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Results for "Y. Li"

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The continuum limit of perturbative coefficients calculated with a large field cutoffSep 14 2003We report MC calculations of perturbative coefficients for lattice scalar field theory in dimensions 1, 2 and 3, where the large field contributions are cutoff. This produces converging (instead of asymptotic) perturbative series. We discuss the statistical ... More
Rough dependence upon initial data exemplified by explicit solutions and the effect of viscosityJun 17 2015In this article, we present some explicit solutions showing rough dependence upon initial data. We also studies viscous effects. An extension of a theorem of Cauchy to the viscous case is also presented.
On the so-called rogue waves in the nonlinear Schrödinger equationNov 02 2015The mechanism of a rogue water wave is still unknown. One popular conjecture is that the Peregrine wave solution of the nonlinear Schr\"odinger equation (NLS) provides a mechanism. A Peregrine wave solution can be obtained by taking the infinite spatial ... More
On the origin of non-Gaussian statistics in hydrodynamic turbulenceAug 29 2005Turbulent flows are notoriously difficult to describe and understand based on first principles. One reason is that turbulence contains highly intermittent bursts of vorticity and strain-rate with highly non-Gaussian statistics. Quantitatively, intermittency ... More
Destructive Read by Wave Interference for ArbitrationMar 16 2017Mar 17 2017With the advent of big data and deep learning, computation power has become a bottleneck for many applications. Network-on-Chip (NoC) has been proposed to enable multiprocessor acceleration for deep learning computation, and efficient arbitration is a ... More
The Spectrum of a linearized 2D Euler operatorJul 17 2001We study the spectral properties of the linearized Euler operator obtained by linearizing the equations of incompressible two dimensional fluid at a steady state with the vorticity that contains only two nonzero complex conjugate Fourier modes. We prove ... More
Different Patterns of Chromospheric Evaporation in a Flaring Region Observed with Hinode/EISNov 20 2010We investigate the chromospheric evaporation in the flare of 2007 January 16 using line profiles observed by the EUV Imaging Spectrometer (EIS) onboard Hinode. Three points at flare ribbons of different magnetic polarities are analyzed in detail. We find ... More
Dynamic Depletion of Vortex Stretching and Non-Blowup of the 3-D Incompressible Euler EquationsFeb 21 2006We study the interplay between the local geometric properties and the non-blowup of the 3D incompressible Euler equations. We consider the interaction of two perturbed antiparallel vortex tubes using Kerr's initial condition \cite{Kerr93}[Phys. Fluids ... More
On symmetric commutator subgroups, braids, links and homotopy groupsFeb 02 2010In this paper, we investigate some applications of commutator subgroups to homotopy groups and geometric groups. In particular, we show that the intersection subgroups of some canonical subgroups in certain link groups modulo their symmetric commutator ... More
Chemical mixing by turbulent convection in the overshooting region below the convective envelope of RGB starsFeb 20 2012Based on the turbulent convection model (TCM), we investigate chemical mixing in the bottom overshooting region of the convective envelope of intermediate-mass stars, focusing on its influence on the formation and extension of blue loops in the Hertzsprung-Russell ... More
Group Velocity of a Probe Light in an Ensemble of Lambda Atoms under Two-Photon ResonanceDec 10 2003Jun 02 2004We study the propagation of a probe light in an ensemble of $\Lambda$-type atoms, utilizing the dynamic symmetry as recently discovered when the atoms are coupled to a classical control field and a quantum probe field {[Sun {\it et al.,} Phys. Rev. Lett. ... More
Global Asymptotics of Stieltjes-Wigert PolynomialsFeb 21 2013Jun 11 2013Asymptotic formulas are derived for the Stieltjes-Wigert polynomials $S_n(z;q)$ in the complex plane as the degree $n$ grows to infinity. One formula holds in any disc centered at the origin, and the other holds outside any smaller disc centered at the ... More
On the Nature of the Extreme-Ultraviolet Late Phase of Solar FlaresJul 22 2014The extreme-ultraviolet (EUV) late phase of solar flares is a second peak of warm coronal emissions (e.g., Fe XVI) for many minutes to a few hours after the GOES soft X-ray peak. It was first observed by the EUV Variability Experiment (EVE) on board the ... More
A Monte Carlo Simulation on Clustering Dynamics of Social AmoebaeJul 18 2011May 13 2013A discrete model for computer simulations of the clustering dynamics of Social Amoebae is presented. This model incorporates the wavelike propagation of extracellular signaling cAMP, the sporadic firing of cells at early stage of aggregation, the signal ... More
Observation of Landau levels of Dirac fermions in graphiteMay 08 2007The low energy electronic excitations in single layer and bilayer graphite (graphene) resemble quantum-relativistic particles also known as Dirac Fermions (DF). They possess an internal degree of freedom, chirality, that leads to unusual Landau Level ... More
Rescattering Effects on Intensity InterferometryMar 29 2005We derive a general formula for the correlation function of two identical particles with the inclusion of multiple elastic scatterings in the medium in which the two particles are produced. This formula involves the propagator of the particle in the medium. ... More
Lattice Vibrational Modes and their Frequency Shifts in Semiconductor NanowiresAug 28 2011We have performed first-principles calculations to study the lattice vibrational modes and their Raman activities in silicon nanowires (SiNWs). Two types of characteristic vibrational modes are examined: high-frequency optical modes and low-frequency ... More
Star cluster formation in cosmological simulations. III. Dynamical and chemical evolutionOct 25 2018In previous papers of this series, we developed a new algorithm for modeling the formation of star clusters in galaxy formation simulations. Here we investigate how dissolution of bound star clusters affects the shape of the cluster mass function and ... More
Probable ratio of the vacuum energy in a Schwarzchild-de Sitter spaceAug 25 2003Feb 07 2004The effects of the generalized uncertainty principle({\bf GUP}) on the cosmological constant problem are discussed in the Schwarzchild-deSitter spacetime, through studying the corrections to its thermodynamics. We derive the correction to the Hawking ... More
Multivariate spacings based on data depth: I. Construction of nonparametric multivariate tolerance regionsJun 18 2008This paper introduces and studies multivariate spacings. The spacings are developed using the order statistics derived from data depth. Specifically, the spacing between two consecutive order statistics is the region which bridges the two order statistics, ... More
Life detection strategy based on infrared vision and ultra-wideband radar data fusionFeb 28 2019The life detection method based on a single type of information source cannot meet the requirement of post-earthquake rescue due to its limitations in different scenes and bad robustness in life detection. This paper proposes a method based on deep neural ... More
Nonexistence of Local Self-Similar Blow-up for the 3D Incompressible Navier-Stokes EquationsMar 06 2006We prove the nonexistence of local self-similar solutions of the three dimensional incompressible Navier-Stokes equations. The local self-similar solutions we consider here are different from the global self-similar solutions. The self-similar scaling ... More
Integral and Series Representations of the Dirac Delta FunctionMar 08 2013Mathematical justifications are given for several integral and series representations of the Dirac delta function which appear in the physics literature. These include integrals of products of Airy functions, and of Coulomb wave functions; they also include ... More
A mathematical model of demand-supply dynamics with collectability and saturation factorsJun 21 2016We introduce a mathematical model on the dynamics of demand and supply incorporating collectability and saturation factors. Our analysis shows that when the fluctuation of the determinants of demand and supply is strong enough, there is chaos in the demand-supply ... More
Modeling the Formation of Globular Cluster Systems in the Virgo ClusterMay 05 2014Nov 03 2014The mass distribution and chemical composition of globular cluster (GC) systems preserve fossil record of the early stages of galaxy formation. The observed distribution of GC colors within massive early-type galaxies in the ACS Virgo Cluster Survey (ACSVCS) ... More
A Resolution of the Sommerfeld ParadoxApr 29 2009Oct 11 2010Sommerfeld paradox roughly says that mathematically Couette linear shear is linearly stable for all Reynolds number, but experimentally arbitrarily small perturbations can induce the transition from the linear shear to turbulence when the Reynolds number ... More
A resolution of the turbulence paradox: numerical implementationMay 19 2009Jul 18 2011Sommerfeld paradox (turbulence paradox) roughly says that mathematically the Couette linear shear flow is linearly stable for all values of the Reynolds number, but experimentally transition from the linear shear to turbulence occurs under perturbations ... More
QFT Treatment of the Klein ParadoxMar 31 2015It is well known that, Klein paradox is one of the most exotic and counterintuitive consequences of quantum theory. Nevertheless, many discussions about the Klein paradox are based upon single-particle Dirac equation in quantum mechanics rather than quantum ... More
Power Spectra of X-ray BinariesApr 22 2002The interpretation of Fourier spectra in the time domain is critically examined. Power density spectra defined and calculated in the time domain are compared with Fourier spectra in the frequency domain for three different types of variability: periodic ... More
Q_6 flavor symmetry model for the extension of the minimal standard model by three right-handed sterile neutrinosDec 26 2011Mar 21 2012The extension of the minimal standard model by three right-handed sterile neutrinos with masses smaller than the electroweak scale (nuMSM) is discussed in a Q_6 flavor symmetry framework. The lightness of the keV sterile neutrino and the near mass degeneracy ... More
The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 2: Vacuum ModificationsMay 12 2015Jun 26 2015Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 ... More
A Markov Chain Approximation of a Segment Description of ChaosFeb 03 2010We test a Markov chain approximation to the segment description (Li, 2007) of chaos (and turbulence) on a tent map, the Minea system, the H\'enon map, and the Lorenz system. For the tent map, we compute the probability transition matrix of the Markov ... More
Schrodinger equation and wave equation on finite graphsJul 22 2012In this paper, we study the schrodinger equation and wave equation with the Dirichlet boundary condition on a connected finite graph. The explicit expressions for solutions are given and the energy conservations are derived. Applications to the corresponding ... More
Turbulent convection model in the overshooting region: II. Theoretical analysisFeb 20 2012Feb 21 2012Turbulent convection models are thought to be good tools to deal with the convective overshooting in the stellar interior. However, they are too complex to be applied in calculations of stellar structure and evolution. In order to understand the physical ... More
Partially dark optical molecule via phase controlAug 02 2016We study the tunable photonic distribution in an optical molecule consisting of two linearly coupled single-mode cavities. With the inter-cavity coupling and two driving fields, the energy levels of the optical-molecule system form a closed cyclic energy-level ... More
Chaotic Spin Dynamics of a Long Nanomagnet Driven by a CurrentMay 01 2008We study the spin dynamics of a long nanomagnet driven by an electrical current. In the case of only DC current, the spin dynamics has a sophisticated bifurcation diagram of attractors. One type of attractors is a weak chaos. On the other hand, in the ... More
Characteristics of convection and overshooting in RGB and AGB starsJul 05 2011Based on the turbulent convection model (TCM) of Li & Yang (2007), we have studied the characteristics of turbulent convection in the envelopes of 2 and 5M stars at the RGB and AGB phases. The TCM has been applied successfully in the whole convective ... More
Dynamic Stability of the 3D Axi-symmetric Navier-Stokes Equations with SwirlAug 12 2006In this paper, we study the dynamic stability of the 3D axisymmetric Navier-Stokes Equations with swirl. To this purpose, we propose a new one-dimensional (1D) model which approximates the Navier-Stokes equations along the symmetry axis. An important ... More
Computing Nearly Singular Solutions Using Pseudo-Spectral MethodsJan 12 2007In this paper, we investigate the performance of pseudo-spectral methods in computing nearly singular solutions of fluid dynamics equations. We consider two different ways of removing the aliasing errors in a pseudo-spectral method. The first one is the ... More
Numerical Study of Nearly Singular Solutions of the 3-D Incompressible Euler EquationsAug 11 2006In this paper, we perform a careful numerical study of nearly singular solutions of the 3D incompressible Euler equations with smooth initial data. We consider the interaction of two perturbed antiparallel vortex tubes which was previously investigated ... More
Quantum Memory Based on $Λ$-Atoms Ensemble with Two-Photon Resonance EITFeb 24 2004We study the $\Lambda$-atoms ensemble based quantum memory for the storage of the quantum information carried by a probe light field. Two atomic Rabi transitions of the ensemble are coupled to the quantum probe field and classical control field respectively ... More
Tunability of electronic and optical properties of the Ba-Zr-S system via dimensional reductionMar 04 2018Aug 24 2018Transition metal sulfide perovskites offer lower band gaps and greater tunability than oxides, along with other desirable properties for applications. Here we explore dimensional reduction as a tuning strategy using the Ruddlesden-Popper phases in the ... More
Algebras associated with Blaschke products of type {\it G}Dec 14 1995Let $\Omega$ and $\Omega_{\fin}$ be the sets of all interpolating Blaschke products of type $G$ and of finite type $G$, respectively. Let $E$ and $E_{\fin}$ be the Douglas algebras generated by $H^\infty$ together with the complex conjugates of elements ... More
Matter Effects in Active-Sterile Solar Neutrino OscillationsOct 30 2009Dec 21 2009The matter effects for solar neutrino oscillations are studied in a general scheme with an arbitrary number of sterile neutrinos, without any constraint on the mixing, assuming only a realistic hierarchy of neutrino squared-mass differences in which the ... More
On the Dynamics of Navier-Stokes and Euler EquationsNov 10 2006This is a rather comprehensive study on the dynamics of Navier-Stokes and Euler equations via a combination of analysis and numerics. We focus upon two main aspects: (a). zero viscosity limit of the spectra of linear Navier-Stokes operator, (b). heteroclinics ... More
Plasma Brightenings in a Failed Solar Filament EruptionFeb 16 2017Failed filament eruptions are solar eruptions that are not associated with coronal mass ejections. In a failed filament eruption, the filament materials usually show some ascending and falling motions as well as generate bright EUV emissions. Here we ... More
Interaction and Eruption of Two Filaments Observed by Hinode, SOHO, and STEREONov 17 2011Nov 21 2011We investigate the interaction between two filaments and the subsequent filament eruption event observed from different view angles by Hinode, the Solar and Heliospheric Observatory (SOHO), and the Solar Terrestrial Relations Observatory (STEREO). In ... More
Enumeration of Rota-Baxter WordsFeb 21 2006Jun 26 2006In this paper, we prove results on enumerations of sets of Rota-Baxter words in a finite number of generators and a finite number of unary operators. Rota-Baxter words are words formed by concatenating generators and images of words under Rota-Baxter ... More
Average CsI neutron density distribution from COHERENT dataOct 07 2017Jan 29 2018Using the coherent elastic neutrino-nucleus scattering data of the COHERENT experiment, we determine for the first time the average neutron rms radius of $^{133}\text{Cs}$ and $^{127}\text{I}$. We obtain the practically model-independent value $ R_{n} ... More
Galaxy Properties Derived with Spectral Energy Distribution Fitting in the Hawaii-Hubble Deep Field-NorthSep 30 2018We compile multi-wavelength data from ultraviolet to infrared (IR) bands as well as redshift and source-type information for a large sample of 178,341 sources in the Hawaii-Hubble Deep Field-North field. A total of 145,635 sources among the full sample ... More
Magnetic Coupling in Ferromagnetic Semiconductor GaMnAs/AlGaMnAs Bilayer DevicesJan 24 2015We carefully investigated the ferromagnetic coupling in the as-grown and annealed ferromagnetic semiconductor GaMnAs/AlGaMnAs bilayer devices. We observed that the magnetic interaction between the two layers strongly affects the magnetoresistance of the ... More
Penguin Enhancement and $B\to Kπ$ decays in perturbative QCDApr 18 2000We compute branching ratios of $B\to K\pi$ decays in the framework of perturbative QCD factorization theorem. Decay amplitudes are classified into the topologies of tree, penguin and annihilation, all of which contain both factorizable and nonfactorizable ... More
A Novel PQCD Approach in Charmless B-meson DecaysJan 12 2002Sep 12 2002We discuss a novel pertubative QCD approach on the exclusive non-leptonic two body B-meson decays. We briefly review its ingredients and some important theoretical issues on the factorization approaches. We show numerical results which is compatible with ... More
Localization of Relative-Position of Two Atoms Induced by Spontaneous EmissionJan 16 2005We revisit the back-action of emitted photons on the motion of the relative position of two cold atoms. We show that photon recoil resulting from the spontaneous emission can induce the localization of the relative position of the two atoms through the ... More
Cosmic Reionization On Computers. Ultraviolet Continuum Slopes and Dust Opacities in High Redshift GalaxiesJan 04 2016Feb 25 2016We compare the properties of stellar populations of model galaxies from the Cosmic Reionization On Computers (CROC) project with the exiting UV and IR data. Since CROC simulations do not follow cosmic dust directly, we adopt two variants of the dust-follows-metals ... More
Propagation of field disturbances in the Yang-Mills theoryJul 10 2008The propagation of field disturbances is examined in the context of the effective Yang-Mills Lagrangian, which is intended to be applied to QCD systems. It is shown that birefringence phenomena can occur in such systems provided some restrictive conditions, ... More
The Coupled Cluster Method Applied to Quantum Magnets: A New LPSUB$m$ Approximation Scheme for Lattice ModelsOct 11 2010A new approximation hierarchy, called the LPSUB$m$ scheme, is described for the coupled cluster method (CCM). It is applicable to systems defined on a regular spatial lattice. We then apply it to two well-studied prototypical (spin-1/2 Heisenberg antiferromagnetic) ... More
Heating and Dynamics of Two Flare Loop Systems Observed by AIA and EISDec 18 2013We investigate heating and evolution of flare loops in a C4.7 two-ribbon flare on 2011 February 13. From SDO/AIA imaging observations, we can identify two sets of loops. Hinode/EIS spectroscopic observations reveal blueshifts at the feet of both sets ... More
New examples on spaces of negative sectional curvature satisfying Ma-Trudinger-Wang conditionsNov 20 2009Dec 04 2009In this paper, we study the Ma-Trudinger-Wang (MTW) conditions for cost functions $c$ which are of the form $c=l\circ d$, where $d$ is a Riemannian distance function with constant sectional curvature. In this case, the MTW conditions are equivalent to ... More
Imaging observations of chromospheric evaporation in a circular-ribbon flareNov 28 2018In this paper, we report our multiwavelength imaging observations of chromospheric evaporation in a C5.5 circular-ribbon flare (CRF) on 2014 August 24. The flare was observed by the Atmospheric Imaging Assembly (AIA) on board the \textit{Solar Dynamics ... More
Absence of magnetic thermal conductivity in the quantum spin liquid candidate YbMgGaO4Nov 23 2016We present the ultra-low-temperature specific heat and thermal conductivity measurements on the single crystals of YbMgGaO$_4$, which was recently argued to be a promising candidate for quantum spin liquid (QSL). In the zero magnetic field, a large magnetic ... More
Spectroscopic and Photometric Observations of Unidentified Ultraviolate Variable Objects in GUVV-2 CatalogMar 30 2011An NUV-optical diagram made for sources from the secend Galaxy Evolution Explorer (GALEX) Ultraviolet Variability (GUVV-2) Catalog provide us a method to tentatively classify the unknown GUVV2 sources by their NUV-optical magnitudes. On the purpose of ... More
Optical unidirectional amplification in a three-mode optomechanical systemMay 24 2017Jul 28 2017We study the directional amplification of an optical probe field in a three-mode optomechanical system, where the mechanical resonator interacts with two linearly-coupled optical cavities and the cavities are driven by strong optical pump fields. The ... More
Bosonization for 2D Interacting Fermion Systems: Non-Fermi Liquid BehaviorJan 11 1994Non-Fermi liquid behavior is found for the first time in a two-dimensional (2D) system with non-singular interactions using Haldane's bosonization scheme. The bosonized system is solved exactly by a generalized Bogoliubov transformation. The fermion momentum ... More
Impulsive cylindrical gravitational wave: one possible radiative form emitted from cosmic strings and corresponding electromagnetic responseMar 28 2014May 04 2014The cosmic strings(CSs) may be one important source of gravitational waves(GWs), and it has been intensively studied due to its special properties such as the cylindrical symmetry. The CSs would generate not only usual continuous GW, but also impulsive ... More
Coronal magnetic topology and the production of solar impulsive energetic electronsJul 17 2013We investigate two candidate solar sources or active regions (ARs) in association with a solar impulsive energetic electron (SIEE) event on 2002 October 20. The solar particle release (SPR) times of SIEEs are derived by using their velocity dispersion ... More
The Butterfly Decomposition of Plane TreesNov 02 2005We introduce the notion of doubly rooted plane trees and give a decomposition of these trees, called the butterfly decomposition which turns out to have many applications. From the butterfly decomposition we obtain a one-to-one correspondence between ... More
Spin wave based quantum storage of electronic spin with a ring array of nuclear spinsSep 18 2004Apr 14 2006We propose a solid state based protocol to implement the universal quantum storage for electronic spin qubit. The quantum memory in this scheme is the spin wave excitation in the ring array of nuclei in a quantum dot. We show that the quantum information ... More
Adiabatic passage of collective excitations in atomic ensemblesJun 27 2003We describe a theoretical scheme that allows for transfer of quantum states of atomic collective excitation between two macroscopic atomic ensembles localized in two spatially-separated domains. The conception is based on the occurrence of double-exciton ... More
Robust Multiple-Range Coherent Quantum State TransferDec 07 2015We propose a multiple-range quantum communication channel to realize coherent two-way quantum state transport with high fidelity. In our scheme, an information carrier (a qubit) and its remote partner are both adiabatically coupled to the same data bus, ... More
Tracking Back the Solar Wind to its Photospheric Footpoints from Wind Observations -- A Statistical StudyFeb 25 2014It is of great importance to track the solar wind back to its photospheric source region and identify the related current sheets; this will provide key information for investigating the origin and predictions of the solar wind. We report a statistical ... More
Merging Strangeon StarsOct 13 2017Mar 13 2018The state of supranuclear matter in compact star remains puzzling, and it is argued that pulsars could be strangeon stars. What if binary strangeon stars merge? This kind of merger could result in the formation of a hyper-massive strangeon star, accompanied ... More
On Symplectic and Multisymplectic Srtuctures and their Discrete Versions in Lagrangian FormalismApr 06 2001Aug 13 2001We introduce the Euler-Lagrange cohomology to study the symplectic and multisymplectic structures and their preserving properties in finite and infinite dimensional Lagrangian systems respectively. We also explore their certain difference discrete counterparts ... More
Nonlinear optomechanics with gain and loss: amplifying higher-order sideband and group delayFeb 17 2016Aug 07 2016We study the nonlinear optomechanically-induced transparency (OMIT) with gain and loss. We find that (i) for a single active cavity, significant enhancement can be achieved for the higher-order sidebands, including the transmission rate and the group ... More
The minimum magnetic field of millisecond pulsars calculated according to accretion: application to the X-ray neutron star SAX J1808.4-3658 in a low-mass X-ray binaryAug 02 2018Based on the model of the accretion-induced magnetic field decay of a neutron star (NS), millisecond pulsars (MSPs) will obtain their minimum magnetic field when the NS magnetosphere radius shrinks to the stellar surface during the binary accretion phase. ... More
Many-body approach to the dynamics of batch learningSep 01 1999Using the cavity method and diagrammatic methods, we model the dynamics of batch learning of restricted sets of examples, widely applicable to general learning cost functions, and fully taking into account the temporal correlations introduced by the recycling ... More
A Note on Symplectic AlgorithmsApr 06 2001Aug 09 2001We present the symplectic algorithm in the Lagrangian formalism for the Hamiltonian systems by virtue of the noncommutative differential calculus with respect to the discrete time and the Euler--Lagrange cohomological concepts. We also show that the trapezoidal ... More
Assessment of Transverse Instabilities in Proton Driven Hollow Plasma Wakefield AccelerationMay 08 2018Hollow plasma has been introduced into the proton-driven plasma wakefield accelerators to overcome the issue of beam quality degradation caused by the nonlinear transverse wakefields varying in radius and time in uniform plasma. It has been demonstrated ... More
A Decision-Theoretic Approach to Resource Allocation in Wireless Multimedia NetworksJun 27 2000The allocation of scarce spectral resources to support as many user applications as possible while maintaining reasonable quality of service is a fundamental problem in wireless communication. We argue that the problem is best formulated in terms of decision ... More
Three-way noiseless signal splitting in a parametric amplifier with quantum correlationDec 04 2015We demonstrate that a phase-insensitive parametric amplifier, coupled to a quantum correlated source, can be used as a quantum information tap for noiseless three-way signal splitting. We find that the output signals are amplified noiselessly in two of ... More
Gamma-Ray Burst Environments and ProgenitorsApr 29 1999May 20 1999Likely progenitors for the GRBs (gamma-ray bursts) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the ISM (interstellar ... More
Scanning Tunneling Spectroscopy of Graphene on GraphiteMar 28 2008Jun 11 2009We report low temperature high magnetic field scanning tunneling microscopy and spectroscopy of graphene flakes on graphite that exhibit the structural and electronic properties of graphene decoupled from the substrate. Pronounced peaks in the tunneling ... More
Complete phase diagram of the spin-1/2 $J_{1}$-$J_{2}$-$J_{3}$ model (with $J_{3}=J_{2}$) on the honeycomb latticeFeb 28 2012We use the coupled cluster method to investigate the ground-state (GS) properties of the frustrated spin-1/2 $J_{1}$-$J_{2}$-$J_{3}$ model on the honeycomb lattice, with nearest-neighbor exchange coupling $J_1$ plus next-nearest-neighbor ($J_2$) and next-next-nearest-neighbor ... More
A frustrated quantum spin-${\boldmath s}$ model on the Union Jack lattice with spins ${\boldmath s>1/2}$Oct 25 2010The zero-temperature phase diagrams of a two-dimensional frustrated quantum antiferromagnetic system, namely the Union Jack model, are studied using the coupled cluster method (CCM) for the two cases when the lattice spins have spin quantum number $s=1$ ... More
Bilinear forms on Green rings of finite dimensional Hopf algebrasDec 17 2015Apr 01 2016In this paper, we study the Green ring and the stable Green ring of a Hopf algebra $H$ by means of bilinear forms. We show that the Green ring of a Hopf algebra of finite representation type is a Frobenius algebra over $\mathbb{Z}$ with a dual basis associated ... More
Global Regularity of the 3D Axi-symmetric Navier-Stokes Equations with Anisotropic DataJan 22 2009Jan 24 2009In this paper, we study the 3D axi-symmetric Navier-Stokes Equations with swirl. We prove the global regularity of the 3D Navier-Stokes equations for a family of large anisotropic initial data. Moreover, we obtain a global bound of the solution in terms ... More
Short term unpredictability of high Reynolds number turbulence --- rough dependence on initial dataFeb 09 2017Short term unpredictability is discovered numerically for high Reynolds number fluid flows under periodic boundary conditions. Furthermore, the abundance of the short term unpredictability is also discovered. These discoveries support our theory that ... More
Bishop and Laplacian comparison theorems on Sasakian manifoldsOct 20 2013Oct 22 2013We prove a Bishop volume comparison theorem and a Laplacian comparison theorem for a natural sub-Riemannian structure defined on Sasakian manifolds. This generalizes the earlier work for the three dimensional case.
Quasiconformal maps with bilipschitz or identity boundary values in Banach spacesSep 25 2012Mar 16 2013Suppose that $E$ and $E'$ denote real Banach spaces with dimension at least 2 and that $D\varsubsetneq E$ and $D'\varsubsetneq E'$ are uniform domains with homogeneously dense boundaries. We consider the class of all $\varphi$-FQC (freely $\varphi$-quasiconformal) ... More
On John domains in Banach spacesSep 24 2013We study the stability of John domains in Banach spaces under removal of a countable set of points. In particular, we prove that the class of John domains is stable in the sense that removing a certain type of closed countable set from the domain yields ... More
On recent data of branching ratios for psi(2S)-->J/psi pi pi and psi(2S)-->J/psi etaDec 22 1998Jan 06 1999Recent data on branching ratios for \psi(2S) decays to J/\psi\pi^+\pi^-, J/\psi\pi^0\pi^0 and J/\psi\eta are reviewed. An alternative treatment of data is proposed to get rid of the logical inconsistency which occurs in original computational procedure. ... More
A frustrated honeycomb-bilayer Heisenberg antiferromagnet: The spin-$\frac{1}{2}$ $J_{1}$--$J_{2}$--$J_{1}^{\perp}$ modelNov 10 2016We use the coupled cluster method to study the zero-temperature quantum phase diagram of the spin-$\frac{1}{2}$ $J_{1}$--$J_{2}$--$J_{1}^{\perp}$ model on the honeycomb bilayer lattice. In each layer we include both nearest-neighbor and frustrating next-nearest-neighbor ... More
Exploring the locally low dimensional structure in solving random elliptic PDEsJul 03 2016We propose a stochastic multiscale finite element method (StoMsFEM) to solve random elliptic partial differential equations with a high stochastic dimension. The key idea is to simultaneously upscale the stochastic solutions in the physical space for ... More
Ground-state phase structure of the spin-$\frac{1}{2}$ anisotropic planar pyrochloreApr 30 2015Aug 13 2015We study the zero-temperature ground-state (GS) properties of the spin-$\frac{1}{2}$ anisotropic planar pyrochlore, using the coupled cluster method (CCM) implemented to high orders of approximation. The system comprises a $J_{1}$--$J_{2}$ model on the ... More
Magnetic order in spin-1 and spin-3/2 interpolating square-triangle Heisenberg antiferromagnetsNov 30 2011Using the coupled cluster method we investigate spin-$s$ $J_{1}$-$J_{2}'$ Heisenberg antiferromagnets (HAFs) on an infinite, anisotropic, triangular lattice when the spin quantum number $s=1$ or $s=3/2$. With respect to a square-lattice geometry the model ... More
Large-$s$ expansions for the low-energy parameters of the honeycomb-lattice Heisenberg antiferromagnet with spin quantum number $s$Dec 03 2015Jan 30 2016The coupled cluster method (CCM) is employed to very high orders of approximation to study the ground-state (GS) properties of the spin-$s$ Heisenberg antiferromagnet (with isotropic interactions, all of equal strength, between nearest-neighbour pairs ... More
Ground-state phases of the spin-1 $J_{1}$--$J_{2}$ Heisenberg antiferromagnet on the honeycomb latticeFeb 29 2016Jun 15 2016We study the zero-temperature quantum phase diagram of a spin-1 Heisenberg antiferromagnet on the honeycomb lattice with both nearest-neighbor exchange coupling $J_{1}>0$ and frustrating next-nearest-neighbor coupling $J_{2} \equiv \kappa J_{1} > 0$, ... More
Minimum-Energy Mobile Wireless Networks RevisitedSep 05 2002We propose a protocol that, given a communication network, computes a subnetwork such that, for every pair $(u,v)$ of nodes connected in the original network, there is a minimum-energy path between $u$ and $v$ in the subnetwork (where a minimum-energy ... More
Nuclear Star Clusters in Cosmological SimulationsApr 25 2018Jul 23 2018We investigate the possible connection between the most massive globular clusters, such as $\omega$ Cen and M54, and nuclear star clusters of dwarf galaxies that exhibit similar spreads in age and metallicity. We examine galactic nuclei in cosmological ... More
Coherent structure of Alice-Bob modified Korteweg de-Vries EquationJun 25 2017To describe two-place events, Alice-Bob systems have been established by means of the shifted parity and delayed time reversal in Ref. [1]. In this paper, we mainly study exact solutions of the integrable Alice-Bob modified Korteweg de-Vries (AB-mKdV) ... More