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Spectral Efficiency and Energy Efficiency of OFDM Systems: Impact of Power Amplifiers and CountermeasuresMay 17 2013In wireless communication systems, the nonlinear effect and inefficiency of power amplifier (PA) have posed practical challenges for system designs to achieve high spectral efficiency (SE) and energy efficiency (EE). In this paper, we analyze the impact ... More

Incentive Mechanisms for Motivating Mobile Data Offloading in Heterogeneous Networks: A Salary-Plus-Bonus ApproachFeb 08 2018In this paper, a salary-plus-bonus incentive mechanism is proposed to motivate WiFi Access Points (APs) to provide data offloading service for mobile network operators (MNOs). Under the proposed salary-plus-bonus scheme, WiFi APs are rewarded not only ... More

Full-Duplex Wireless-Powered Communication Network with Energy CausalityApr 02 2014In this paper, we consider a wireless communication network with a full-duplex hybrid access point (HAP) and a set of wireless users with energy harvesting capabilities. The HAP implements the full-duplex through two antennas: one for broadcasting wireless ... More

Data Offloading in Load Coupled Networks: A Utility Maximization FrameworkDec 25 2013We provide a general framework for the problem of data offloading in a heterogeneous wireless network, where some demand of cellular users is served by a complementary network. The complementary network is either a small-cell network that shares the same ... More

On Tractability Aspects of Optimal Resource Allocation in OFDMA SystemsDec 11 2011Joint channel and rate allocation with power minimization in orthogonal frequency-division multiple access (OFDMA) has attracted extensive attention. Most of the research has dealt with the development of sub-optimal but low-complexity algorithms. In ... More

Power and Channel Allocation for Non-orthogonal Multiple Access in 5G Systems: Tractability and ComputationMar 24 2016Network capacity calls for significant increase for 5G cellular systems. A promising multi-user access scheme, non-orthogonal multiple access (NOMA) with successive interference cancellation (SIC), is currently under consideration. In NOMA, spectrum efficiency ... More

Cost minimization for fading channels with energy harvesting and conventional energyApr 04 2014In this paper, we investigate resource allocation strategies for a point-to-point wireless communications system with hybrid energy sources consisting of an energy harvester and a conventional energy source. In particular, as an incentive to promote the ... More

Gaussian Two-way Relay Channel with Private Information for the RelaySep 19 2011We introduce a generalized two-way relay channel where two sources exchange information (not necessarily of the same rate) with help from a relay, and each source additionally sends private information to the relay. We consider the Gaussian setting where ... More

On Power and Load Coupling in Cellular Networks for Energy OptimizationFeb 24 2014Aug 26 2014We consider the problem of minimization of sum transmission energy in cellular networks where coupling occurs between cells due to mutual interference. The coupling relation is characterized by the signal-to-interference-and-noise-ratio (SINR) coupling ... More

Fountain Codes with Varying Probability DistributionsJan 12 2010Apr 07 2010Fountain codes are rateless erasure-correcting codes, i.e., an essentially infinite stream of encoded packets can be generated from a finite set of data packets. Several fountain codes have been proposed recently to minimize overhead, many of which involve ... More

Optimal Cell Clustering and Activation for Energy Saving in Load-Coupled Wireless NetworksFeb 15 2015Mar 25 2015Optimizing activation and deactivation of base station transmissions provides an instrument for improving energy efficiency in cellular networks. In this paper, we study optimal cell clustering and scheduling of activation duration for each cluster, with ... More

Carrier Frequency Offset Estimation for Two-Way Relaying: Optimal Preamble and Estimator DesignAug 16 2012We consider the problem of carrier frequency offset (CFO) estimation for a two-way relaying system based on the amplify-and-forward (AF) protocol. Our contributions are in designing an optimal preamble, and the corresponding estimator, to closely achieve ... More

Massive MIMO versus Small-Cell Systems: Spectral and Energy Efficiency ComparisonSep 14 2015In this paper, we study the downlink performance of two important 5G network architectures, i.e. massive multiple-input multiple-output (M-MIMO) and small-cell densification. We propose a comparative modeling for the two systems, where the user and antenna/base ... More

Stochastic Geometry-Based Performance Bounds for Non-Fading and Rayleigh Fading Ad Hoc NetworksSep 14 2015In this paper, we study the performance of non-fading and Rayleigh fading ad hoc networks. We first characterize the distribution of the signal-to-interference-plus-noise ratio (SINR) through the Laplace transform of the inverted SINR for non-fading channels. ... More

Principal Component Analysis (PCA)-based Massive-MIMO Channel FeedbackDec 16 2015Channel-state-information (CSI) feedback methods are considered, especially for massive or very large-scale multiple-input multiple-output (MIMO) systems. To extract essential information from the CSI without redundancy that arises from the highly correlated ... More

Improper Signaling for Symbol Error Rate Minimization in K-User Interference ChannelMay 29 2014The rate maximization for the $K$-user interference channels (ICs) has been investigated extensively in the literature. However, the dual problem of minimizing the error probability with given signal modulations and/or data rates of the users is less ... More

Energy Cooperation in Cellular Networks with Renewable Powered Base StationsJan 21 2013May 27 2013In this paper, we propose a model for energy cooperation between cellular base stations (BSs) with individual hybrid power supplies (including both the conventional grid and renewable energy sources), limited energy storages, and connected by resistive ... More

Electromagnetically induced transparency and optical memories in an optomechanical system with $N$ membranesMar 06 2014We study the propagation of a weak probe field through an optomechanical system in which $N$ nearly degenerate mechanical membranes are inside a Febry-Perot cavity, and couple dispersively to an intracavity field. We derive a general analytical expression ... More

Opportunistic Multicast Scheduling for Unicast Transmission in MIMO-OFDM SystemNov 11 2014We propose a multicast scheduling scheme to exploit content reuse when there is asynchronicity in user requests. A unicast transmission setup is used for content delivery, while multicast transmission is employed opportunistically to reduce wireless resource ... More

Comparative Study of SVD and QRS in Closed-Loop Beamforming SystemsJun 23 2008We compare two closed-loop beamforming algorithms, one based on singular value decomposition (SVD) and the other based on equal diagonal QR decomposition (QRS). SVD has the advantage of parallelizing the MIMO channel, but each of the sub-channels has ... More

Comparative Study of Open-loop Transmit Diversity Schemes for Four Transmit Antennas in Coded OFDM SystemsJun 23 2008We compare four open-loop transmit diversity schemes in a coded Orthogonal Frequency Division Multiplexing (OFDM) system with four transmit antennas, namely cyclic delay diversity (CDD), Space-Time Block Code (STBC, Alamouti code is used) with CDD, Quasi-Orthogonal ... More

Energy-Efficient, Large-scale Distributed-Antenna System (L-DAS) for Multiple UsersDec 06 2013Jan 20 2014Large-scale distributed-antenna system (L-DAS) with very large number of distributed antennas, possibly up to a few hundred antennas, is considered. A few major issues of the L-DAS, such as high latency, energy consumption, computational complexity, and ... More

Robust force sensing for a free particle in a dissipative optomechanical system with a parametric amplifierOct 10 2016We theoretically investigate optical detection of a weak classical force acting on a free particle in a dissipative coupling optomechanical system with a degenerate parametric amplifier (PA). We show that the PA allows one to achieve the force sensitivity ... More

Modulated Unit-Norm Tight Frames for Compressed SensingNov 27 2014In this paper, we propose a compressed sensing (CS) framework that consists of three parts: a unit-norm tight frame (UTF), a random diagonal matrix and a column-wise orthonormal matrix. We prove that this structure satisfies the restricted isometry property ... More

Energy-Efficient Relaying over Multiple Slots with Causal CSIMay 22 2012Nov 29 2012In many communication scenarios, such as in cellular systems, the energy cost is substantial and should be conserved, yet there is a growing need to support many real-time applications that require timely data delivery. To model such a scenario, in this ... More

Iterative Channel Estimation Using LSE and Sparse Message Passing for MmWave MIMO SystemsNov 17 2016We propose an iterative channel estimation algorithm based on the Least Square Estimation (LSE) and Sparse Message Passing (SMP) algorithm for the Millimeter Wave (mmWave) MIMO systems. The channel coefficients of the mmWave MIMO are approximately modeled ... 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

Deterministic Sequences for Compressive MIMO Channel EstimationNov 02 2013This paper considers the problem of pilot design for compressive multiple-input multiple-output (MIMO) channel estimation. In particular, we are interested in estimating the channels for multiple transmitters simultaneously when the pilot sequences are ... More

Mobile Data Offloading through A Third-Party WiFi Access Point: An Operator's PerspectiveAug 22 2014WiFi offloading is regarded as one of the most promising techniques to deal with the explosive data increase in cellular networks due to its high data transmission rate and low requirement on devices. In this paper, we investigate the mobile data offloading ... More

Ergodic Sum-Rate Maximization for Fading Cognitive Multiple Access Channels without Successive Interference CancellationMar 03 2014In this paper, the ergodic sum-rate of a fading cognitive multiple access channel (C-MAC) is studied, where a secondary network (SN) with multiple secondary users (SUs) transmitting to a secondary base station (SBS) shares the spectrum band with a primary ... More

A LSE and Sparse Message Passing-Based Channel Estimation for mmWave MIMO SystemsSep 11 2016In this paper, we propose a novel channel estimation algorithm based on the Least Square Estimation (LSE) and Sparse Message Passing algorithm (SMP), which is of special interest for Millimeter Wave (mmWave) systems, since this algorithm can leverage ... More

Enhancement of Cavity Cooling of a Micromechanical Mirror Using Parametric InteractionsOct 15 2008Feb 04 2009It is shown that an optical parametric amplifier inside a cavity can considerably improve the cooling of the micromechanical mirror by radiation pressure. The micromechanical mirror can be cooled from room temperature 300 K to sub-Kelvin temperatures, ... More

Nanomechanical Inverse Electromagnetically Induced Transparency and Confinement of Light in Normal modesApr 27 2013Mar 27 2014We demonstrate the existence of the phenomenon of the inverse electromagnetically induced transparency (IEIT) in an opto mechanical system consisting of a nanomechanical mirror placed in an optical cavity. We show that two weak counter-propagating identical ... More

The Electromagnetically Induced Transparency in Mechanical Effects of LightNov 21 2009Apr 24 2010We consider the dynamical behavior of a nanomechanical mirror in a high-quality cavity under the action of a coupling laser and a probe laser. We demonstrate the existence of the analog of electromagnetically induced transparency (EIT) in the output field ... More

Normal mode splitting in a coupled system of nanomechanical oscillator and parametric amplifier cavityApr 21 2009Jun 24 2009We study how an optical parametric amplifier inside the cavity can affect the normal mode splitting behavior of the coupled movable mirror and the cavity field. We work in the resolved sideband regime. The spectra exhibit a double-peak structure as the ... More

Optomechanical Systems as Single Photon RoutersSep 20 2011Feb 03 2012We demonstrate theoretically the possibility of using nano mechanical systems as single photon routers. We show how EIT in cavity optomechanical systems can be used to produce a switch for a probe field in a single photon Fock state using very low pumping ... More

Strong Mechanical Squeezing and its DetectionFeb 06 2016Mar 17 2016We report an efficient mechanism to generate a squeezed state of a mechanical mirror in an optomechanical system. We use especially tuned parametric amplifier (PA) inside the cavity and the parametric photon phonon processes to transfer quantum squeezing ... More

Weak value amplification of atomic cat statesJan 10 2015Sep 09 2015We show the utility of the weak value amplification to observe the quantum interference between two close lying atomic coherent states in a post-selected atomic cat state, produced in a system of $N$ identical two-level atoms weakly interacting with a ... More

Coherent perfect absorption of path entangled single photonsFeb 28 2014Aug 22 2014We examine the question of coherent perfect absorption (CPA) of single photons, and more generally, of the quantum fields by a {\it macroscopic} medium. We show the CPA of path entangled single photons in a Fabry-Perot interferometer containing an absorptive ... More

Can reactive coupling beat motional quantum limit of nano waveguides coupled to microdisk resonatorJul 09 2010Oct 05 2010Dissipation is generally thought to affect the quantum nature of the system in an adverse manner, however we show that dissipatively coupled nano systems can be prepared in states which beat the standard quantum limit of the mechanical motion. We show ... More

Squeezing of a nanomechanical oscillatorMay 26 2009We show that squeezing of a nanomechanical mirror can be generated by injecting broad band squeezed vacuum light and laser light into the cavity. We work in the resolved sideband regime. We find that in order to obtain the maximum momentum squeezing of ... More

Reactive-Coupling-Induced Normal Mode Splittings in Microdisk Resonators Coupled to WaveguidesFeb 15 2010May 09 2010We study the optomechanical design introduced by M. Li et al. [Phys. Rev. Lett. {\bf 103}, 223901 (2009)], which is very effective for investigation of the effects of reactive coupling. We show the normal mode splitting which is due solely to reactive ... More

SPLZ: An Efficient Algorithm for Single Source Shortest Path Problem Using Compression MethodAug 11 2014Jan 11 2015Efficient solution of the single source shortest path (SSSP) problem on road networks is an important requirement for numerous real-world applications. This paper introduces an algorithm for the SSSP problem using compression method. Owning to precomputing ... More

Projective embedding of log Riemann surfaces and K-stabilityMay 03 2016Aug 16 2016Given a smooth polarized Riemann surface (X, L) endowed with a hyperbolic metric $\omega$ with cusp singularities along a divisor D, we show the L^2 projective embedding of (X, D) defined by L^k is asymptotically almost balanced in a weighted sense. The ... More

Electromagnetically Induced Transparency with Quantized Fields in Optocavity MechanicsFeb 01 2011Feb 10 2011We report electromagnetically induced transparency using quantized fields in optomechanical systems. The weak probe field is a narrow band squeezed field. We present a homodyne detection of EIT in the output quantum field. We find that the EIT dip exists ... More

Electromagnetically Induced Transparency from Two Phonon Processes in Quadratically Coupled MembranesOct 05 2010We describe how electromagnetically induced transparency can arise in quadratically coupled optomechanical systems. Due to quadratic coupling the underlying optical process involves a two phonon process in optomechanical system and this two phonon process ... More

Normal Mode Splitting and Antibunching in Stokes and Anti-Stokes Processes in Cavity Optomechanics: Radiation Pressure Induced Four-Wave Mixing Cavity OptomechanicsSep 10 2009Mar 30 2010We study Stokes and anti-Stokes processes in cavity optomechanics in the regime of strong coupling. The Stokes and anti-Stokes signals exhibit prominently the normal-mode splitting. We report gain for the Stokes signal. We also report lifetime splitting ... More

Entangling nanomechanical oscillators in a ring cavity by feeding squeezed lightAug 11 2009Oct 28 2009A scheme is presented for entangling two separated nanomechanical oscillators by injecting broad band squeezed vacuum light and laser light into the ring cavity. We work in the resolved sideband regime. We find that in order to obtain the maximum entanglement ... More

Finite dimensional representations of the rational Cherednik algebra for $G_4$Oct 29 2009In this paper, we study representations of the rational Cherednik algebra associated to the complex reflection group $G_4$. In particular, we classify the irreducible finite dimensional representations and compute their characters.

Investigation of Volume Phase Transition from the Different Properties of ParticlesNov 18 2005In this work, three different particle sizes: the static radius $R_{s}$, hydrodynamic radius $R_{h}$ and apparent hydrodynamic radius $ R_{h,app}$ obtained using the light scattering technique, are investigated for dilute poly-disperse homogenous spherical ... More

Zero entropy invariant measures for some skew product diffeomorphismsDec 15 2008In this paper we study some skew product diffeomorphisms with nonuniformly hyperbolic structure along fibers. We show that there is an invariant measure with zero entropy which has atomic conditional measures along fibers.

A probabilistic approach for enumeration of certain Young tableauxFeb 04 2013In this paper we establish an order statistics model of Young tableaux. Multiple integration over nested simplexes is applied to the enumeration of Young tableaux. A brief proof of Frobenius-Young's and Aitken's formulas is given. Partially standard Young ... More

Entropy and Ergodic Measures for Toral AutomorphismsMar 06 2011We show that for every linear toral automorphism, especially the non-hyperbolic ones, the entropies of ergodic measures form a dense set on the interval from zero to the topological entropy.

Necessity of numerical smoothnessJul 12 2012Numerical solutions of differential equations are usually not smooth functions. However, they should resemble the smoothness of the corresponding real solutions in one way or another. In two of our recent papers, a kind of spacial smoothness indicators ... More

OPESCI-FD: Automatic Code Generation Package for Finite Difference ModelsMay 20 2016In this project, we introduce OPESCI-FD, a Python package built on symbolic mathematics to automatically generate Finite Difference models from a high-level description of the model equations. We investigate applying this framework to generate the propagator ... More

Tilt-stability, vanishing theorems for stable sheaves and applicationsSep 12 2016We study the tilt-stability of stable sheaves on projective varieties with respect to certain tilt-stability conditions depends on two parameters. For a stable sheaf, we give some effective bounds of these parameters such that the stable sheaf is tilt-stable. ... More

Probe Anomalous $tqγ$ couplings through Single Top Photoproduction at the LHCFeb 08 2014Jul 17 2014In this work we study the constraints on the anomalous $tq\gamma$ ($q=u$, $c$) couplings by photon-produced leading single top production and single top jet associated production through the main reaction $pp\rightarrow p\gamma p\rightarrow pt\rightarrow ... More

The nonvanishing hypothesis at infinity for Rankin-Selberg convolutionsJul 20 2013Dec 02 2015We prove the nonvanishing hypothesis at infinity for Rankin-Selberg convolutions for $\GL(n)\times \GL(n-1)$.

Stability Criterion for Convolution-Dominated Infinite MatricesJul 22 2009Let $\ell^p$ be the space of all $p$-summable sequences on $\mathbb{Z}$. An infinite matrix is said to have $\ell^p$-stability if it is bounded and has bounded inverse on $\ell^p$. In this paper, a practical criterion is established for the $\ell^p$-stability ... More

Logarithmic heat projective operatorsSep 21 2000Let $f:\Cal C\to S$ be a flat family of curves over a smooth curve $S$ such that $f$ is smooth over $S_0=S\ssm\{s_0\}$ and $f^{-1}(s_0)=\Cal C_0$ is irreducible with one node. We have an associated family $\Cal M_{S_0}\to S_0$ of moduli spaces of semistable ... More

Degeneration of moduli spaces and generalized theta functionsJul 29 1999We prove a factorization theorem of generalized functions for moduli spaces of semistable parabolic bundles of any rank.

Topological Symmetries of R^3, IIMar 10 2016If a fintie group G acts topologically and faithfully on R^3, then G is a subgroup of O(3)

Convergence of Coalescing Nonsimple Random Walks to the Brownian WebJan 10 2005The Brownian Web (BW) is a family of coalescing Brownian motions starting from every point in space and time $\R\times\R$. It was first introduced by Arratia, and later analyzed in detail by T\'{o}th and Werner. More recently, Fontes, Isopi, Newman and ... More

Model actions for almost reduced groups on UHF algebrasSep 24 2014For any countable discrete group $G$ with a reduced abelian subgroup of finite index, we construct an action $\alpha$ of $G$ on the universal UHF algebra $\Qq$ using an infinite tensor product of permutation representations of $G$ and show that these ... More

The general $J$-flowsJul 31 2015We study the general $J$-flows. We use Moser iteration to obtain the uniform estimate.

Physical Angular Momentum Separation for QEDAug 18 2016We study the non-uniqueness problem of the gauge-invariant angular momentum separation for the case of QED, which stems from the recent controversy concerning the proper definitions of the orbital angular momentum and spin operator of the individual parts ... More

Covering a cubic graph by 5 perfect matchingsJan 13 2016Feb 29 2016Berge Conjecture states that every bridgeless cubic graph has 5 perfect matchings such that each edge is contained in at least one of them. In this paper, we show that Berge Conjecture holds for two classes of cubic graphs, cubic graphs with a circuit ... More

Traces of intertwiners for quantum affine sl_2 and Felder-Varchenko functionsAug 17 2015Dec 06 2015We show that the traces of $U_q(\widehat{\mathfrak{sl}}_2)$-intertwiners of Etingof-Schiffmann-Varchenko valued in the three-dimensional evaluation representation converge in a certain region of parameters and give a representation-theoretic construction ... More

Laguerre and Jacobi analogues of the Warren processOct 05 2016We define Laguerre and Jacobi analogues of the Warren process. That is, we construct local dynamics on a triangular array of particles so that the projections to each level recover the Laguerre and Jacobi eigenvalue processes of K\"onig-O'Connell and ... More

Virtual homological eigenvalue and mapping torus of pseudo-Anosov mapsAug 25 2016In this note, we show that, if a pseudo-Anosov map $\phi:S\to S$ admits a finite cover which has a homological eigenvalue with modulus greater than $1$, then the monodromy of any fibered structure of any finite cover of $M_{\phi}$ has this property.

On Noether approach in the cosmological model with scalar and gauge fields: symmetries and the selection ruleApr 18 2015In this paper, based on the works of Capozziello et al., we have studied the Noether symmetry approach in the cosmological model with scalar and gauge fields proposed recently by Soda et al. The correct Noether symmetries and related Lie algebra are given ... More

Decomposition Theorem for Perverse sheaves on Artin stacks over finite fieldsSep 22 2010Mar 11 2012We generalize the decomposition theorem for perverse sheaves to Artin stacks with affine stabilizers over finite fields.

L-series of Artin stacks over finite fieldsAug 22 2010Mar 28 2011We reprove the Lefschetz trace formula for stacks (in the context of derived categories and the six operations for stacks developed by Laszlo and Olsson), and give the meromorphic continuation of L-series (in particular, zeta functions) of Artin stacks ... More

Axisymmetrically Tropical Cyclone-like Vortices with Secondary CirculationsSep 07 2013The secondary circulation of the tropical cyclone (TC) is related to its formation and intensification, thus becomes very important in the studies. The analytical solutions have both the primary and secondary circulation in a three-dimensionally nonhydrostatic ... More

Identify the diapycnical eddy diffusivities by salt fingers and turbulence with vertical microstructure measurementsJun 23 2014Diapycnical eddy diffusivities are formulated from physical relations according to a simple fact that the different formulas are identical for the same parameter. It is found that the dispassion ratio \Gamma is a crucial parameter. When it is above a ... More

Fock-Goncharov coordinates and rank $n$ swapping algebraMar 03 2015Jun 10 2016In our previous paper arXiv:math/1411.2796, we introduced the rank $n$ swapping algebra---a Poisson algebra associated to an affine variety defined by pairs of points on a circle and their determinant relations. Let the rank $n$ swapping multifraction ... More

Morphological Structures of Planetary NebulaeNov 30 2009Since various structural components of planetary nebulae manifest themselves differently, a combination of optical, infrared, submm, and radio techniques is needed to derive a complete picture of planetary nebulae. The effects of projection can also make ... More

Character tables of Sylow $p$-subgroups ${^3}D_4^{syl}(q^3)$ of the Steinberg triality groupsJun 20 2016We determine the character tables of Sylow $p$-subgroups ${^3}D_4^{syl}(q^3)$ of the Steinberg triality groups ${^3}D_4(q^3)$.

Eisenstein integrals for theta stable parabolic subalgebrasMar 25 2004Nov 28 2004Let $G$ be a connected semisimple Lie group with a finite center, with a maximal compact subgroup $K$. There are two general methods to construct representations of $G$, namely, ordinary parabolic induction and cohomological parabolic induction. We define ... More

Exponential Decay of Lebesgue NumbersFeb 02 2010Nov 20 2010We study the exponential rate of decay of Lebesgue numbers of open covers in topological dynamical systems. We show that topological entropy is bounded by this rate multiplied by dimension. Some corollaries and examples are discussed.

Mott-Hubbard Scenario for the Metal-Insulator Transition in the Two Dimensional Electron GasAug 01 2006By comparing the responses to an in-plane magnetic field near the metal-insulator transition (MIT), we find that the observed MIT in Si MOSFETs can be described by the non-perturbative Mott-Hubbard scenario. Interrelations between independent measurables ... More

A Simulation and Modeling of Access Points with Definition LanguageApr 06 2013Apr 11 2013This submission has been withdrawn by arXiv administrators because it contains fictitious content and was submitted under a pseudonym, which is against arXiv policy.

Arithmetic genus of integral space curvesMay 23 2016We give an estimation for the arithmetic genus of an integral space curve, which are not contained in a surface of degree $k-1$. Our main technique is the Bogomolov-Gieseker type inequality for $\mathbb{P}^3$ proved by Macri.

Large Extra Dimension effects through Light-by-Light Scattering at the CERN LHCJun 16 2014Jul 31 2014Observing light-by-light scattering at the Large Hadron Collider (LHC) has received quite some attention and it is believed to be a clean and sensitive channel to possible new physics. In this paper, we study the diphoton production at the LHC via the ... More

Dual pairs and contragredients of irreducible representationsMar 08 2009Dec 08 2009Let $G$ be a classical group $\GL(n)$, $\oU(n)$, $\oO(n)$ or $\Sp(2n)$, over a non-archimedean local field of characteristic zero. Let $\pi$ be an irreducible admissible smooth representation of $G$. It is well known that the contragredient of $\pi$ is ... More

Almost linear Nash groupsOct 30 2013Nov 21 2013A Nash group is said to be almost linear if it has a Nash representation with finite kernel. Structures and basic properties of these groups are studied.

Cohomologically induced distinguished representations and cohomological test vectorsNov 11 2011Jan 30 2015Let $G$ be a real reductive group, and let $\chi$ be a character of a reductive subgroup $H$ of $G$. We construct $\chi$-invariant linear functionals on certain cohomologically induced representations of $G$, and show that these linear functionals do ... More

NonLERFness of arithmetic hyperbolic manifold groupsAug 17 2016We will show that, for any noncompact arithmetic hyperbolic $m$-manifold with $m\geq 4$, and any compact arithmetic hyperbolic $m$-manifold with $m\geq 5$ which is not a $7$-dimensional arithmetic hyperbolic manifold defined by octonions, its fundamental ... More

A note on simultaneous nonvanishing of Dirichlet $L$-functions and twists of Hecke-Maass $L$-functionsSep 10 2016In this note, we prove that given a Hecke-Maass cusp form $f$ for $SL_2(\mathbb{Z})$ and a sufficiently large integer $q=q_1q_2$ with $q_j\asymp \sqrt{q}$ being prime numbers for $j=1,2$, there exists a primitive Dirichlet character $\chi$ of conductor ... More

Localized nonlinear functional equations and two sampling problems in signal processingApr 09 2013Let $1\le p\le \infty$. In this paper, we consider solving a nonlinear functional equation $$f(x)=y,$$ where $x, y$ belong to $\ell^p$ and $f$ has continuous bounded gradient in an inverse-closed subalgebra of ${\mathcal B}(\ell^2)$, the Banach algebra ... More

Libcint: An efficient general integral library for Gaussian basis functionsDec 01 2014An efficient integral library Libcint was designed to automatically implement general integrals for Gaussian-type scalar and spinor basis functions. The library can handle arbitrary integral expressions on top of $\mathbf{p}$, $\mathbf{r}$ and $\sigma$ ... More

Wiener's Lemma for Infinite Matrices IIJan 09 2010In this paper, we introduce a class of infinite matrices related to the Beurling algebra of periodic functions, and we show that it is an inverse-closed subalgebra of ${\mathcal B}(\ell^q_w)$, the algebra of all bounded linear operators on the weight ... More

Towards Shockingly Easy Structured Classification: A Search-based Probabilistic Online Learning FrameworkMar 29 2015There are two major approaches for structured classification. One is the probabilistic gradient-based methods such as conditional random fields (CRF), which has high accuracy but with drawbacks: slow training, and no support of search-based optimization ... More

Demosaicing and Superresolution for Color Filter Array via Residual Image Reconstruction and Sparse RepresentationSep 29 2012Jul 04 2013A framework of demosaicing and superresolution for color filter array (CFA) via residual image reconstruction and sparse representation is presented.Given the intermediate image produced by certain demosaicing and interpolation technique, a residual image ... More

Conformally invariant scaling limits in planar critical percolationNov 02 2009Oct 21 2011This is an introductory account of the emergence of conformal invariance in the scaling limit of planar critical percolation. We give an exposition of Smirnov's theorem (2001) on the conformal invariance of crossing probabilities in site percolation on ... More

Multiple recurrence and convergence for certain averages along shifted primesMar 15 2013Feb 03 2014We show any subset $A\subset\mathbb{N}$ with positive upper Banach density contains the pattern $\{m,m+[n\alpha],\dots,m+k[n\alpha]\}$, for some $m\in\mathbb{N}$ and $n=p-1$ for some prime $p$, where $\alpha\in\mathbb{R}\backslash\mathbb{Q}$. Making use ... More

Why are there strong radio AGNs in the center of "non-cool core" clusters?Oct 05 2009Radio AGN feedback in X-ray cool cores has been proposed as a crucial ingredient in the evolution of baryonic structures. However, it has long been known that strong radio AGNs also exist in "noncool core" clusters, which brings up the question whether ... More

Every BCG with a strong radio AGN has an X-ray cool core: is the cool core - noncool core dichotomy too simple?Apr 13 2009Sep 20 2009Radio AGN feedback in X-ray cool cores has been proposed as a crucial ingredient in the evolution of baryonic structures. However, it has long been known that strong radio AGN also exist in "noncool core" clusters, which brings up the question whether ... More

Confining the light wave by using non-Euclidean transformation opticsFeb 03 2013Sep 24 2013A new way to understand why some inhomogeneous dielectric medium can be used for confining the light wave has been given by using non-Euclidean transformation optics. We show that special inhomogeneous dielectric medium, which corresponds to a dip in ... More

Different Particle Sizes Obtained from Static and Dynamic Laser Light ScatteringMay 31 2004Dec 08 2004Detailed investigation of static and dynamic laser light scattering has been attempted in this work both theoretically and experimentally based on dilute water dispersions of two different homogenous spherical particles, polystyrene latexes and poly($N$-isopropylacrylamide) ... More