Results for "Y. Bai"

total 40884took 0.13s
The Performance of CRTNT Fluorescence Light Detector for Sub-EeV Cosmic Ray ObservationFeb 22 2006Cosmic Ray Tau Neutrino Telescopes (CRTNT) using for sub-EeV cosmic ray measurement is discussed. Performances of a stereoscope configuration with a tower of those telescopes plus two side-triggers are studied. This is done by using a detailed detector ... More
Another approach to Hom-Lie bialgebras via Manin triplesMar 24 2019In this paper, we study Hom-Lie bialgebras by a new notion of the dual representation of a representation of a Hom-Lie algebra. Motivated by the essential connection between Lie bialgebras and Manin triples, we introduce the notion of a Hom-Lie bialgebra ... More
Magic high-order harmonics from a quasi-one-dimensional hexagonal solidAug 20 2019High-order harmonic generation (HHG) from atoms is a coherent light source that opens up attosecond physics, but it is the application of HHG to solids that brings much of excitement for the last decade. Here we report a completely new kind of harmonics ... More
Switching ferromagnetic spins by an ultrafast laser pulse: Emergence of giant optical spin-orbit torqueSep 19 2016Faster magnetic recording technology is indispensable to massive data storage and big data sciences. {All-optical spin switching offers a possible solution}, but at present it is limited to a handful of expensive and complex rare-earth ferrimagnets. The ... More
Manifestation of intra-atomic 5d6s-4f exchange coupling in photoexcited gadoliniumDec 16 2017Intra-atomic exchange couplings (IEC) between $5d6s$ and $4f$ electrons are ubiquitous in rare-earth metals and play a critical role in spin dynamics. However, detecting them in real time domain has been difficult. Here we show the direct evidence of ... More
Is perpendicular magnetic anisotropy essential to all-optical ultrafast spin reversal in ferromagnets?Sep 25 2017All-optical spin reversal presents a new opportunity for spin manipulations, free of a magnetic field. Most of all-optical-spin-reversal ferromagnets are found to have a perpendicular magnetic anisotropy (PMA), but it has been unknown whether PMA is necessary ... More
Some Mathematical Aspects of Price OptimisationMay 19 2016Calculation of an optimal tariff is a principal challenge for pricing actuaries. In this contribution we are concerned with the renewal insurance business discussing various mathematical aspects of calculation of an optimal renewal tariff. Our motivation ... More
A new and simple model for magneto-optics uncovers an unexpected spin switchingMay 16 2016In magneto-optics the spin angular momentum $S_z$ of a sample is indirectly probed by the rotation angle and ellipticity, which are mainly determined by the off-diagonal susceptibility $\chi^{(1)}_{xy}$. A direct and analytic relation between $S_z$ and ... More
Ultrafast reduction of exchange splitting in ferromagnetic nickelNov 10 2016A decade ago Rhie \et (Phys. Rev. Lett. {\bf 90}, 247201 (2003)) reported that when ferromagnetic nickel is subject to an intense ultrashort laser pulse, its exchange splitting is reduced quickly. But to simulate such reduction remains a big challenge. ... More
Giant magnetoelectric effect under high bias fields in cylindrical bilayered Ni-PZT compositesAug 31 2007For conventional plate and disc layered magnetoelectric (ME) composites, the ME effect appeared under low bias magnetic fields, which caused by line magnetostriction. In this paper, we present a new structure ME composites, cylindrical bilayered composites. ... More
Particle acceleration and synchrotron self-Compton emission in blazar jets I : an application to the quiescent emissionFeb 21 2019There are still some important unanswered questions about the detailed particle acceleration and escape occurring during the quiescent epoches. As a result, the particle distribution that is adopted in the blazar quiescent spectral model have numerous ... More
Shape demagnetization effect on layered magnetoelectric compositesAug 30 2007Magnetoelectric (ME) voltage coefficient was always considered independent on in-plane shape of plate layered magnetostrictive-piezoelectric composites due to the oversimplification in ME theoretical models. In this article, we present that in fact the ... More
Ni-PZT-Ni Trilayered Magnetoelectric composites Synthesized by Electro-depositionAug 30 2007We report the high strength of magnetoelectric (ME) coupling of trilayered composites prepared by electro-deposition. The ME coupling of Ni-lead zirconate titanate (PZT)-Ni trilayered structure was measured ranged from1 kHz to 120 kHz. The trilayered ... More
Magnetoelectric Effect in Ni-PZT-Ni Cylindrical Layered Composite Synthesized by Electro-depositionAug 30 2007The magnetoelectric (ME) coupling of cylindrical trilayered composite was studied in this paper. The Ni-lead zirconate titanate (PZT)-Ni trilayered cylindrical composite was synthesized by electro-deposition. The maximum ME voltage coefficient of cylindrical ... More
First-principles and model simulation of all-optical spin reversalOct 05 2017All-optical spin switching is a potential trailblazer for information storage and communication at an unprecedented fast rate and free of magnetic fields. However, the current wisdom is largely based on semiempirical models of effective magnetic fields ... More
Hand in Hand Evolution of b-relaxation and Boson Peak in Metallic GlassesJul 02 2015Boson peak and beta-relaxation are two intrinsic and markedly different dynamic modes of glasses, and their structural origins are long-standing issues. Through tuning atomic packing of a model metallic glass with microalloying of different types of elements, ... More
Quasi-particle random phase approximation with quasi-particle-vibration coupling: application to the Gamow-Teller response of the superfluid nucleus $^{120}$SnSep 08 2016We propose a self-consistent quasi-particle random phase approximation (QRPA) plus quasi-particle-vibration coupling (QPVC) model with Skyrme interactions to describe the width and the line shape of giant resonances in open-shell nuclei, in which the ... More
Fiber-based Radio Frequency Dissemination for Branching Networks with Passive Phase Noise CancellationJan 14 2015We demonstrate a new fiber-based radio frequency dissemination scheme for branching networks. Without any phase controls on RF signals or usages of active feedback locking components, the highly stable reference frequency signal can be delivered to several ... More
Generating high-order optical and spin harmonics from ferromagnetic monolayersSep 03 2018High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed ... More
Impurity scattering and Friedel oscillations in mono-layer black phosphorusMar 15 2016Mar 17 2016We study the effect of impurity scattering effect in black phosphorurene (BP) in this work. For single impurity, we calculate impurity induced local density of states (LDOS) in momentum space numerically based on tight-binding Hamiltonian. In real space, ... More
Fiber Based Multiple-Access Optical Frequency DisseminationMay 15 2013Jun 07 2013We demonstrate a fiber based multiple-access optical frequency dissemination scheme. Without using any additional laser sources, we reproduce the stable disseminated frequency at an arbitrary point of fiber link. Relative frequency stability of 3E10^{-16}/s ... More
Square Kilometer Array Telescope - Precision Reference Frequency Synchronisation via 1f-2f DisseminationApr 22 2015The Square Kilometer Array (SKA) is an international effort to build the world's largest radio telescope, with one square kilometer collecting area. Besides its ambitious scientific objectives, such as probing the cosmic dawn and cradle of life, SKA also ... More
Understanding all-optical spin switching: Comparison between experiment and theoryAug 21 2018Oct 08 2018Information technology depends on how one can control and manipulate signals accurately and quickly. Transistors are at the core of modern technology and are based on electron charges. But as the device dimension shrinks, heating becomes a major problem. ... More
Coexistence of two superconducting phases in Ca1-xLaxFe2As2Sep 17 2013Single crystals of Ca1-xLaxFe2As2 for x ranging from 0 to 0.25 have been grown and characterized by structural, transport and magnetic measurements. Coexistence of two superconducting phases is observed, in which the low superconducting transition temperature ... More
Superintermolecular orbitals in the C$_{60}$/pentacene complexNov 10 2016We report a group of unusually big molecular orbitals in the C60/pentacene complex. Our first-principles density functional calculation shows that these orbitals are very delocalized and cover both C60 and pentacene, which we call superintermolecular ... More
All-optical spin switching: A new frontier in femtomagnetism -- A short review and a simple theorySep 28 2016Oct 14 2016Using an ultrafast laser pulse to manipulate the spin degree of freedom has broad technological appeal. It allows one to control the spin dynamics on a femtosecond time scale. The discipline, commonly called femtomagnetism, started with the pioneering ... More
Searching for high-$K$ isomers in the proton-rich $A\sim80$ mass regionMar 24 2016Configuration-constrained potential-energy-surface calculations have been performed to investigate the $K$ isomerism in the proton-rich $A\sim80$ mass region. An abundance of high-$K$ states are predicted. These high-$K$ states arise from two and four-quasi-particle ... More
Laser-induced ultrafast transport and demagnetization at the earliest time: First-principles and real-time investigationOct 06 2018Here we carry out a first-principles time-dependent calculation to investigate how fast electrons actually move under laser excitation and how large the electron transport affects demagnetization on the shortest time scale. To take into account the transport ... More
Magnetic spin moment reduction in photoexcited ferromagnets through exchange interaction quenching: Beyond the rigid band approximationMay 08 2015The exchange interaction among electrons is one of the most fundamental quantum mechanical interactions in nature and underlies any magnetic phenomena from ferromagnetic ordering to magnetic storage. The current technology is built upon a thermal or magnetic ... More
Neutrino Lighthouse at Sagittarius A*Jul 08 2014We investigate whether a subset of high-energy events observed by IceCube may be due to neutrinos from Sagittarius A*. We check both spatial and temporal coincidences of IceCube events with other transient activities of Sagittarius A*. Among the seven ... More
Upper Critical Fields and Anisotropy of Ca1-xLaxFe2As2 Single CrystalsAug 27 2013Superconductivity of Ca1-xLaxFe2As2 single crystals with various doping level were investigated via electromagnetic measurements for out-plane (H//c) and in-plane (H//ab) directions. Obvious double superconducting transitions, which can survive in magnetic ... More
High sensitivity microwave detection using a magnetic tunnel junction in the absence of an external applied magnetic fieldApr 14 2015In the absence of any external applied magnetic field, we have found that a magnetic tunnel junction (MTJ) can produce a significant output direct voltage under microwave radiation at frequencies, which are far from the ferromagnetic resonance condition, ... More
M dwarf Stars - The By-Product of X-Ray Selected AGN CandidatesJan 06 2012X-ray loud M dwarfs are a major source of by-product (contamination) in the X-ray band of the multiwavelength quasar survey (MWQS). As a by-product, the low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16 sources are taken for ... More
Long distance part of $ε_K$ from lattice QCDNov 20 2016We demonstrate the lattice QCD calculation of the long distance contribution to $\epsilon_K$. Due to the singular, short-distance structure of $\epsilon_K$, we must perform a short-distance subtraction and introduce a corresponding low-energy constant ... More
Gelfand-Kirillov Dimensions of the Z-graded Oscillator Representations of $\mathfrak{o}(n,\mathbb{C})$ and $\mathfrak{sp}(2n,\mathbb{C})$Jan 20 2015Jul 30 2017In this paper, we compute the Gelfand-Kirillov dimensions for the infinite-dimensional explicit irreducible $\mathfrak{o}(n, \mathbb{C})$-modules and $\mathfrak{sp}(2n, \mathbb{C})$-modules that appeared in the $\mathbb{Z}$-graded oscillator generalizations ... More
Estimation of Change-point ModelsMay 01 2018May 08 2018We consider the testing and estimation of change-points, locations where the distribution abruptly changes, in a sequence of observations. Motivated by this problem, in this contribution we first investigate the extremes of Gaussian fields with trend ... More
Extremes of multifractional Brownian motionNov 15 2017Mar 30 2019Let $B_{H}(t), t\geq [0,T], T\in(0,\infty)$ be the standard Multifractional Brownian Motion(mBm), in this contribution we are concerned with the exact asymptotics of \begin{eqnarray*} \mathbb{P}\left\{\sup_{t\in[0,T]}B_{H}(t)>u\right\} \end{eqnarray*} ... More
Parisian ruin of Brownian motion risk model over an infinite-time horizonFeb 20 2017Let $B(t), t\in \mathbb{R}$ be a standard Brownian motion. In this paper, we derive the exact asymptotics of the probability of Parisian ruin on infinite time horizon for the following risk process \begin{align}\label{Rudef} R_u^{\delta}(t)=e^{\delta ... More
Extremes of $α(t)$-Locally stationary Gaussian processes with non-constant variancesJun 22 2016Aug 21 2016With motivation from K. D\c{e}bicki and P. Kisowski (2007), in this paper we derive the exact tail asymptotics of $\alpha(t)$-locally stationary Gaussian processes with non-constant variance functions. We show that some certain variance functions lead ... More
Mini Little Higgs and Dark MatterJan 10 2008Aug 25 2008We construct a little Higgs model with the most minimal extension of the standard model gauge group by an extra U(1) gauge symmetry. For specific charge assignments of scalars, an approximate U(3) global symmetry appears in the cutoff-squared scalar mass ... More
A note on hypergraph coloringsAug 12 2018Let $t\geqslant 2$ and $s\geqslant 1$ be two integers. Define a $(t,s)$-coloring of a hypergraph to be a coloring of its vertices using $t$ colors such that each color appears on each edge at least $s$ times. In this note, we provide a sufficient condition ... More
Rejuvenation of metallic glasses under high pressureSep 26 2016Modulating energy states of metallic glasses (MGs) is significant in understanding the nature of glasses and control their properties. In this study, we show that rejuvenation in enthalpy can be achieved and preserved in bulk MGs by using high pressure ... More
Imaging superatomic molecular orbitals in a ${\bf C_{60}}$ molecule through four 800-nm photonsApr 27 2015Superatomic molecular orbitals (SAMO) in C60 are ideal building blocks for functional nanostructures. However, imaging them spatially in the gas phase has been unsuccessful. It is found experimentally that if C60 is excited by an 800-nm laser, the photoelectron ... More
The anisotropic flow coefficients $v_2$ and $v_4$ in Au+Au collisions at RHICJan 23 2007We present measurements by STAR of the anisotropic flow coefficients $v_2$ and $v_4$ as a function of particle-type, centrality, transverse momentum and pseudorapidity in Au+Au collisions at RHIC.
Particle Motion in Generalized Dirac's Monopoles of dimension 2k+1Nov 16 2015Nov 17 2015By using Meng's idea in his generalization of the classical MICZ-Kepler problem, we obtained the equations of motion of a charged particle in the field of generalized Dirac monopole in odd dimensional Euclidean spaces. The main result is that for every ... More
$K_L$ - $K_S$ mass difference computed with a 171 MeV pion massNov 12 2014In this work, we used a $32^3 \times 64 \times 32$, 2+1 flavor domain wall lattice with Iwasaki+DSDR gauge action. The pion mass is 171 MeV and the kaon mass is 492 MeV. We implement the Glashow-Iliopoulos-Maiani (GIM) cancellation using charm quark masses ... More
Gelfand-Kirillov dimensions of the $Z^2$-graded oscillator representations of sl(n)Jan 20 2015Nov 18 2015We find an exact formula of Gelfand-Kirillov dimensions for the infinite-dimensional explicit irreducible sl(n, F)-modules that appeared in the Z^2-graded oscillator generalizations of the classical theorem on harmonic polynomials established by Luo and ... More
Bijective 1-cocycles and classification of 3-dimensional Left-symmetric AlgebrasOct 13 2007Left-symmetric algebras have close relations with many important fields in mathematics and mathematical physics. Their classification is very complicated due to the nonassociativity. In this paper, we re-study the correspondence between left-symmetric ... More
Left-symmetric Algebras From Linear FunctionsJun 16 2004In this paper, some left-symmetric algebras are constructed from linear functions. They include a kind of simple left-symmetric algebras and some examples appearing in mathematical physics. Their complete classification is also given, which shows that ... More
Double constructions of Frobenius algebras, Connes cocycles and their dualityAug 25 2008Aug 15 2010We construct an associative algebra with a decomposition into the direct sum of the underlying vector spaces of another associative algebra and its dual space such that both of them are subalgebras and the natural symmetric bilinear form is invariant ... More
A Population of Radio-loud Narrow Line Seyfert 1 Galaxies with Blazar-like Properties?Jun 24 2008(abridged) We present a comprehensive study of a sample of 23 genuine radio-loud NLS1 galaxies which have the radio-loudness parameters greater than 100. The radio sources of the sample are ubiquitously compact. A significant fraction of these objects ... More
Pairing transitions in the finite-temperature relativistic Hartree-Bogoliubov theoryJun 20 2013Jan 20 2014We formulate the finite-temperature relativistic Hartree-Bogoliubov theory for spherical nuclei based on a point-coupling functional, with the Gogny or separable pairing force. Using the functional PC-PK1, the framework is applied to the study of pairing ... More
Search for Intra-day Optical Variability in $γ$-ray--loud Blazars S5 0716+714 and 3C 273Jun 15 2019Aug 07 2019We present the photometric observations of blazars S5 0716+714 and 3C 273 with high temporal resolution (30--60s) in the $I$ or $R$ bands. The observations were performed with a 1.02 m optical telescope from 2007 March 07 to 2012 May 16. The $F$-test, ... More
A characterization of the unitary highest weight modules by Euclidean Jordan algebrasMar 29 2012Nov 28 2012Let $\mathfrak{co}(J)$ be the conformal algebra of a simple Euclidean Jordan algebra $J$. We show that a (non-trivial) unitary highest weight $\mathfrak{co}(J)$-module has the smallest positive Gelfand-Kirillov dimension if and only if a certain quadratic ... More
A Unified Algebraic Approach to Classical Yang-Baxter EquationJul 28 2007In this paper, the different operator forms of classical Yang-Baxter equation are given in the tensor expression through a unified algebraic method. It is closely related to left-symmetric algebras which play an important role in many fields in mathematics ... More
Quantum Teichmüller spaces and Kashaev's 6j-symbolsJun 14 2007The Kashaev invariants of 3-manifolds are based on $6j$-symbols from the representation theory of the Weyl algebra, a Hopf algebra corresponding to the Borel subalgebra of $U_q(sl(2,\C))$. In this paper, we show that Kashaev's $6j$-symbols are intertwining ... More
Extremes of $L^p$-norm of Vector-valued Gaussian processes with TrendJun 26 2017Jun 01 2018Let $\boldsymbol{X}(t)=(X_1(t),\ldots,X_d(t))$ be a Gaussian vector process and $g(t)$ be a continuous function. The asymptotics of distribution of $\left\|\boldsymbol{X}(t)\right\|_p$, the $L^p$ norm for Gaussian finite-dimensional vector, have been ... More
${\mathcal O}$-operators of Loday algebras and analogues of the classical Yang-Baxter equationSep 21 2009We introduce notions of ${\mathcal O}$-operators of the Loday algebras including the dendriform algebras and quadri-algebras as a natural generalization of Rota-Baxter operators. The invertible $\mathcal O$-operators give a sufficient and necessary condition ... More
Left-symmetric Bialgebras and An Analogue of the Classical Yang-Baxter EquationAug 11 2007We introduce a notion of left-symmetric bialgebra which is an analogue of the notion of Lie bialgebra. We prove that a left-symmetric bialgebra is equivalent to a symplectic Lie algebra with a decomposition into a direct sum of the underlying vector spaces ... More
Topological Excitations in Doped Spin LaddersJun 24 1999Aug 07 1999We study low-energy magnetic excitations of doped spin-ladders, based on an effective Hamiltonian describing interactions of mobile spin and background spins. The helicity modulus against fluctuations in the ladder plane as well as out-of-the-plane are ... More
Presence of Exotic Electronic Surface States in LaBi and LaSbJul 14 2016Nov 01 2016Extremely high magnetoresistance (XMR) in the lanthanum monopnictides La$X$ ($X$ = Sb, Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative ... More
The infrared and optical variability of OJ 287Sep 01 1998In this paper, the long-term historical optical (UBVRI) and near-infrared (JHK) data are presented with some new observations in the optical (February 1994-January 1995) and near-infrared (November 1995) bands included for BL Lac object OJ287. The new ... More
Long-term Variation of AGNsSep 02 1998In this paper, we will discuss the long-term variations in the optical and the infrared bands of some AGNs. It is interesting to note that the reported periods of AGNs are of the similar values (about 10 years, see Fan et al. 1998a, ApJ, 507 in press, ... More
Triple sign reversal of Hall effect in HgBa_{2}CaCu_{2}O_{6} thin films after heavy-ion irradiationsMar 31 1999Triple sign reversal in the mixed-state Hall effect has been observed for the first time in ion-irradiated HgBa_{2}CaCu_{2}O_{6} thin films. The negative dip at the third sign reversal is more pronounced for higher fields, which is opposite to the case ... More
The correlation between quarter point angle and nuclear radiusJan 18 2016Aug 15 2016The main objective of the present work is to correlate quarter-point angle and nuclear radius or nuclear matter distribution. Various phenomenological formulae with parameters for strong absorption radius Rs are obtained and compared by fitting the experimental ... More
Hydrogen lines in LAMOST low resolution spectra of RR Lyrae starsJun 17 2013Jun 20 2013The LAMOST spectroscopic survey for Galactic structure and evolution has been in operation since October 2012, following a one-year pilot survey. The pilot survey produced a data release containing over 600,000 stellar spectra. By cross-checking with ... More
Fabrication and Characterization of Large Area Metallic Nano-Split-Ring Arrays by Nanoimprint LithographyFeb 10 2008This paper presents a novel method to parallel fabricate large area (wafer scale) metallic nano-split-ring arrays with nanoimprint lithography (NIL). To our knowledge it is the first method that can pattern large area and high dense metallic split-ring ... More
An Empirical Template Library for FGK and Late--type A Stars Using LAMOST Observed SpectraNov 01 2018We present an empirical stellar spectra library created using spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR5. This library represents a uniform data set ranging from 3750 through 8500K in effective temperature ... More
Probing Growth-Induced Anisotropic Thermal Transport in CVD Diamond Membranes by Multi-frequency and Multi-spot-size Time-Domain ThermoreflectanceAug 01 2017The maximum output power of GaN-based high-electron mobility transistors is limited by high channel temperature induced by localized self-heating which degrades device performance and reliability. With generated heat fluxes within these devices reaching ... More
The Wigner-Yanase information can increase under phase sensitive incoherent operationsMay 01 2015We found that the Wigner-Yanase skew information, which has been recently proposed as a measure of coherence in [Phys. Rev. Lett. \textbf{113}, 170401(2014)], can increase under a class of operations which may be interpreted as incoherent following the ... More
Convergence Rates of Spectral Distribution of Large Dimensional Quaternion Sample Covariance MatrixDec 25 2013In this paper, we study the convergence rates of empirical spectral distribution of large dimensional quaternion sample covariance matrix. Assume that the entries of $\mathbf X_n$ ($p\times n$) are independent quaternion random variables with mean zero, ... More
Power-Law Energy Splitting Generated By Tunneling Between Non-smooth ToriOct 21 2001Dec 20 2001We discuss the energy level splitting $\Delta\epsilon$ due to quantum tunneling between congruent tori in phase space. In analytic cases, it is well known that $\Delta\epsilon$ decays faster than power of $\hbar$ in the semi-classical limit. This is not ... More
Convergence rate of eigenvector empirical spectral distribution of large Wigner matricesNov 21 2016In this paper, we adopt the eigenvector empirical spectral distribution (VESD) to investigate the limiting behavior of eigenvectors of a large dimensional Wigner matrix W_n. In particular, we derive the optimal bound for the rate of convergence of the ... More
Deep Enhanced Representation for Implicit Discourse Relation RecognitionJul 13 2018Implicit discourse relation recognition is a challenging task as the relation prediction without explicit connectives in discourse parsing needs understanding of text spans and cannot be easily derived from surface features from the input sentence pairs. ... More
Statistical Inferences Using Large Estimated Covariances for Panel Data and Factor ModelsJul 10 2013Nov 12 2013While most of the convergence results in the literature on high dimensional covariance matrix are concerned about the accuracy of estimating the covariance matrix (and precision matrix), relatively less is known about the effect of estimating large covariances ... More
Efficient Estimation of Approximate Factor Models via Regularized Maximum LikelihoodSep 26 2012Sep 28 2012We study the estimation of a high dimensional approximate factor model in the presence of both cross sectional dependence and heteroskedasticity. The classical method of principal components analysis (PCA) does not efficiently estimate the factor loadings ... More
Gelfand-Kirillov Dimensions of Highest Weight Harish-Chandra Modules for $SU(p,q)$Jul 09 2017May 01 2018Let $ (G,K) $ be an irreducible Hermitian symmetric pair of non-compact type with $G=SU(p,q)$, and let $ \lambda $ be an integral weight such that the simple highest weight module $ L(\lambda) $ is a Harish-Chandra $ (\mathfrak{g},K) $-module. We give ... More
On the Turán density of $\{1, 3\}$-HypergraphsFeb 16 2018In this paper, we consider the Tur\'an problems on $\{1,3\}$-hypergraphs. We prove that a $\{1, 3\}$-hypergraph is degenerate if and only if it's $H^{\{1, 3\}}_5$-colorable, where $H^{\{1, 3\}}_5$ is a hypergraph with vertex set $V=[5]$ and edge set $E=\{\{2\}, ... More
Spectral Radius of $\{0, 1\}$-Tensor with Prescribed Number of OnesJan 09 2018For any $r$-order $\{0, 1\}$-tensor $A$ with $e$ ones, we prove that the spectral radius of $A$ is at most $e^{\frac{r-1}{r}}$ with the equality holds if and only if $e={k^r}$ for some integer $k$ and all ones forms a principal sub-tensor ${\bf 1}_{k\times ... More
Complexities Approach to Two Problems In Number TheoryOct 13 2016Oct 21 2016By Kolmogorov Complexity,two number-theoretic problems are solved in different way than before,one problem is Maxim Kontsevich and Don Bernard Zagier's Problem 3 \emph{Exhibit at least one number which does not belong to} $ \mathcal{P}$ (period number) ... More
Composite Octet Searches with Jet SubstructureJul 18 2011Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new ... More
A Light Dilaton in Walking Gauge TheoriesJun 22 2010Dec 24 2010We analyze the existence of a dilaton in gauge theories with approximate infrared conformal symmetry. To the extent that these theories are governed in the infrared by an approximate fixed point (walking), the explicit breaking of the conformal symmetry ... More
Topological PionsMar 15 2010Dec 24 2010We study the collider signatures of new pions, composite particles which emerge from a TeV-scale, confining gauge theory with vector-like matter. Similar to the neutral pion in QCD, these new pions mainly decay into a pair of standard model (SM) gauge ... More
The Amplituhedron from Momentum Twistor DiagramsAug 11 2014We propose a new diagrammatic formulation of the all-loop scattering amplitudes/Wilson loops in planar N=4 SYM, dubbed the "momentum-twistor diagrams". These are on-shell-diagrams obtained by gluing trivalent black and white vertices defined in momentum ... More
Coloron-assisted Leptoquarks at the LHCJul 16 2014Recent searches for a first-generation leptoquark by the CMS collaboration have shown around 2.5 sigma deviations from Standard Model predictions in both the eejj and e nu jj channels. Furthermore, the eejj invariant mass distribution has another 2.8 ... More
On the chordality of polynomial sets in triangular decomposition in top-down styleFeb 06 2018In this paper the chordal graph structures of polynomial sets appearing in triangular decomposition in top-down style are studied when the input polynomial set to decompose has a chordal associated graph. In particular, we prove that the associated graph ... More
Signature splitting inversion and backbending in 80RbOct 22 2012High spin states of 80Rb are studied via the fusion-evaporation reactions 65Cu+19F, 66Zn+18O and 68Zn+16O with the beam energies of 75 MeV, 76 MeV and 80 MeV, respectively. Twenty-three new states with twenty-eight new \gamma transitions were added to ... More
Seiberg-Witten-Floer Theory for Homology 3-SpheresFeb 02 1996Jul 29 1996We give the definition of the Seiberg-Witten-Floer homology group for a homology 3-sphere. Its Euler characteristic number is a Casson-type invariant. For a four-manifold with boundary a homology sphere, a relative Seiberg-Witten invariant is defined ... More
Symplectic Approach of Wess-Zumino-Witten Model and Gauge Field TheoriesApr 04 1995A systematic description of the Wess-Zumino-Witten model is presented. The symplectic method plays the major role in this paper and also gives the relationship between the WZW model and the Chern-Simons model. The quantum theory is obtained to give the ... More
Parisian Ruin of the Brownian Motion Risk Model with Constant Force of InterestJun 23 2016Sep 13 2016Let $B(t), t\in \mathbb{R}$ be a standard Brownian motion. Define a risk process \label{Rudef} R_u^{\delta}(t)=e^{\delta t}\left(u+c\int^{t}_{0}e^{-\delta s}d s-\sigma\int_{0}^{t}e^{-\delta s}d B(s)\right), t\geq0, where $u\geq 0$ is the initial reserve, ... More
Dark Matter Jets at the LHCSep 27 2011We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the ... More
Top-antitop and Top-top Resonances in the Dilepton Channel at the CERN LHCSep 26 2008Apr 12 2009We perform a model-independent study for top-antitop and top-top resonances in the dilepton channel at the Large Hadtron Collider. In this channel, we can solve the kinematic system to obtain the momenta of all particles including the two neutrinos, and ... More
Microlensing of X-ray Pulsars: a Method to Detect Primordial Black Hole Dark MatterNov 28 2018Jun 17 2019Primordial black holes (PBHs) with a mass from $10^{-16}$ to $10^{-11}\,M_\odot$ may comprise 100% of dark matter. Due to a combination of wave and finite source size effects, the traditional microlensing of stars does not probe this mass range. In this ... More
Analysis of Sequential Quadratic Programming through the Lens of Riemannian OptimizationMay 22 2018Jan 31 2019We prove that a "first-order" Sequential Quadratic Programming (SQP) algorithm for equality constrained optimization has local linear convergence with rate $(1-1/\kappa_R)^k$, where $\kappa_R$ is the condition number of the Riemannian Hessian, and global ... More
On the minimal energy of tetracyclic graphsAug 06 2014The energy of a graph is defined as the sum of the absolute values of the eigenvalues of its adjacency matrix. In this paper, we characterize the tetracyclic graph of order $n$ with minimal energy. By this, the validity of a conjecture for the case $e=n+3$ ... More
Fermion Portal Dark MatterAug 02 2013Jun 23 2014We study a class of simplified dark matter models in which one dark matter particle couples with a mediator and a Standard Model fermion. In such models, collider and direct detection searches probe complimentary regions of parameter space. For Majorana ... More
Detecting Axion Stars with Radio TelescopesSep 29 2017When axion stars fly through an astrophysical magnetic background, the axion-to-photon conversion may generate a large electromagnetic radiation power. After including the interference effects of the spacially-extended axion-star source and the macroscopic ... More
Large N (=3) Neutrinos and Random Matrix TheoryOct 08 2012Nov 06 2012The large N limit has been successfully applied to QCD, leading to qualitatively correct results even for N=3. In this work, we propose to treat the number N=3 of Standard Model generations as a large number. Specifically, we apply this idea to the neutrino ... More
Geometric cycles, index theory and twisted K-homologyOct 09 2007Jul 09 2008We study twisted $Spin^c$-manifolds over a paracompact Hausdorff space $X$ with a twisting $\alpha: X \to K(\ZZ, 3)$. We introduce the topological index and the analytical index on the bordism group of $\alpha$-twisted $Spin^c$-manifolds over $(X, \alpha)$, ... More
Classification of global dynamics of competition models with nonlocal dispersals I: Symmetric kernelsApr 10 2017In this paper, we gives a complete classification of the global dynamics of two- species Lotka-Volterra competition models with nonlocal dispersals: where K, P represent nonlocal operators, under the assumptions that the nonlo- cal operators are symmetric, ... More