint measurabilityApr 03 2019In order to analyze joint measurability of given measurements, we introduce a Hermitian operator-valued measure, called $W$-measure, such that it has marginals of positive operator-valued measures (POVMs). We prove that ${W}$-measure is a POVM {\em if ... More
Entanglement transfer from continuous variables to qubitsOct 26 2001We show that two qubits can be entangled by local interactions with an entangled two-mode continuous variable state. This is illustrated by the evolution of two two-level atoms interacting with a two-mode squeezed state. Two modes of the squeezed field ... More
Quantum plasmonic sensing: beyond the shot-noise and diffraction limitJan 02 2016May 25 2016Photonic sensors have many applications in a range of physical settings, from measuring mechanical pressure in manufacturing to detecting protein concentration in biomedical samples. A variety of sensing approaches exist, and plasmonic systems in particular ... More
Learning unknown pure quantum statesMay 17 2018We propose a learning method for estimating unknown pure quantum states. The basic idea of our method is to learn a unitary operation $\hat{U}$ that transforms a given unknown state $|\psi_\tau\rangle$ to a known fiducial state $|f\rangle$. Then, after ... More
D-outcome measurement for a nonlocality testSep 26 2003Oct 26 2004For the purpose of the nonlocality test, we propose a general correlation observable of two parties by utilizing local $d$-outcome measurements with SU($d$) transformations and classical communications. Generic symmetries of the SU($d$) transformations ... More
Operational quasiprobabilities for continuous variablesJun 12 2017Nov 01 2017We generalize the operational quasiprobability involving sequential measurements proposed by Ryu {\em et al.} [Phys. Rev. A {\bf 88}, 052123] to a continuous-variable system. The quasiprobabilities in quantum optics are incommensurate, i.e., they represent ... More
Operationally Invariant Measure of the Distance between Quantum States by Complementary MeasurementsMar 18 2003Sep 26 2003We propose an operational measure of distance of two quantum states, which conversely tells us their closeness. This is defined as a sum of differences in partial knowledge over a complete set of mutually complementary measurements for the two states. ... More
Generic Bell inequalities for multipartite arbitrary dimensional systemsMar 18 2005Jan 25 2006We present generic Bell inequalities for multipartite multi-dimensional systems. The inequalities that any local realistic theories must obey are violated by quantum mechanics for even-dimensional multipartite systems. A large set of variants are shown ... More
Nonclassicality in phase space and nonclassical correlationMay 22 2007May 15 2009Continuous variable entanglement is a manifestation of nonclassicality of quantum states. In this paper we attempt to analyze whether and under which conditions nonclassicality can be used as an entanglement criterion. We adopt the well-accepted definition ... More
Quantum information processing for a coherent superposition state via a mixed entangled coherent channelApr 18 2001Aug 10 2001An entangled two-mode coherent state is studied within the framework of $2\times 2$ dimensional Hilbert space. An entanglement concentration scheme based on joint Bell-state measurements is worked out. When the entangled coherent state is embedded in ... More
Transfer of nonclassical features in quantum teleportation via a mixed quantum channelMar 18 2000Quantum teleportation of a continuous-variable state is studied for the quantum channel of a two-mode squeezed vacuum influenced by a thermal environment. Each mode of the squeezed vacuum is assumed to undergo the same thermal influence. It is found that ... More
Entropic lower bound for distinguishability of quantum statesNov 07 2015Nov 10 2015For a system randomly prepared in a number of quantum states, we present a lower bound for the distinguishability of the quantum states, that is, the success probability of determining the states in the form of entropy. When the states are all pure, acquiring ... More
Vacuum as a less hostile environment to entanglementApr 16 2007Mar 05 2008We derive sufficient conditions for infinite-dimensional systems whose entanglement is not completely lost in a finite time during its decoherence by a passive interaction with local vacuum environments. The sufficient conditions allow us to clarify a ... More
Dynamics of Nonlocality for A Two-Mode Squeezed State in Thermal EnvironmentMar 18 2000We investigate the time evolution of nonlocality for a two-mode squeezed state in the thermal environment. The initial two-mode pure squeezed state is nonlocal with a stronger nonlocality for a larger degree of squeezing. It is found that the larger the ... More
Multipartite entanglement for entanglement teleportationJan 17 2002Nov 26 2002The scheme for entanglement teleportation is proposed to incorporate multipartite entanglement of four qubits as a quantum channel. Based on the invariance of entanglement teleportation under arbitrary two-qubit unitary transformation, we derive relations ... More
Decoherence of Highly Mixed Macroscopic Quantum SuperpositionsMay 02 2007Sep 24 2008It is known that a macroscopic quantum superposition (MQS), when it is exposed to environment, decoheres at a rate scaling with the separation of its component states in phase space. This is more or less consistent with the well known proposition that ... More
Experimental Demonstration on Quantum Sensitivity to Available Information in Decision MakingApr 30 2018Jan 26 2019We present an experimental illustration on the quantum sensitivity of decision making machinery. In the decision making process, we consider the role of available information, say hint, whether it influences the optimal choices. To the end, we consider ... More
A generalized structure of Bell inequalities for bipartite arbitrary dimensional systemsDec 21 2005Aug 10 2007We propose a generalized structure of Bell inequalities for arbitrary d-dimensional bipartite systems, which includes the existing two types of Bell inequalities introduced by Collins-Gisin-Linden-Massar-Popescu [Phys. Rev. Lett. 88, 040404 (2002)] and ... More
Greenberger-Horne-Zeilinger theorem for N quditsMar 21 2013Oct 07 2013We generalize Greenberger-Horne-Zeilinger (GHZ) theorem to an arbitrary number of D-dimensional systems. Contrary to conventional approaches using compatible composite observables, we employ incompatible and concurrent observables, whose common eigenstate ... More
Quantum plasmonics with a metal nanoparticle arrayDec 29 2011Jun 22 2012We investigate an array of metal nanoparticles as a channel for nanophotonic quantum communication and the generation of quantum plasmonic interference. We consider the transfer of quantum states, including single-qubits as plasmonic wavepackets, and ... More
Irreducibility of coherent statesJul 06 2016Sep 27 2016We suggest an optical method which tests a nonclassical feature with a coherent state input. The test is designed with a multiplexer of on/off detectors and post-selection, adopting sub-binomiality as a nonclassical feature, replacing Mandel's $Q$-factor. ... More
Testing genuine multipartite nonlocality in phase spaceNov 21 2012We demonstrate genuine three-mode nonlocality based on phase space formalism. A Svetlichny-type Bell inequality is formulated in terms of the $s$-parameterized quasiprobability function. We test such tool using exemplary forms of three-mode entangled ... More
A quantum speedup in machine learning: Finding a N-bit Boolean function for a classificationMar 25 2013Oct 14 2014We compare quantum and classical machines designed for learning an N-bit Boolean function in order to address how a quantum system improves the machine learning behavior. The machines of the two types consist of the same number of operations and control ... More
Partial Teleportation of Entanglement in the Noisy EnvironmentMar 16 2000Partial teleportation of entanglement is to teleport one particle of an entangled pair through a quantum channel. This is conceptually equivalent to quantum swapping. We consider the partial teleportation of entanglement in the noisy environment, employing ... More
Procedures for realizing an approximate universal NOT gateAug 10 2012Dec 19 2012We consider procedures to realize an approximate universal NOT gate in terms of average fidelity and fidelity deviation. The average fidelity indicates the optimality of operation on average, while the fidelity deviation does the universality of operation. ... More
Generating a Schrödinger-cat-like state via a coherent superposition of photonic operationsJun 17 2012We propose an optical scheme to generate a superposition of coherent states with enhanced size adopting an interferometric setting at the single-photon level currently available in the laboratory. Our scheme employs a nondegenerate optical parametric ... More
Experimentally realizable characterizations of continuous variable Gaussian statesJun 06 2002Measures of entanglement, fidelity and purity are basic yardsticks in quantum information processing. We propose how to implement these measures using linear devices and homodyne detectors for continuous variable Gaussian states. In particular, the test ... More
Conditions for Factorizable Output From a Beam splitterJun 10 2009A beam splitter is one of the most important devices in an optics laboratory because of its handiness and versatility; equivalent devices are found in various quantum systems to couple two subsystems or to interfere them. While it is normal that two independent ... More
Probabilistic nonlocal gate operation via imperfect entanglementJan 22 2001Nonlocal gate operation is based on sharing an ancillary pair of qubits in perfect entanglement. When the ancillary pair are partially entangled, the efficiency of the gate operation drops. Using general transformations, we devise probabilistic nonlocal ... More
Critical behavior in ultra-strong-coupled oscillatorsMar 30 2012Jun 23 2012We investigate the strong coupling regime of a linear $x$-$x$ coupled harmonic oscillator system, by performing a direct diagonalization of the hamiltonian. It is shown that the $x$-$x$ coupled hamiltonian can be equivalently described by a Mach-Zehnder-type ... More
Wringing Out Better No-signaling MonogamiesDec 04 2018We show that simple geometric properties of probabilistic spaces, in conjunction with no-signaling principle, lead to strong monogamies for a large class of Bell type inequalities. Additionally, using the same geometric approach, we derive a new tripartite, ... More
Quantum Secure Communication with W StatesApr 01 2002Aug 22 2002A W state is pair-wisely entangled, belonging to the different class from Greenberger, Horne, and Zeilinger (GHZ) state. We show that the W state enables three variant protocols, that is, quantum key distribution between several parts, quantum secret ... More
Strategy for quantum algorithm design assisted by machine learningJan 07 2013Jul 17 2014We propose a method for quantum algorithm design assisted by machine learning. The method uses a quantum-classical hybrid simulator, where a "quantum student" is being taught by a "classical teacher." In other words, in our method, the learning system ... More
Optimal conclusive teleportation of a d-dimensional unknown stateDec 18 2000Dec 21 2000We formulate a conclusive teleportation protocol for a system in d-dimensional Hilbert space utilizing the positive operator valued measurement at the sending station. The conclusive teleportation protocol ensures some perfect teleportation events when ... More
Operational quasiprobabilities for quditsJun 29 2012Nov 25 2013We propose an operational quasiprobability function for qudits, enabling a comparison between quantum and hidden-variable theories. We show that the quasiprobability function becomes positive semidefinite if consecutive measurement results are described ... More
Quantum Learning MachineMar 20 2008Mar 31 2008We propose a novel notion of a quantum learning machine for automatically controlling quantum coherence and for developing quantum algorithms. A quantum learning machine can be trained to learn a certain task with no a priori knowledge on its algorithm. ... More
Using macroscopic entanglement to close the detection loophole in Bell inequalityDec 18 2011Jun 01 2012We consider a Bell-like inequality performed using various instances of multi-photon entangled states to demonstrate that losses occurring after the unitary transformations used in the nonlocality test can be counteracted by enhancing the "size" of such ... More
Entanglement purification for high dimensional multipartite systemsDec 21 2005Aug 10 2007We propose an entanglement purification protocol for high-dimensional multipartite systems. In the protocol we can select a subensemble in a pure generalized Greenberger-Horne-Zeilinger (GHZ) state. This post-selection can be made by detecting the noise ... More
Can a stochastic ensemble computing machine imitate quantum computation?Apr 26 2016"Where do classical and quantum computers fit in?" or "what can and cannot they do?" have been long-standing questions. In particular, drawing a clear borderline between classical and quantum computations is obscure and still remains controversial. With ... More
Phonon-induced dynamic resonance energy transferApr 15 2013May 08 2014In a network of interacting quantum systems achieving fast coherent energy transfer is a challenging task. While quantum systems are susceptible to a wide range of environmental factors, in many physical settings their interactions with quantized vibrations, ... More
Robust-to-loss entanglement generation using a quantum plasmonic nanoparticle arrayMar 20 2013Aug 13 2013We introduce a scheme for generating entanglement between two quantum dots using a plasmonic waveguide made from an array of metal nanoparticles. We show that the scheme is robust to loss, enabling it to work over long distance plasmonic nanoparticle ... More
Experimental demonstration of error-insensitive approximate universal-NOT gatesMar 17 2014We propose and experimentally demonstrate an approximate universal-NOT (U-NOT) operation that is robust against operational errors. In our proposal, the U-NOT operation is composed of stochastic unitary operations represented by the vertices of regular ... More
Role of Energy-Level Mismatches in a Multi-Pathway Complex of PhotosynthesisFeb 16 2013Considering a multi-pathway structure in a light-harvesting complex of photosynthesis, we investigate the role of energy-level mismatches between antenna molecules in transferring the absorbed energy to a reaction center. We find a condition in which ... More
Quantifiable simulation of quantum computation beyond stochastic ensemble computationApr 26 2016Aug 24 2018In this study, a distinctive feature of quantum computation (QC) is characterized. To this end, a seemingly-powerful classical computing model, called "stochastic ensemble machine (SEnM)," is considered. The SEnM runs with an ensemble consisting of finite ... More
Quantum noise reduction in intensity-sensitive surface plasmon resonance sensorsMay 15 2017Sep 21 2017We investigate the use of twin-mode quantum states of light with symmetric statistical features in their photon number for improving intensity-sensitive surface plasmon resonance (SPR) sensors. For this purpose, one of the modes is sent into a prism setup ... More
Comment on `Energy transfer, entanglement and decoherence in a molecular dimer interacting with a phonon bath'Dec 16 2013We show that the influence of the shared phonon bath considered in H. Hossein-Nejad and G. D. Scholes, New J. Phys. 12, 065045 (2010) on the exciton transfer in a two-molecule system can be reproduced by that of an independent bath model.
Multi-setting Bell inequality for quditsOct 16 2008We propose a generalized Bell inequality for two three-dimensional systems with three settings in each local measurement. It is shown that this inequality is maximally violated if local measurements are configured to be mutually unbiased and a composite ... More
Multi-setting Greenberger-Horne-Zeilinger theoremMar 28 2013Feb 26 2014We present a generalized Greenberger-Horne-Zeilinger (GHZ) theorem, which involves more than two local measurement settings for some parties, and cannot be reduced to one with less settings. Our results hold for an odd number of parties. We use a set ... More
Quantum heuristic algorithm for traveling salesman problemApr 23 2010Nov 06 2012We propose a quantum heuristic algorithm to solve a traveling salesman problem by generalizing Grover search. Sufficient conditions are derived to greatly enhance the probability of finding the tours with extremal costs, reaching almost to unity and they ... More
Experimental demonstration of quantum learning speed-up with classical input dataJun 05 2017Nov 23 2018We consider quantum-classical hybrid machine learning in which large-scale input channels remain classical and small-scale working channels process quantum operations conditioned on classical input data. This does not require the conversion of classical ... More
Cross-Kerr-based information transfer processesNov 24 2005The realization of nonclassical states is an important task for many applications of quantum information processing. Usually, properly tailored interactions, different from goal to goal, are considered in order to accomplish specific tasks within the ... More
A classical-quantum hybrid oracle architecture for Boolean oracle identification in the noisy intermediate-scale quantum eraMay 14 2019Quantum algorithms have the potential to be very powerful. However, to exploit quantum parallelism, some quantum algorithms require an embedding of large classical data into quantum states. This embedding can cost a lot of resources, for instance by implementing ... More
Quantum-mechanical machinery for rational decision-making in classical guessing gameAug 20 2015Nov 23 2015In quantum game theory, one of the most intriguing and important questions is, "Is it possible to get quantum advantages without any modification of the classical game?" The answer to this question so far has largely been negative. So far, it has usually ... More
Completely-Positive Non-Markovian DecoherenceMar 02 2004We propose an effective Hamiltonian approach to investigate decoherence of a quantum system in a non-Markovian reservoir, naturally imposing the complete positivity on the reduced dynamics of the system. The formalism is based on the notion of an effective ... More
Negative quasiprobability in an operational contextSep 27 2018Negative probability values have been widely employed as an indicator of the nonclassicality of quantum systems. Known as a quasiprobability distribution, they are regarded as a useful tool that provides significant insight into the underlying fundamentals ... More
Optical Investigations of Charge Gap in Orbital Ordered La1/2Sr3/2MnO4Mar 22 1999Temperature and polarization dependent electronic structure of La1/2Sr3/2MnO4 were investigated by optical conductivity analyses. With decreasing temperature, for E//ab, a broad mid-infrared (MIR) peak of La1/2Sr3/2MnO4 becomes narrower and moves to the ... More
Restriction estimates to complex hyper-surfacesMar 11 2019The restriction problem is better understood for hyper-surfaces and recent progresses have been made by bilinear and multilinear approaches and most recently polynomial partitioning method which is combined with those estimates. However, for surfaces ... More
Estimating Large Precision Matrices via Modified Cholesky DecompositionJul 04 2017We introduce the $k$-banded Cholesky prior for estimating a high-dimensional bandable precision matrix via the modified Cholesky decomposition. The bandable assumption is imposed on the Cholesky factor of the decomposition. We obtained the P-loss convergence ... More
The Three Dimensional Structural Shape of the Gravitational Potential in the Local GroupMay 10 2006Jun 19 2008The Local Group is a small galaxy cluster with the membership of 62 nearby galaxies including the Milky Way and M31. Although the Local Group has yet to be virialized, it interacts with the surrounding matter as one gravitationally bound system. To understand ... More
On the structure of certain valued fieldsAug 27 2016Sep 07 2018For any two complete discrete valued fields $K_1$ and $K_2$ of mixed characteristic with perfect residue fields, we show that if each pair of $n$-th residue rings is isomorphic for each $n\ge1$, then $K_1$ and $K_2$ are isometric and isomorphic. More ... More
Generalizations of the Choe-Hoppe helicoid and Clifford cones in Euclidean spaceOct 13 2014Oct 26 2015Our goal is to generalize the Choe-Hoppe helicoid and Clifford cones in Euclidean space. By sweeping out $L$ indpendent Clifford cones in ${\mathbb{R}}^{2N+2}$ via the multi-screw motion, we construct minimal submanifolds in ${\mathbb{R}}^{L(2N+2)+1}$. ... More
Restriction estimates to complex hypersurfacesMar 11 2019Mar 12 2019The restriction problem is better understood for hypersurfaces and recent progresses have been made by bilinear and multilinear approaches and most recently polynomial partitioning method which is combined with those estimates. However, for surfaces with ... More
State transfer with quantum side informationAug 14 2017Mar 16 2018We first consider quantum communication protocols between a sender Alice and a receiver Bob, which transfer Alice's quantum information to Bob by means of non-local resources, such as classical communication, quantum communication, and entanglement. In ... More
A New Efficient Key Management Protocol for Wireless Sensor and Actor NetworksDec 03 2009Research on sensor networks has become much more active and is currently being applied to many different fields. However since sensor networks are limited to only collecting and reporting information regarding a certain event, and requires human intervention ... More
On the structure of certain valued fieldsAug 27 2016Sep 19 2016For any two complete discrete valued fields $K_1$ and $K_2$ of mixed characteristic with perfect residue fields, we show that if each pair of $n$-th residue rings is isomorphic for each $n\ge1$, then $K_1$ and $K_2$ are isometric and isomorphic. More ... More
The Variation of Galaxy Morphological Type with the Shear of EnvironmentJan 10 2008Jul 28 2008Recent N-body simulations have shown that the assembly history of galactic halos depend on the density of large-scale environment. It implies that the galaxy properties like age and size of bulge may also vary with the surrounding large-scale structures, ... More
Reconstructing the Intrinsic Triaxial Shape of the Virgo ClusterApr 11 2007To use galaxy clusters as a cosmological probe, it is important to account for their triaxiality. Assuming that the triaxial shapes of galaxy clusters are induced by the tidal interaction with the surrounding matter, Lee and Kang recently developed a ... More
Quantitative Analysis of a Transient Dynamics of a Gene Regulatory NetworkJun 28 2018Oct 16 2018In a stochastic process, noise often modifies the picture offered by the mean field dynamics. In particular, when there is an absorbing state, the noise erases a stable fixed point of the mean field equation from the stationary distribution, and turns ... More
Unbiased Global Optimization of Lennard-Jones Clusters for N <= 201 by Conformational Space Annealing MethodJul 29 2003We apply the conformational space annealing (CSA) method to the Lennard-Jones clusters and find all known lowest energy configurations up to 201 atoms, without using extra information of the problem such as the structures of the known global energy minima. ... More
A note on the Gunningham's formulaJun 30 2014Gunningham [G] constructed an extended topological quantum field theory (TQFT) to obtain a closed formula for all spin Hurwitz numbers. In this note, we use the gluing theorem in [LP2] to reprove the Gunningham's formula. We also describe a TQFT formalism ... More
Cross correlation of Cosmic Microwave background and Weak LensingOct 16 2015The integrated Sachs-Wolfe (ISW) effect and its non-linear extension Rees-Sciama (RS) effect provide us the information of the time evolution of gravitational potential. The cross-correlation between the cosmic microwave background (CMB) and the large ... More
The thermodynamics of quantum spacetime historiesOct 13 2015We show that the simplicity constraints, which define the dynamics of spin foam models, imply, and are implied by, the first law of thermodynamics, when the latter is applied to causal diamonds in the quantum spacetime. This result reveals an intimate ... More
Non-local beablesJul 30 2015I discuss the idea that the beables underlying quantum physics are non-local and relational, and give an example of a dynamical theory of such beables based on a matrix model, which is the bosonic sector of the BFSS model. Given that the same model has ... More
Dynamics of the cosmological and Newton's constantJul 05 2015A modification of general relativity is presented in which Newton's constant and the cosmological constant become a conjugate pair of dynamical variables.
The case for background independenceJul 25 2005The aim of this paper is to explain carefully the arguments behind the assertion that the correct quantum theory of gravity must be background independent. We begin by recounting how the debate over whether quantum gravity must be background independent ... More
A quantization of topological M theoryMar 17 2005A conjecture is made as to how to quantize topological M theory. We study a Hamiltonian decomposition of Hitchin's 7-dimensional action and propose a formulation for it in terms of 13 first class constraints. The theory has 2 degrees of freedom per point, ... More
The cubic matrix model and a duality between strings and loopsJun 19 2000We find evidence for a duality between the standard matrix formulations of M theory and a background independent theory which extends loop quantum gravity by replacing SU(2) with a supersymmetric and quantum group extension of SU(16). This is deduced ... More
General relativity as the equation of state of spin foamMay 24 2012Building on recent significant results of Frodden, Ghosh and Perez (FGP) and Bianchi, I present a quantum version of Jacobson's argument that the Einstein equations emerge as the equation of state of a quantum gravitational system. I give three criteria ... More
On limitations of the extent of inertial frames in non-commutative relativistic spacetimesJul 05 2010Aug 10 2010We study the interplay of non-locality and Lorentz invariance in a version of deformed or doubly special relativity (DSR) based on kappa-Minkowski spacetime. We find that Einstein's procedure for an inertial observer to assign coordinates to distant events ... More
The status of cosmological natural selectionDec 18 2006The problem of making predictions from theories that have landscapes of possible low energy parameters is reviewed. Conditions for such a theory to yield falsifiable predictions for doable experiments are given. It is shown that the hypothesis of cosmological ... More
The present moment in quantum cosmology: challenges to the arguments for the elimination of timeApr 29 2001Barbour, Hawking, Misner and others have argued that time cannot play an essential role in the formulation of a quantum theory of cosmology. Here we present three challenges to their arguments, taken from works and remarks by Kauffman, Markopoulou and ... More
Finite, diffeomorphism invariant observables in quantum gravityFeb 10 1993Two sets of spatially diffeomorphism invariant operators are constructed in the loop representation formulation of quantum gravity. This is done by coupling general relativity to an anti- symmetric tensor gauge field and using that field to pick out sets ... More
Strings as perturbations of evolving spin-networksJan 06 1998A connection between non-perturbative formulations of quantum gravity and perturbative string theory is exhibited, based on a formulation of the non-perturbative dynamics due to Markopoulou. In this formulation the dynamics of spin network states and ... More
Galactic disks as reaction-diffusion systemsDec 03 1996A model of a galactic disk is presented which extends the homogeneous one zone models by incorporating propagation of material and energy in the disk. For reasonable values of the parameters the homogeneous steady state is unstable to the development ... More
Cosmology as a Problem in Critical PhenomenaMay 16 1995Several problems in cosmology and astrophysics are described in which critical phenomena of various types may play a role. These include the organization of the disks of spiral galaxies, various aspects of the problem of structure formation in icosmology, ... More
A characterization of quasipositive Seifert surfaces (Constructions of quasipositive knots and links, III)Nov 15 2004This article was originally published in Topology 31 (1992). The present hyperTeXed redaction corrects a few typographical errors and updates the references.
Isolated critical points of mappings from $\mathbf{R}^4$ to $\mathbf{R}^2$ and a natural splitting of the Milnor number of a classical fibered link. Part I: Basic theory; examplesMar 04 2002Mar 04 2002From a fibered link in the 3-sphere may be constructed a field of not everywhere tangent 2-planes; when the fibered link is the link of an isolated critical point of a map from 4-space to the plane, the plane field is essentially the field of kernels ... More
Quadratic polynomials of small modulus cannot represent ORSep 29 2015Nov 12 2015An open problem in complexity theory is to find the minimal degree of a polynomial representing the $n$-bit OR function modulo composite $m$. This problem is related to understanding the power of circuits with $\text{MOD}_m$ gates where $m$ is composite. ... More
Quasi-sparse eigenvector diagonalization and stochastic error correctionAug 30 2000We briefly review the diagonalization of quantum Hamiltonians using the quasi-sparse eigenvector (QSE) method. We also introduce the technique of stochastic error correction, which systematically removes the truncation error of the QSE result by stochastically ... More
Pressure inequalities for nuclear and neutron matterJul 28 2004Dec 22 2005We prove several inequalities using lowest-order effective field theory for nucleons which give an upper bound on the pressure of asymmetric nuclear matter and neutron matter. We prove two types of inequalities, one based on convexity and another derived ... More
Dynamical Fermions in Hamiltonian Lattice Gauge TheoryOct 24 2001We describe a first attempt to understand dynamical fermions within a Hamiltonian framework. As a testing ground we study compact QED3 which shares some important features of QCD4 such as confinement, glueballs, mesons, and chiral symmetry breaking. We ... More
The role of Monte Carlo within a diagonalization/Monte Carlo schemeOct 31 2000We review the method of stochastic error correction which eliminates the truncation error associated with any subspace diagonalization. Monte Carlo sampling is used to compute the contribution of the remaining basis vectors not included in the initial ... More
Optimal Estimation and Prediction for Dense Signals in High-Dimensional Linear ModelsMar 20 2012Estimation and prediction problems for dense signals are often framed in terms of minimax problems over highly symmetric parameter spaces. In this paper, we study minimax problems over l2-balls for high-dimensional linear models with Gaussian predictors. ... More
Dense Signals, Linear Estimators, and Out-of-Sample Prediction for High-Dimensional Linear ModelsFeb 15 2011Mar 20 2012Motivated by questions about dense (non-sparse) signals in high-dimensional data analysis, we study the unconditional out-of-sample prediction error (predictive risk) associated with three popular linear estimators for high-dimensional linear models: ... More
Transforming floundering into successJul 30 2012We show how logic programs with "delays" can be transformed to programs without delays in a way which preserves information concerning floundering (also known as deadlock). This allows a declarative (model-theoretic), bottom-up or goal independent approach ... More
Practical Multiwriter Lock-Free Queues for "Hard Real-Time" Systems without CASSep 28 2007FIFO queues with a single reader and writer can be insufficient for "hard real-time" systems where interrupt handlers require wait-free guarantees when writing to message queues. We present an algorithm which elegantly and practically solves this problem ... More
Transforming Hidden Vector Encryption Schemes from Composite to Prime Order GroupsNov 09 2016Predicate encryption is a new type of public key encryption that enables searches on encrypted data. By using predicate encryption, we can search keywords or attributes on encrypted data without decrypting ciphertexts. Hidden vector encryption (HVE) is ... More
Amplitudes of low frequency modes in rotating B type starsNov 17 2011Using weakly non-linear theory of oscillation, we estimate the amplitudes of low frequency modes in a slowly pulsating B (SPB) star, taking account of the effects of rotation on the modes. Applying the formulation by Schenk et al (2002), we compute non-linear ... More