Results for "Ka Ho Yuen"

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Tracing magnetic field morphology using the Velocity Gradient Technique in the presence of CO self-absorptionSep 26 2018Jan 30 2019Probing magnetic fields in self-gravitating molecular clouds are generally difficult even with the use of the polarimetry. Based on the properties of magneto-hydrodynamic (MHD) turbulence and turbulent reconnection, Velocity Gradient Technique (VGT) provides ... More
Tracing 3D distribution of magnetic fields with gradients of synchrotron polarizationJan 31 2018In this paper, we describe a new technique for probing galactic and extragalactic 2D and 3D distribution of magnetic field using synchrotron polarization. Fluctuations of magnetic field are elongated along the ambient magnetic field directions. As a result, ... More
Tilings of the Sphere by Geometrically Congruent Pentagons IOct 08 2013May 08 2014We show that there are no edge-to-edge tilings of the sphere by congruent pentagons beyond the minimal dodecahedron tiling, such that there is a tile with all vertices having degree 3 and the edge length combinations are three of the five possibilities. ... More
Diagnostics of turbulence properties through Velocity Gradient Amplitudes: Theory and ObservationsJan 31 2018Based on the properties of magneto-hydrodynamic (MHD) turbulence, the recent development of the Velocity Gradient Technique (VGT) allows observers to trace magnetic field directions using spectroscopic information. In this paper, we explore how the amplitudes ... More
Beamforming Matrix Quantization with Variable Feedback RateJun 20 2008We propose an improved beamforming matrix compression by Givens Rotation with the use of variable feedback rate. The variable feedback rate means that the number of bits used to represent the quantized beamforming matrix is based on the value of the matrix. ... More
Adaptive mixed GMsFEM for flows in heterogeneous mediaJul 07 2015In this paper, we present two adaptive methods for the basis enrichment of the mixed Generalized Multiscale Finite Element Method (GMsFEM) for solving the flow problem in heterogeneous media. We develop an a-posteriori error indicator which depends on ... More
A comparison between Faraday Tomography and Synchrotron Polarization GradientsJan 23 2019Observations of synchrotron polarization at multiple frequencies in the presence of Faraday rotation can provide a way to reconstruct the 3D magnetic field distribution. In this paper we compare the well known Faraday Tomography (FT, Burn 1966) technique ... More
Exact Results for the Kepler Problem in General RelativityJul 25 2008Jul 27 2008Exact results are derived, specifically the perihelion shift and the Kepler orbit, for a bound test particle in the Schwarzschild metric with cosmological constant $\Lambda=0$. A series expansion, of $\Delta\phi = 2(2(1-2M/p(3-e))^{-1/2} K((4eM/p)/(1-2M/p(3-e)))-\pi)$, ... More
Dispersion of velocity gradients: Mapping magnetization with the Velocity Gradient TechniqueFeb 08 2018Recent developments of the Velocity Gradient Technique (VGT) show that the velocity provides a robust measure of magnetic field direction. In this paper, we use velocity centroids as the measures of velocity and propose a new way of studying media magnetization. ... More
Self-Similar Solutions with Elliptic Symmetry for the Compressible Euler and Navier-Stokes Equations in R^{N}Apr 19 2011Based on Makino's solutions with radially symmetry, we extend the corresponding ones with elliptic symmetry for the compressible Euler and Navier-Stokes equations in R^{N} (N\geq2). By the separation method, we reduce the Euler and Navier-Stokes equations ... More
Jet schemes of determinantal varietiesAug 25 2006This article studies the scheme structure of the jet schemes of determinantal varieties. We show that in general, these jet schemes are not irreducible. In the case of the determinantal variety $X$ of $r \times s$ matrices of rank at most one, we give ... More
A parallel repetition theorem for all entangled gamesApr 15 2016The behavior of games repeated in parallel, when played with quantumly entangled players, has received much attention in recent years. Quantum analogues of Raz's classical parallel repetition theorem have been proved for many special classes of games. ... More
A quantum lower bound for distinguishing random functions from random permutationsOct 10 2013Dec 20 2013The problem of distinguishing between a random function and a random permutation on a domain of size $N$ is important in theoretical cryptography, where the security of many primitives depend on the problem's hardness. We study the quantum query complexity ... More
Some Exact Blowup Solutions to the Pressureless Euler Equations in R^NOct 07 2009The pressureless Euler equations can be used as simple models of cosmology or plasma physics. In this paper, we construct the exact solutions in non-radial symmetry to the pressureless Euler equations in $R^{N}:$% [c]{c}% \rho(t,\vec{x})=\frac{f(\frac{1}{a(t)^{s}}\underset{i=1}{\overset ... More
Analytical Blowup Solutions to the 2-dimensional Isothermal Euler-Poisson Equations of Gaseous Stars IIMay 31 2009Jul 29 2009This article is the continued version of the analytical blowup solutions for 2-dimensional Euler-Poisson equations \cite{Y1}. With extension of the blowup solutions with radial symmetry for the isothermal Euler-Poisson equations in $R^{2}$, other special ... More
Analytical Blowup Solutions to the 3-dimensional Pressureless Navier-Stokes-Poisson Equations with Density-dependent ViscosityNov 03 2008We study the pressureless Navier--Stokes-Poisson equations of describing the evolution of the gaseous star in astrophysics. The isothermal blowup solutions of Yuen, to the Euler-Poisson equations in R2, can be extended to the pressureless Navier-Stokes-Poisson ... More
Security of Quantum Key DistributionFeb 24 2016The security issues facing quantum key distribution (QKD) are explained, herein focusing on those issues that are cryptographic and information theoretic in nature and not those based on physics. The problem of security criteria is addressed. It is demonstrated ... More
Analytical Blowup Solutions to the Isothermal Euler-Poisson Equations of Gaseous Stars in R^NMay 31 2009This article is the continued version of the analytical blowup solutions for 2-dimensional Euler-Poisson equations in "M.W. Yuen, Analytical Blowup Solutions to the 2-dimensional Isothermal Euler-Poisson Equations of Gaseous Stars, J. Math. Anal. Appl. ... More
Analytical Solutions to the Navier-Stokes EquationsNov 03 2008Feb 19 2009With the previous results for the analytical blowup solutions of the N-dimensional Euler-Poisson equations, we extend the similar structure to construct an analytical family of solutions for the isothermal Navier-Stokes equations and pressureless Navier-Stokes ... More
A Helium nanodrop bouncing off a wallJul 25 2003Aug 10 2003We investigate numerically the quantum collision between a stable Helium nanodrop and an infinitely hard wall in one dimension. The scattering outcome is compared to the same event omitting the quantum pressure. Only the quantum process reflects the effect ... More
Sums of quadratic functions with two discriminantsMar 23 2017Zagier in [4] discusses a construction of a function $F_{k,D}(x)$ defined for an even integer $k \geq 2$, and a positive discriminant $D$. This construction is intimately related to half-integral weight modular forms. In particular, the average value ... More
Similarity reductions and new nonlinear exact solutions for the 2D incompressible Euler equationsJan 26 2014For the 2D and 3D Euler equations, their existing exact solutions are often in linear form with respect to variables x,y,z. In this paper, the Clarkson-Kruskal reduction method is applied to reduce the 2D incompressible Euler equations to a system of ... More
Unconditional security in quantum bit commitmentJun 01 2001The commitment of bits between two mutually distrustful parties is a powerful cryptographic primitive with which many cryptographic objectives can be achieved. It is widely believed that unconditionally secure quantum bit commitment is impossible due ... More
Infinite Randomness Expansion and Amplification with a Constant Number of DevicesOct 24 2013Apr 01 2014We present a device-independent randomness expansion protocol, involving only a constant number of non-signaling quantum devices, that achieves \emph{infinite expansion}: starting with $m$ bits of uniform private randomness, the protocol can produce an ... More
Effect of Transmission Loss on The Fundamental Security of Quantum Key DistributionSep 06 2011It is shown that the effect of transmission loss has often not been properly taken into account in the security proofs on quantum key distribution. A class of general attacks to be called probabilistic re-sends attack is described that has not been accounted ... More
QBC3: An Unconditionally Secure Quantum Bit Commitment ProtocolFeb 07 2007Mar 19 2007This article describes a quantum bit commitment protocol, QBC3, based on entanglement destruction via forced measurements and proves its unconditional security. Some comments on the current status of the field are also made.
Mathematical Modeling of Physical and Engineering Systems in Quantum InformationFeb 06 2007Mar 19 2007Several concrete examples in quantum information are discussed to demonstrate the importance of proper modeling that relates the mathematical description to real-world applications. In particular, it is shown that some commonly accepted conclusions are ... More
Unconditionally Secure Quantum Bit Commitment Is PossibleJun 23 2000Oct 18 2000Bit commitment involves the submission of evidence from one party to another so that the evidence can be used to confirm a later revealed bit value by the first party, while the second party cannot determine the bit value from the evidence alone. It is ... More
Performance Analysis and Optimization for Interference Alignment over MIMO Interference Channels with Limited FeedbackFeb 03 2014In this paper, we address the problem of interference alignment (IA) over MIMO interference channels with limited channel state information (CSI) feedback based on quantization codebooks. Due to limited feedback and hence imperfect IA, there are residual ... More
Partial Third-Party Information Exchange with Network CodingFeb 15 2013In this paper, we consider the problem of exchanging channel state information in a wireless network such that a subset of the clients can obtain the complete channel state information of all the links in the network. We first derive the minimum number ... More
Joint Optimization of Spectrum Sensing and Accessing in Multiuser MISO Cognitive NetworksJun 30 2014In this paper, a joint spectrum sensing and accessing optimization framework for a multiuser cognitive network is proposed to significantly improve spectrum efficiency. For such a cognitive network, there are two important and limited resources that should ... More
Geometric Bijections Between Spanning Trees and Break DivisorsSep 09 2015The Jacobian group ${\rm Jac}(G)$ of a finite graph $G$ is a group whose cardinality is the number of spanning trees of $G$. $G$ also has a tropical Jacobian which has the structure of a real torus; using the notion of break divisors, An et al. obtained ... More
Self-similar Fragmentation Regulated by Magnetic Fields in a Massive Star Forming FilamentOct 24 2015Most molecular clouds are filamentary or elongated. Among those forming low-mass stars, their long axes tend to be either parallel or perpendicular to the large-scale (10-100 pc) magnetic field (B-field) in the surrounding inter cloud medium. This arises ... More
Voltage-Controlled Berry Phases in Two Coupled Quantum DotsJan 25 2008The voltage-controlled Berry phases in two vertically coupled InGaAs/GaAs quantum dots are investigated theoretically. It is found that Berry phases can be changed dramatically from 0 to 2$\pi$ (or 2$\pi$ to 0) only simply by turning the external voltage. ... More
Some Physics And System Issues In The Security Analysis Of Quantum Key Distribution ProtocolsMay 07 2014In this paper we review a number of issues on the security of quantum key distribution (QKD) protocols that bear directly on the relevant physics or mathematical representation of the QKD cryptosystem. It is shown that the cryptosystem representation ... More
Security Significance of the Trace Distance Criterion in Quantum Key DistributionSep 13 2011Nov 09 2011The security significance of the trace distance security criterion $d$ is analyzed in terms of operational probabilities of an attacker's success in identifying different subsets of the generated key, both during the key generation process and when the ... More
KCQ: A New Approach to Quantum Cryptography I. General Principles and Key GenerationNov 10 2003Jul 30 2004A new approach to quantum cryptography to be called KCQ, keyed communication in quantum noise, is developed on the basis of quantum detection and communication theory for classical information transmission. By the use of a shared secret key that determines ... More
How to Build Unconditionally Secure Quantum Bit Commitment ProtocolsMay 23 2003Jan 14 2004The ``impossibility proof'' on unconditionally secure quantum bit commitment is critically analyzed. Many possibilities for obtaining a secure bit commitment protocol are indicated, purely on the basis of two-way quantum communications, which are not ... More
Fundamental Insecurity of Multi-Photon Sources Under Photon-Number Splitting Attacks in Quantum Key DistributionJul 30 2012Aug 06 2012A simple photon-number splitting attack is described which works on any lossy quantum key distribution system with a multi-photon source independently of the mean source photon number, and with no induced error rate. In particular, it cannot be detected ... More
Uncertainty Principle and the Standard Quantum LimitsOct 10 2005The role of the Uncertainty Principle is examined through the examples of squeezing, information capacity, and position monitoring. It is suggested that more attention should be directed to conceptual considerations in quantum information science and ... More
Finite Groups Embeddable in Division RingsMay 03 2000Finite groups that are embeddable in the multiplicative groups of division rings $K$ were completely determined by S. A. Amitsur in 1955. In case $K$ has characteristic $p>0$, the only possible finite subgroups of $K^*$ are cyclic groups, according to ... More
Applications of Partially Quenched Chiral Perturbation TheoryNov 17 1997Feb 24 1998Partially quenched theories are theories in which the valence- and sea-quark masses are different. In this paper we calculate the nonanalytic one-loop corrections of some physical quantities: the chiral condensate, weak decay constants, Goldstone boson ... More
Chiral perturbation theory for K+ to pi+ pi0 decay in the continuum and on the latticeFeb 14 1997May 16 1997In this paper we use one-loop chiral perturbation theory in order to compare lattice computations of the K+ to pi+ pi0 decay amplitude with the experimental value. This makes it possible to investigate three systematic effects that plague lattice computations: ... More
Exact joint laws associated with spectrally negative Levy processes and applications to insurance risk theoryJan 03 2011Feb 25 2014We consider the spectrally negative Levy processes and determine the joint laws for the quantities such as the first and last passage times over a fixed level, the overshoots and undershoots at first passage, the minimum, the maximum and the duration ... More
On Two-way Communications for Cooperative Multiple Source Pairs Through a Multi-antenna RelayDec 10 2010We study amplified-and-forward (AF)-based two-way relaying (TWR) with multiple source pairs, which are exchanging information through the relay. Each source has single antenna and the relay has multi-antenna. The optimal beamforming matrix structure that ... More
Achieving Near-Capacity at Low SNR on a Multiple-Antenna Multiple-User ChannelJun 20 2008We analyze the sensitivity of the capacity of a multi-antenna multi-user system to the number of users being served. We show analytically that, for a given desired sum-rate, the extra power needed to serve a subset of the users at low SNR (signal-to-noise ... More
Pulsar Electrodynamics: an unsolved problemApr 13 2016Pulsar electrodynamics is reviewed emphasizing the role of the inductive electric field in an oblique rotator and the incomplete screening of its parallel component by charges, leaving `gaps' with $E_\parallel\ne0$. The response of the plasma leads to ... More
A vanishing Ext-branching theorem for $(\mathrm{GL}_{n+1}(F), \mathrm{GL}_n(F))$Mar 24 2018We prove a conjecture of Dipendra Prasad on the Ext-branching problem from $\mathrm{GL}_{n+1}(F)$ to $\mathrm{GL}_n(F)$, where $F$ is a $p$-adic field.
Bernstein-Zelevinsky derivatives: a Hecke algebra approachFeb 04 2017May 19 2017Let $G$ be a general linear group over a $p$-adic field. It is well known that Bernstein components of the category of smooth representations of $G$ are described by Hecke algebras arising from Bushnell-Kutzko types. We describe the Bernstein components ... More
Coarsening to Chaos-Stabilized FrontsJun 01 2010We investigate a model for pattern formation in the presence of Galilean symmetry proposed by Matthews and Cox [Phys.\ Rev.\ E \textbf{62}, R1473 (2000)], which has the form of coupled generalized Burgers and Ginzburg-Landau-type equations. With only ... More
Spectrality of Self-Similar TilesSep 16 2013We call a set $K \subset {\mathbb R}^s$ with positive Lebesgue measure a {\it spectral set} if $L^2(K)$ admits an exponential orthonormal basis. It was conjectured that $K$ is a spectral set if and only if $K$ is a tile (Fuglede's conjecture). Despite ... More
Temperature Dependence of Violation of Bell's Inequality in Coupled Quantum Dots in a MicrocavityMay 22 2007Bell's inequality in two coupled quantum dots within cavity QED, including Forster and exciton-phonon interactions, is investigated theoretically. It is shown that the environmental temperature has a significant impact on Bell's inequality.
$H^2$--Convergence of least-squares kernel collocation methodsJan 02 2018The strong-form asymmetric kernel-based collocation method, commonly referred to as the Kansa method, is easy to implement and hence is widely used for solving engineering problems and partial differential equations despite the lack of theoretical support. ... More
Minimizing atomic configurations of short range pair potentials in two dimensions: crystallization in the Wulff shapeSep 04 2009We investigate ground state configurations of atomic systems in two dimensions interacting via short range pair potentials. As the number of particles tends to infinity, we show that low-energy configurations converge to a macroscopic cluster of finite ... More
On differential characteristic classesNov 15 2013Oct 16 2014In this paper we give explicit formulas of differential characteristic classes of principal $G$-bundles with connections and prove their expected properties. In particular, we obtain explicit formulas for differential Chern classes, differential Pontryagin ... More
Quantum process tomography of molecular dimers from two-dimensional electronic spectroscopy I: General theory and application to homodimersJan 14 2011Is it possible to infer the time evolving quantum state of a multichromophoric system from a sequence of two-dimensional electronic spectra (2D-ES) as a function of waiting time? Here we provide a positive answer for a tractable model system: a coupled ... More
Blowup of Regular Solutions for the Relativistic Euler-Poisson EquationsSep 04 2015In this paper, we study the blowup phenomena for the regular solutions of the isentropic relativistic Euler-Poisson equations with a vacuum state in spherical symmetry. Using a general family of testing functions, we obtain new blowup conditions for the ... More
Comment on "Quantum theory of collective strong coupling of molecular vibrations with a microcavity mode"Sep 08 2017We have found missing terms and incorrect signs in the secular master equations reported by Del Pino et. al., New J. Phys., 17 (2015), 053040 for vibrational polariton relaxation. Inclusion of these terms and signs are essential to yield correct (vanishing) ... More
On Igusa zeta functions of monomial idealsSep 11 2005Sep 22 2006We show that the real parts of the poles of the Igusa zeta function of a monomial ideal can be computed from the torus-invariant divisors on the normalized blowing-up along the ideal. Moreover, we show that every such number is a root of the Bernstein-Sato ... More
The dimension of an amoebaDec 19 2018Answering a question by Nisse and Sottile, we derive a formula for the dimension of the amoeba of an irreducible algebraic variety.
Exploiting Large-Scale MIMO Techniques for Physical Layer Security with Imperfect Channel State InformationJul 28 2014In this paper, we study the problem of physical layer security in large-scale multiple input multiple output (LS-MIMO) systems. The large number of antenna elements in LS-MIMO system is exploited to enhance transmission security and improve system performance, ... More
Resource Allocation for Cost Minimization in Limited Feedback MU-MIMO Systems with Delay GuaranteeNov 05 2013In this paper, we design a resource allocation framework for the delay-sensitive Multi-User MIMO (MU-MIMO) broadcast system with limited feedback. Considering the scarcity and interrelation of the transmit power and feedback bandwidth, it is imperative ... More
Adaptive Mode Selection in Multiuser MISO Cognitive Networks with Limited Cooperation and FeedbackOct 16 2013In this paper, we consider a multiuser MISO downlink cognitive network coexisting with a primary network. With the purpose of exploiting the spatial degree of freedom to counteract the inter-network interference and intra-network (inter-user) interference ... More
A Continuous Vector-Perturbation for Multi-Antenna Multi-User CommunicationJun 23 2008The sum-rate of the broadcast channel in a multi-antenna multi-user communication system can be achieved by using precoding and adding a regular perturbation to the data vector. The perturbation can be removed by the modulus function, thus transparent ... More
Non-homogeneous distributed storage systemsAug 10 2012This paper describes a non-homogeneous distributed storage systems (DSS), where there is one super node which has a larger storage size and higher reliability and availability than the other storage nodes. We propose three distributed storage schemes ... More
Distributionally Robust Inference for Extreme Value-at-RiskFeb 15 2019Under general multivariate regular variation conditions, the extreme Value-at-Risk of a portfolio can be expressed as an integral of a known kernel with respect to a generally unknown spectral measure supported on the unit simplex. The estimation of the ... More
Nonlift weight two paramodular eigenform constructionsMay 10 2018We complete the construction of the nonlift weight two cusp paramodular Hecke eigenforms for prime levels N<600, which arise in conformance with the paramodular conjecture of Brumer and Kramer.
On an index theorem by BismutJan 07 2015Jul 16 2015In this paper we give a proof of an index theorem by Bismut. As a consequence we obtain another proof of the Grothendieck-Riemann-Roch theorem in differential cohomology.
Charge transfer satellites in x-ray spectra of transition metal oxidesNov 19 2013Strongly correlated materials such as transition metal oxides (TMOs) often exhibit large satellites in their x-ray photoemission (XPS) and x-ray absorption spectra (XAS). These satellites arise from localized charge-transfer (CT) excitations that accompany ... More
Time complexity of concurrent programsNov 16 2015We study the problem of automatically computing the time complexity of concurrent object-oriented programs. To determine this complexity we use intermediate abstract descriptions that record relevant information for the time analysis (cost of statements, ... More
Landmark-matching Transformation with Large Deformation via n-dimensional Quasi-conformal MapsFeb 27 2014May 11 2015We propose a new method to obtain landmark-matching transformations between n-dimensional Euclidean spaces with large deformations. Given a set of feature correspondences, our algorithm searches for an optimal folding-free mapping that satisfies the prescribed ... More
Functional Renormalization Group Analysis of the Half-filled One-dimensional Extended Hubbard ModelMay 16 2005Feb 14 2006We study the phase diagram of the half-filled one-dimensional extended Hubbard model at weak coupling using a novel functional renormalization group (FRG) approach. The FRG method includes in a systematic manner the effects of the scattering processes ... More
Shorter signed circuit covers of graphsJun 12 2017A signed circuit is a minimal signed graph (with respect to inclusion) that admits a nowhere-zero flow. We show that each flow-admissible signed graph on $m$ edges can be covered by signed circuits of total length at most $(3+2/3)\cdot m$, improving a ... More
Robust Randomness Amplifiers: Upper and Lower BoundsMay 28 2013Jun 23 2013A recent sequence of works, initially motivated by the study of the nonlocal properties of entanglement, demonstrate that a source of information-theoretically certified randomness can be constructed based only on two simple assumptions: the prior existence ... More
Borcherds Products EverywhereDec 22 2013We prove the Borcherds Products Everywhere Theorem, Theorem 6.6, that constructs holomorphic Borcherds Products from certain Jacobi forms that are theta blocks without theta denominator. The proof uses generalized valuations from formal series to partially ... More
Distributionally Robust Inference for Extreme Value-at-RiskFeb 15 2019Feb 20 2019Under general multivariate regular variation conditions, the extreme Value-at-Risk of a portfolio can be expressed as an integral of a known kernel with respect to a generally unknown spectral measure supported on the unit simplex. The estimation of the ... More
Composing photomosaic images using clustering based evolutionary programmingApr 09 2018Photomosaic images are a type of images consisting of various tiny images. A complete form can be seen clearly by viewing it from a long distance. Small tiny images which replace blocks of the original image can be seen clearly by viewing it from a short ... More
Tilings of the Sphere by Edge Congruent PentagonsJan 04 2013Apr 14 2013We study edge-to-edge tilings of the sphere by edge congruent pentagons, under the assumption that there are tiles with all vertices having degree 3. We develop the technique of neighborhood tilings and apply the technique to completely classify edge ... More
Particle-hole cumulant approach for inelastic losses in x-ray spectraApr 22 2016Inelastic losses in core level x-ray spectra arise from many-body excitations, leading to broadening and damping as well as satellite peaks in x-ray photoemission (XPS) and x-ray absorption (XAS) spectra. Here we present a practical approach for calculating ... More
Generalized particle/hole cumulant approximation for the electron Green's functionJan 31 2014The cumulant expansion is a powerful approach for including correlation effects in electronic structure calculations beyond the GW approximation. However, current implementations are incomplete since they ignore terms that lead to partial occupation numbers ... More
Measure representation and multifractal analysis of complete genomesAug 28 2001This paper introduces the notion of measure representation of DNA sequences. Spectral analysis and multifractal analysis are then performed on the measure representations of a large number of complete genomes. The main aim of this paper is to discuss ... More
Random walks and induced Dirichlet forms on compact spaces of homogeneous typeApr 08 2018We extend our study of random walks and induced Dirichlet forms on self-similar sets [arXiv:1604.05440, 1612.01708] to compact spaces of homogeneous type $(K, \rho ,\mu)$. A successive partition on $K$ brings a natural augmented tree structure $(X, E)$ ... More
Reversible Superconductivity in Electrochromic Indium-Tin Oxide FilmsMar 21 2012Oct 09 2012Transparent conductive indium tin oxide (ITO) thin films, electrochemically intercalated with sodium or other cations, show tunable superconducting transitions with a maximum $T_c$ at 5 K. The transition temperature and the density of states, $D(E_F)$ ... More
Pomeranchuk Instability in a non-Fermi Liquid from HolographyMar 14 2012Sep 17 2012The Pomeranchuk instability, in which an isotropic Fermi surface distorts and becomes anisotropic due to strong interactions, is a possible mechanism for the growing number of experimental systems which display transport properties that differ along the ... More
Neutral Order Parameters in Metallic Criticality in d=2+1 from a Hairy Electron StarJun 16 2011We use holography to study the spontaneous condensation of a neutral order parameter in a (2+1)-dimensional field theory at zero-temperature and finite density, dual to the electron star background of Hartnoll and Tavanfar. An appealing feature of this ... More
Geometric phase of a central spin coupled to an antiferromagnetic environmentMar 05 2010Using the spin-wave approximation, we study the geometric phase (GP) of a central spin (signal qubit) coupled to an antiferromagnetic (AF) environment under the application of an external global magnetic field. The external magnetic field affects the ... More
Influence of an external magnetic field on the decoherence of a central spin coupled to an antiferromagnetic environmentJun 07 2007Using the spin wave approximation, we study the decoherence dynamics of a central spin coupled to an antiferromagnetic environment under the application of an external global magnetic field. The external magnetic field affects the decoherence process ... More
Harmonics suppression effect of the quasi-periodic undulator in SASE free-electron-laserMay 03 2013In this paper, the harmonics suppression effect of QPUs in SASE FEL is investigated. The numerical results show that the harmonics power is reduced by using QPUs, but the fundamental radiation power also has a pronounced decrease as the saturation length ... More
Holographic Stress Tensor for Kerr-AdS Black Holes and Local Failure on IR-UV ConnectionMay 26 2000Jun 07 2000We show that in general holographic stress tensor may contain a new term of divergence of a spacelike unit normal acceleration. Then, it is shown that in contrast to previous descriptions, a new stress tensor for Kerr-AdS solutions can be a traceless ... More
A Proof of the Generalized Second Law for Two-Dimensional Black HolesMar 16 2001Apr 25 2001We investigate the generalized second law for two-dimensional black holes in equilibrium (Hartle-Hawking) and nonequilibrium (Unruh) with the heat bath surrounding the black holes. We obtain a simple expression for the change of total entropy in terms ... More
Dominant Superconducting Fluctuations in the One-Dimensional Extended Holstein-Extended Hubbard modelJan 23 2013The search for realistic one-dimensional (1D) models that exhibit dominant superconducting (SC) fluctuations effects has a long history. In these 1D systems, the effects of commensurate band fillings--strongest at half-filling--and electronic repulsions ... More
Rotational Dragging Effect on Statistical Thermodynamics of (2+1)-dimensional Rotating de Sitter SpaceJan 25 2002Brief comments on a plausible holographic relationship between the opposite rotational dragging effect of a (2+1)-dimensional rotating de Sitter space and the non-unitarity of a boundary conformal field theory are given. In addition to the comments, we ... More
Recursive-Cube-of-Rings (RCR) Revisited: Properties and EnhancementMay 09 2013We study recursive-cube-of-rings (RCR), a class of scalable graphs that can potentially provide rich inter-connection network topology for the emerging distributed and parallel computing infrastructure. Through rigorous proof and validating examples, ... More
Fracture of dual crosslink gels with permanent and transient crosslinksJun 29 2016We have carried out systematic fracture experiments in a single edge notch geometry over a range of stretch rates on dual crosslink hydrogels made from polyvinyl alcohol chains chemically crosslinked with glutaraldehyde and physically crosslinked with ... More
Network Coding for $3$s$/n$t Sum-NetworksJan 16 2014A sum-network is a directed acyclic network where each source independently generates one symbol from a given field $\mathbb F$ and each terminal wants to receive the sum $($over $\mathbb F)$ of the source symbols. For sum-networks with two sources or ... More
Barbosa et al. Reply to ``Comment on 'Secure Communication using mesoscopic coherent states', Barbosa et al, Phys Rev Lett 90, 227901", Yuan and Shields, Phys. Rev. Lett. 94, 048901(2005)Feb 10 2005Yuan and Shields claim that our data-encryption protocol is entirely equivalent to a classical stream cipher utilizing no quantum phenomena. Their claim is, indeed, false. Yuan and Shields also claim that schemes similar to the one presented in Phys. ... More
Power-Balanced Orthogonal Space-Time Block CodeJun 20 2008In this paper, we propose two new systematic ways to construct amicable orthogonal designs (AOD), with an aim to facilitate the construction of power-balanced orthogonal spacetime block codes (O-STBC) with favorable practical attributes. We also show ... More
A Delay-Tolerant Potential-Field-Based Network Implementation of an Integrated Navigation SystemAug 23 2016Network controllers (NCs) are devices that are capable of converting dynamic, spatially extended, and functionally specialized modules into a taskable goal-oriented group called networked control system. This paper examines the practical aspects of designing ... More
Blow-up algebras, determinantal ideals, and Dedekind-Mertens-like formulasFeb 11 2015Aug 08 2016We investigate Rees algebras and special fiber rings obtained by blowing up specialized Ferrers ideals. This class of monomial ideals includes strongly stable monomial ideals generated in degree two and edge ideals of prominent classes of graphs. We identify ... More
Polynomial-time algorithms for coding across multiple unicastsApr 25 2006We consider the problem of network coding across multiple unicasts. We give, for wired and wireless networks, efficient polynomial time algorithms for finding optimal network codes within the class of network codes restricted to XOR coding between pairs ... More