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Quantum phase estimation of multiple eigenvalues for small-scale (noisy) experimentsSep 25 2018Dec 17 2018Quantum phase estimation is the workhorse behind any quantum algorithm and a promising method for determining ground state energies of strongly correlated quantum systems. Low-cost quantum phase estimation techniques make use of circuits which only use ... More

Chiral symmetry and bulk--boundary correspondence in periodically driven one-dimensional systemsMay 07 2014Aug 28 2014Over the past few years, topological insulators have taken center stage in solid state physics. The desire to tune the topological invariants of the bulk and thus control the number of edge states has steered theorists and experimentalists towards periodically ... More

A fast, low-leakage, high-fidelity two-qubit gate for a programmable superconducting quantum computerMar 06 2019A common approach to realize conditional-phase (CZ) gates in transmon qubits relies on flux control of the qubit frequency to make computational states interact with non-computational ones using a fast-adiabatic trajectory to minimize leakage. We develop ... More

Andreev-Bragg reflection from an Amperian superconductorSep 09 2014Mar 14 2015We show how an electrical measurement can detect the pairing of electrons on the same side of the Fermi surface (Amperian pairing), recently proposed by Patrick Lee for the pseudogap phase of high-$T_c$ cuprate superconductors. Bragg scattering from the ... More

Scattering theory of topological phases in discrete-time quantum walksJan 12 2014Jan 24 2014One-dimensional discrete-time quantum walks show a rich spectrum of topological phases that have so far been exclusively analysed in momentum space. In this work we introduce an alternative approach to topology which is based on the scattering matrix ... More

Density-matrix simulation of small surface codes under current and projected experimental noiseMar 12 2017Jan 08 2018We present a full density-matrix simulation of the quantum memory and computing performance of the distance-3 logical qubit Surface-17, following a recently proposed quantum circuit and using experimental error parameters for transmon qubits in a planar ... More

Spin-orbit interaction in InSb nanowiresDec 02 2014May 18 2015We use magnetoconductance measurements in dual-gated InSb nanowire devices together with a theoretical analysis of weak antilocalization to accurately extract spin-orbit strength. In particular, we show that magnetoconductance in our three-dimensional ... More

Attractor-repeller pair of topological zero-modes in a nonlinear quantum walkNov 20 2015Feb 12 2016The quantum-mechanical counterpart of a classical random walk offers a rich dynamics that has recently been shown to include topologically protected bound states (zero-modes) at boundaries or domain walls. Here we show that a topological zero-mode may ... More

Time-domain characterization and correction of on-chip distortion of control pulses in a quantum processorJul 10 2019We introduce Cryoscope, a method for sampling on-chip baseband pulses used to dynamically control qubit frequency in a quantum processor. We specifically use Cryoscope to measure the step response of the dedicated flux control lines of two-junction transmon ... More

Quench dynamics of fermion-parity switches in a Josephson junctionMar 13 2015Sep 18 2015A Josephson junction may be driven through a transition where the superconducting condensate favors an odd over an even number of electrons. At this switch in the ground-state fermion parity, an Andreev bound state crosses through the Fermi level, producing ... More

Protecting quantum entanglement from qubit errors and leakage via repetitive parity measurementsMay 29 2019Protecting quantum information from errors is essential for large-scale quantum computation. Quantum error correction (QEC) encodes information in entangled states of many qubits, and performs parity measurements to identify errors without destroying ... More

Machine-learning-assisted correction of correlated qubit errors in a topological codeMay 22 2017Jan 17 2018A fault-tolerant quantum computation requires an efficient means to detect and correct errors that accumulate in encoded quantum information. In the context of machine learning, neural networks are a promising new approach to quantum error correction. ... More

Adaptive weight estimator for quantum error correctionDec 06 2017Quantum error correction of a surface code or repetition code requires the pairwise matching of error events in a space-time graph of qubit measurements, such that the total weight of the matching is minimized. The input weights follow from a physical ... More

Fluctuation conductivity of disordered superconductors in magnetic fieldsMar 10 2013Jul 25 2013We calculate fluctuation corrections to the longitudinal conductivity of disordered superconductors subject to an external magnetic field. We derive analytic expressions that are valid in the entire metallic part of the temperature-magnetic field phase ... More

General method for extracting the quantum efficiency of dispersive qubit readout in circuit QEDNov 14 2017Apr 05 2018We present and demonstrate a general three-step method for extracting the quantum efficiency of dispersive qubit readout in circuit QED. We use active depletion of post-measurement photons and optimal integration weight functions on two quadratures to ... More

Engineering Hybrid Epitaxial InAsSb/Al Nanowire Materials for Stronger Topological ProtectionNov 18 2017Dec 29 2017The combination of strong spin-orbit coupling, large $g$-factors, and the coupling to a superconductor can be used to create a topologically protected state in a semiconductor nanowire. Here we report on growth and characterization of hybrid epitaxial ... More

Delocalizing transition of multidimensional solitons in Bose-Einstein condensatesJul 11 2003Critical behavior of solitonic waveforms of Bose-Einstein condensates in optical lattices (OL) has been studied in the framework of continuous mean-field equation. In 2D and 3D OLs bright matter-wave solitons undergo abrupt delocalization as the strength ... More

The relationship of time and spaceMar 29 2004We show that, in addition to radiation travelling at the speed of light, QED theory predicts a second type of radiation with an infinite velocity. We also show that charge, as it appears in the Dirac equation, may have a triune nature.

The energy density of an Ising half plane latticeNov 24 2010We compute the energy density at arbitrary temperature of the half plane Ising lattice with a boundary magnetic field $H_b$ at a distance $M$ rows from the boundary and compare limiting cases of the exact expression with recent calculations at $T=T_c$ ... More

On The Timescale Forcing in AstrobiologyDec 10 2007Dec 20 2007We investigate the effects of correlated global regulation mechanisms, especially Galactic gamma-ray bursts (GRBs), on the temporal distribution of hypothetical inhabited planets, using simple Monte Carlo numerical experiments. Starting with recently ... More

Variability of Fe II Emission Features in the Seyfert 1 Galaxy NGC 5548Feb 21 2005We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with those of the optical ... More

Top quark longitudinal polarization near the threshold in l+ l- annihilationFeb 03 1998Feb 05 1998We show that the longitudinal polarization of the top quarks produced in the annihilation of e+ e- or mu+ mu- into tbar t at energies near the threshold is not affected by the large Coulomb-type corrections, which greatly modify the total cross section. ... More

Renormalisation and hierarchiesJun 21 2004We describe a new method of calculating the renormalised energy of a field obeying the Maxwell and Dirac equations. The method does not involve evaluating integrals but relies instead on summing a geometric series. We show that the new solution is equivalent ... More

Compression-based SimilarityOct 20 2011First we consider pair-wise distances for literal objects consisting of finite binary files. These files are taken to contain all of their meaning, like genomes or books. The distances are based on compression of the objects concerned, normalized, and ... More

Open charm production in Double Parton Scattering processes in the forward kinematicsJul 29 2016We calculate the rate of double open charm production in the forward kinematics studied recently in the LHCb experiment. We find that the mean field approximation for the double parton GPD (Generalized parton distributions), which neglects parton - parton ... More

The Milagro anticenter hot spots: cosmic rays from the Geminga supernova ?Feb 15 2008May 29 2008The Milagro experiment has announced the discovery of an excess flux of TeV cosmic rays from the general direction of the heliotail, also close to the Galactic anticenter. We investigate the hypothesis that the excess cosmic rays were produced in the ... More

A high-accuracy algorithm for designing arbitrary holographic atom trapsDec 05 2007We report the realization of a new iterative Fourier-transform algorithm for creating holograms that can diffract light into an arbitrary two-dimensional intensity profile. We show that the predicted intensity distributions are smooth with a fractional ... More

Permutation statistics on involutionsDec 11 2004In this paper we look at polynomials arising from statistics on the classes of involutions, $I_n$, and involutions with no fixed points, $J_n$, in the symmetric group. Our results are motivated by F. Brenti's conjecture which states that the Eulerian ... More

The 2-dimensional non-linear sigma-model on a random laticeMar 27 1995Mar 28 1995The O(n) non-linear $\sigma$-model is simulated on 2-dimensional regular and random lattices. We use two different levels of randomness in the construction of the random lattices and give a detailed explanation of the geometry of such lattices. In the ... More

The logarithmic negativity: A full entanglement monotone that is not convexMay 10 2005Feb 28 2006It is proven that the logarithmic negativity does not increase on average under positive partial transpose preserving (PPT) operation including subselection (a set of operations that incorporate local operations and classical communication (LOCC) as a ... More

Speculative trading: the price multiplier effectOct 23 1999During a speculative episode the price of an item jumps from an initial level p_1 to a peak level p_2 before more or less returning to level p_1. The ratio p_2/p_1 is referred to as the amplitude A of the peak. This paper shows that for a given market ... More

Z_c(3900) - what is inside?Apr 01 2013The models for the internal structure of the newly found four-quark charmonium-like resonance $Z_c(3900)$ are discussed: the molecular model as well as the hadro-charmonium and tetraquark schemes. It is argued that it would be possible to resolve between ... More

CP Violation in Higgs Diphoton Decay in Models with Vectorlike Heavy FermionsAug 21 2012Aug 26 2012The amplitude of the diphoton decay of the Higgs boson is considered in an extension of the Standard Model involving heavy vectorlike fermions, which was recently suggested in the literature in order to explain a possible enhancement of the h -> gamma ... More

Isospin properties of the X state near the D {\bar D}^{*} thresholdApr 23 2007The $D {\bar D}^*$ scattering amplitude and the production of the final states $\pi^+ \pi^- J/\psi$ and $\pi^+ \pi^- \pi^0 J/\psi$ near the $D^0 {\bar D}^{*0}$ threshold are discussed following the recent suggestion that the observed peaks X(3872) and ... More

Remarks on the decays chi_{bJ}^\prime -> omega UpsilonApr 16 2003The recently observed by CLEO cascade decays Upsilon(3S) -> gamma chi_{bJ}^\prime -> gamma omega Upsilon are discussed. It is shown that within the nonrelativistic description of bottomonium in the heavy b quark limit, the ratio of the rates of the transitions ... More

The enhancement of the decay Upsilon(1D) -> eta Upsilon(1S) by the axial anomaly in QCDFeb 27 2003It is shown that the rates of the decays Upsilon(1^3D_1) -> eta Upsilon(1S) and Upsilon(1^3D_2) -> eta Upsilon(1S) should be comparable to and likely exceed that of the recently discussed in the literature two-pion transition Upsilon(1D) -> pi pi Upsilon(1S). ... More

Semiclassical suppression of black hole production in particle collisionsJul 10 2001It is argued that the cross section for production of large black holes, for which a semiclassical description is applicable, cannot be given by the geometric area of the black hole horizon, as claimed recently in the literature. Rather the production ... More

Spectator effects in semileptonic decay of charmed baryonsApr 16 1996Aug 02 1996It is shown that the absolute rate of the semileptonic decays of the $\Xi_c$ baryons can be as much as two times higher than the semileptonic decay rate of $\Lambda_c$ due to the Pauli interference of the strange quark. This interference effect is still ... More

Catalyzed decay of false vacuum in four dimensionsSep 07 1993The probability of destruction of a metastable vacuum state by the field of a highly virtual particle with energy $E$ is calculated for a (3+1) dimensional theory in the leading WKB approximation in the thin-wall limit. It is found that the induced nucleation ... More

The process $e^+e^- \to ππX(3823)$ in the soft pion limitApr 12 2015Apr 29 2015The production of the resonance $X(3823)$, identified as the charmonium $^3D_2$ state, in the process $e^+e^- \to \pi \pi X(3823)$ has been recently reported by BESIII. It is pointed out that this process is fully described, up to one overall coupling ... More

Enhanced mixing of partial waves near threshold for heavy meson pairs and properties of $Z_b(10610)$ and $Z_b(10650)$ resonancesJan 22 2013Feb 04 2013The mixing of $S-D$ partial waves for the heavy meson pairs in the decays $\Upsilon(5S) \to [B^* \bar B+ {\rm c.c.}] \pi$ and $\Upsilon(5S) \to B^* \bar B^* \pi$ is considered. It is argued that this mixing, enhanced by the heavy meson mass, is calculable ... More

Zeros of Tree-Level Amplitudes at Multi-Boson ThresholdsOct 19 1992Propagation of particles with emission of arbitrary number of identical bosons all being at rest is considered. It is shown that in certain models the tree-level amplitudes for production of $n$ scalar bosons by two incoming particles are all equal to ... More

Summing One-Loop Graphs at Multi-Particle ThresholdSep 15 1992It is shown that the technique recently suggested by Lowell Brown for summing the tree graphs at threshold can be extended to calculate the loop effects. Explicit result is derived for the sum of one-loop graphs for the amplitude of threshold production ... More

Confinement and center vortex dynamics in different gauge groupsOct 26 2006The random vortex world-surface model is extended to the gauge groups SU(4) and Sp(2). Compared to the SU(2) and SU(3) models studied previously, which reproduce the infrared properties of the corresponding Yang-Mills theories on the basis of a simple ... More

Z(2)-symmetric center vortex model with a first-order deconfinement transitionOct 14 2006A random vortex world-surface model for the infrared sector of Sp(2) Yang-Mills theory is constructed. The Sp(2) gauge group, while allowing for the same set of center vortex fluxes as the SU(2) gauge group, induces a significantly different dynamics ... More

Center vortex model for Sp(2) Yang-Mills theoryOct 11 2006Oct 17 2006The question whether the center vortex picture of the strongly interacting vacuum can encompass the infrared dynamics of both SU(2) as well as Sp(2) Yang-Mills theory is addressed. These two theories contain the same center vortex degrees of freedom, ... More

Gravitational radiation from elastic particle scattering in models with extra dimensionsDec 30 2005In this paper we derive a formula for the energy loss due to elastic N to N particle scattering in models with extra dimensions that are compactified on a radius R. In contrast to a previous derivation we also calculate additional terms that are suppressed ... More

SU(N) gauge theories in four dimensions: exploring the approach to N = infinityMar 23 2001Jun 27 2001We calculate the string tension, K, and some of the lightest glueball masses, M, in 3+1 dimensional SU(N) lattice gauge theories for N=2,3,4,5 . From the continuum extrapolation of the lattice values, we find that the mass ratios, M/sqrt(K), appear to ... More

DIFFRACTION EFFECTS IN MICROLENSING OF Q2237+0305Mar 10 1995Geometrical optics provides an excellent description for quasar images crossing caustics which are formed by gravitational microlensing of objects like Q2237+0305. Within this approximation the source size can be estimated from the maximum magnification ... More

Quantum and classical statistics of the electromagnetic zero-point fieldJun 16 2001A classical electromagnetic zero-point field (ZPF) analogue of the vacuum of quantum field theory has formed the basis for theoretical investigations in the discipline known as random or stochastic electrodynamics (SED) wherein quantum measurements are ... More

Magnetization of concentrated polydisperse ferrofluids: Cluster expansionSep 04 2006The equilibrium magnetization of concentrated ferrofluids described by a system of polydisperse dipolar hard spheres is calculated as a function of the internal magnetic field using the Born--Mayer or cluster expansion technique. This paper extends the ... More

Four-loop free energy for the 2D O(n) nonlinear sigma-model with 0-loop and 1-loop Symanzik improved actionsJun 16 1999Jan 25 2000We calculate up to four loops the free energy of the two-dimensional (2D) O(n) nonlinear sigma-model regularized on the lattice with the 0-loop and 1-loop Symanzik improved actions. An effective coupling constant based on this calculation is defined.

The stellar correlation function from SDSS - A statistical search for wide binary starsJan 21 2010Jan 28 2010We study the statistical properties of the wide binary population in the Galaxy field with projected separations larger than 200 AU by constructing the stellar angular two-point correlation function (2PCF) from a homogeneous sample of nearly 670'000 main ... More

The Klein-Gordon and the Dirac oscillators in a noncommutative spaceDec 13 2004We study the Dirac and the klein-Gordon oscillators in a noncommutative space. It is shown that the Klein-Gordon oscillator in a noncommutative space has a similar behaviour to the dynamics of a particle in a commutative space and in a constant magnetic ... More

On the foundations of the classical relativistic theory of the field of an accelerated extended chargeJun 13 2014The effect of nonzero extent of an electric charge is considered within the assumption that the structure of the charge at rest is spherically-symmetric and the current vector is linear in the acceleration.

Notes on Some Questions in Mathematical Physics and Quantum InformationApr 16 2014This is a set of notes on some unrelated topics in mathematical physics, at varying levels of detail. First, I consider certain questions relating to the decay of correlation functions in matrix product states, in particular those generated by quantum ... More

Matrix Product Operators and Central Elements: Classical Description of a Quantum StateJul 06 2012Sep 10 2013We study planar two-dimensional quantum systems on a lattice whose Hamiltonian is a sum of local commuting projectors of bounded range. We consider whether or not such a system has a zero energy ground state. To do this, we consider the problem as a one-dimensional ... More

Decay of Correlations in Fermi Systems at Non-zero TemperatureJun 16 2004The locality of correlation functions is considered for Fermi systems at non-zero temperature. We show that for all short-range, lattice Hamiltonians, the correlation function of any two fermionic operators decays exponentially with a correlation length ... More

Mean-Field and Anomalous Behavior on a Small-World NetworkApr 23 2003May 01 2003We use scaling results to identify the crossover to mean-field behavior of equilibrium statistical mechanics models on a variant of the small world network. The results are generalizable to a wide-range of equilibrium systems. Anomalous scaling is found ... More

Effective Gauge Theories of Spin SystemsNov 07 2000Nov 09 2000A large variety of microscopic gauge theories can be written for antiferromagnetic spin systems, including $U(1), SU(2)$, and $Z_N$. I consider the question of the appropriate effective gauge theory for such systems. I show that while an SU(N) anti-ferromagnet ... More

Bose Glass in Large N Commensurate Dirty Boson ModelNov 09 1998The large N commensurate dirty boson model, in both the weakly and strongly commensurate cases, is considered via a perturbative renormalization group treatment. In the weakly commensurate case, there exists a fixed line under RG flow, with varying amounts ... More

Sufficient Conditions for Topological Order in InsulatorsNov 04 2004Jun 02 2005We prove the existence of low energy excitations in insulating systems at general filling factor under certain conditions, and discuss in which cases these may be identified as topological excitations. This proof is based on previously proven locality ... More

Dirac, Anderson, and Goldstone on the KagomeMay 23 2000Jun 18 2000We show that there exists a long-range RVB state for the kagome lattice spin-1/2 Heisenberg antiferromagnet for which the spinons have a massless Dirac spectrum. By considering various perturbations of the RVB state which give mass to the fermions by ... More

The constituent quark as a soliton in a linear sigma-modelOct 30 1996We study a stable, soliton-like solution in the linear $\sigma$-model where the chiral fields are coupled to a single massless nonstrange quark. We investigate a possibility that this solution represents the constituent quark of Georgi and Manohar. We ... More

Sub-Microarcsecond Astrometry with SIM-Lite: A Testbed-based Performance AssessmentDec 08 2008SIM-Lite is an astrometric interferometer being designed for sub-microarcsecond astrometry, with a wide range of applications from searches for Earth-analogs to determining the distribution of dark matter. SIM-Lite measurements can be limited by random ... More

Implementation of an all-electron GW Approximation using the Projector Augmented Wave method: I. Formulation and application to the electronic structure of semiconductorsNov 19 1999Dec 06 1999We have implemented the so called GW approximation (GWA) based on an all-electron full-potential Projector Augmented Wave (PAW) method. For the screening of the Coulomb interaction W we tested three different plasmon-pole dielectric function models, and ... More

Light Quark Spin Symmetry in $Z_b$ Resonances?Jan 11 2016It is argued that the recent Belle data, consistent with no activity in the spectrum of the $B^* \bar B + B \bar B^*$ pairs at the mass of the $Z_b(10650)$ resonance, imply that the part of the interaction between heavy mesons that depends on the total ... More

Twist-Deformed Supersymmetries in Non-Anticommutative SuperspacesJun 04 2005Oct 11 2005We consider a quantum group interpretation of the non-anticommutative deformations in Euclidean supersymmetric theories. Twist deformations in the corresponding superspaces and Lie superalgebras are constructed in terms of the left supersymmetry generators. ... More

Short harmonic superfields and light-cone gauge in super-Yang-Mills equationsNov 02 2000We analyze the superfield equations of the 4-dimensional N=2 and N=4 SYM-theories using light-cone gauge conditions and the harmonic-superspace approach. The harmonic superfield equations of motion are drastically simplified in this gauge, in particular, ... More

Harmonic Superspaces For Three-Dimensional TheoriesApr 27 1998Three-dimensional field theories with N=3 and N=4 supersymmetries are considered in the framework of the harmonic-superspace approach. Analytic superspaces of these supersymmetries are similar; however, the geometry of gauge theories with the manifest ... More

N=4 Multiplets in N=3 Harmonic SuperspaceAug 29 2003It is shown that the N=3 harmonic-superfield equations of motion are invariant with respect to the 4-th supersymmetry. The SU(3) harmonics are also used to analyze a more flexible form of superfield constraints for the Abelian N=4 vector multiplet and ... More

N=4 Super-Yang-Mills Equations In Harmonic SuperspaceApr 12 2001Apr 13 2001We analyze the superfield equations of the 4-dimensional N=4 SYM-theory using light-cone gauge conditions and the harmonic-superspace approach. The harmonic superfield equations of motion are drastically simplified in this gauge, in particular, the basic ... More

Quantum Deformations of the Self-Duality Equation and Conformal TwistorsSep 12 1995A noncommutative algebra of the complex $q$-twistors and their differentials is considered on the basis of the quantum $GL_q (4)\times SL_q (2)$ group. Real and pseudoreal $q$-twistors are discussed too. We consider the quantum-group self-duality equation ... More

The Rule of Discarding $1/N_c$ in Inclusive Weak DecaysJul 14 1992Jul 17 1992We continue to investigate the effects of the (dominant) subleading operator of the $\vec\sigma\vec H$ type in the $1/N_c$ parts of the weak nonleptonic amplitudes. If the previous work concentrated on exclusive decays now we analyse inclusive widths ... More

Quantum Fields on Star GraphsMay 03 2006We construct canonical quantum fields which propagate on a star graph modeling a quantum wire. The construction uses a deformation of the algebra of canonical commutation relations, encoding the interaction in the vertex of the graph. We discuss in this ... More

Stability of the essential spectrum for 2D--transport models with Maxwell boundary conditionsApr 04 2005We discuss the spectral properties of collisional semigroups associated to various models from transport theory by exploiting the links between the so-called resolvent approach and the semigroup approach. Precisely, we show that the essential spectrum ... More

Universal eigenvector statistics in a quantum scattering ensembleDec 04 2000We calculate eigenvector statistics in an ensemble of non-Hermitian matrices describing open quantum systems [F. Haake et al., Z. Phys. B 88, 359 (1992)] in the limit of large matrix size. We show that ensemble-averaged eigenvector correlations corresponding ... More

Collective versus single-particle effects in the optical spectra of finite electronic quantum systemsNov 19 2000We study optical spectra of finite electronic quantum systems at frequencies smaller than the plasma frequency using a quasi-classical approach. This approach includes collective effects and enables us to analyze how the nature of the (single-particle) ... More

Absorption of radiation by small metallic particles: a general self-consistent approachJul 21 1999We introduce a theory for the absorption of electromagnetic radiation by small metal particles, which generalises the random phase approximation by incorporating both electric and magnetic dipole absorption within a unified self-consistent scheme. We ... More

Diffusion-Reorganized Aggregates: Attractors in Diffusion Processes?Oct 27 2000A process based on particle evaporation, diffusion and redeposition is applied iteratively to a two-dimensional object of arbitrary shape. The evolution spontaneously transforms the object morphology, converging to branched structures. Independently of ... More

Irrational Conformal Field Theory on the Sphere and the TorusNov 29 1994Nov 30 1994I review the foundations of irrational conformal field theory (ICFT), which includes rational conformal field theory as a small subspace. Highlights of the review include the Virasoro master equation and the generalized Knizhnik-Zamolodchikov equations ... More

Rigorous Solution of the Gardner ProblemDec 03 2001We prove rigorously the well-known result of Gardner about the typical fractional volume of interactions between N spins which solve the problem of storing a given set of random patterns. The Gardner formula for this volume in the limit N,p \to \infty, ... More

Open charm production in Double Parton Scattering processes in the forward kinematicsJul 29 2016Nov 28 2016We calculate the rate of double open charm production in the forward kinematics studied recently in the LHCb experiment. We find that the mean field approximation for the double parton GPD (Generalized parton distributions), which neglects parton - parton ... More

Risk and Machine Protection for Stored Magnetic and Beam EnergiesJul 06 2016Risk is a fundamental consideration when designing electronic systems. For most systems a view of risk can assist in setting design objectives, whereas both a qualitative and quantitative understanding of risk is mandatory when considering protection ... More

The Binary Zoo: The Calculation of Production Rates of Binaries Through 2+1 Encounters in Globular ClustersJul 07 1995In studying encounters between binaries and single stars, one is interested in three classes of events: exchanges of stars, hardening of the original binary by a third star, and the production of merged objects. We present a means for computing cross ... More

Quasi-free photoproduction of pion-pairs off protons and neutronsJan 29 2014Beam-helicity asymmetries and mass-differential cross sections have been measured at the MAMI accelerator in Mainz for the photoproduction of neutral and mixed-charge pion pairs in the reactions $\boldsymbol{\gamma}p\rightarrow n\pi^0\pi^+$ and $\boldsymbol{\gamma}p\rightarrow ... More

The Foldy Wouthuysen and scattering matrix method for calculating the transmission of electrons through two dimensional graphene: electrons like lightOct 30 2016Nov 27 2016In this paper is provided a novel approach to solving the transmission of electrons through graphene, which is shown to be accurate both at high and low speeds. The Dirac equation is scalarised using the Foldy Wouthuysen expansion approximation [1], to ... More

Doppler Boosting May Have Played No Significant Role in the Finding Surveys of Radio-Loud QuasarsDec 22 2011There appears to be a fundamental problem facing Active Galactic Nuclei jet models that require highly relativistic ejection speeds and small jet viewing angles to explain the large apparent superluminal motions seen in so many of the radio-loud quasars ... More

Distances of Quasars and Quasar-Like Galaxies: Further Evidence that QSOs may be Ejected from Active GalaxiesSep 01 2004If high-redshift QSOs are ejected from the nuclei of low-redshift galaxies, as some have claimed, a large portion of their redshift must be intrinsic (non-Doppler). If these intrinsic components have preferred values, redshifts will tend to cluster around ... More

On QSO Distances and Lifetimes in a Local ModelDec 03 2001It was previously shown from the redshifts and positions of the compact, high-redshift objects near the Seyfert galaxy NGC 1068 that they appear to have been ejected from the center of the galaxy in at least four similarly structured triplets. Here some ... More

Weight Reduction for Quantum CodesNov 11 2016We present an algorithm that takes a CSS stabilizer code as input, and outputs another CSS stabilizer code such that the stabilizer generators all have weights $O(1)$ and such that $O(1)$ generators act on any given qubit. The number of logical qubits ... More

Investigating the Consistency of Stellar Evolution Models with Globular Cluster Observations via the Red Giant Branch BumpOct 26 2015Synthetic RGBB magnitudes are generated with the most recent theoretical stellar evolution models computed with the Dartmouth Stellar Evolution Program (DSEP) code. They are compared to the observational work of Nataf et al., who present RGBB magnitudes ... More

Modeling the Lunar plasma wakeJan 02 2013Bodies that lack a significant atmosphere and internal magnetic fields, such as the Moon and asteroids, can to a first approximation be considered passive absorbers of the solar wind. The solar wind ions and electrons directly impact the surface of these ... More

Simply Modeling B -> K* gammaAug 20 1993A simple relativistic model of heavy-light mesons is applied to the rare decay B -> K* gamma in the standard model. We find Gamma(B -> K* gamma)/Gamma(b -> s gamma)=(17 \pm 4)% and BR(B -> K* gamma)=(4.8 \pm 1.9) \times 10^{-5}(V_cb/.04)^2. These numbers ... More

Simply Modeling Meson HQETNov 06 1992Oct 21 1994A simple relativistic model of heavy-quark-light-quark mesons is proposed. In an expansion in inverse powers of the heavy quark mass we find that all zeroth and first order heavy quark symmetry relations are satisfied. The main results are: - the difference ... More

Para-Hopf algebroids and their cyclic cohomologyMay 11 2001Sep 08 2004We introduce the concept of {\it para-Hopf algebroid} and define their cyclic cohomology in the spirit of Connes-Moscovici cyclic cohomology for Hopf algebras. Para-Hopf algebroids are closely related to, but different from, Hopf algebroids. Their definition ... More

A New Cyclic Module for Hopf AlgebrasOct 15 2000Jun 07 2002We define a new cyclic module, dual to the Connes-Moscovici cyclic module, for Hopf algebras, and give a characteristric map for the coaction of Hopf algebras. We also compute the resulting cyclic homology for cocommutative Hopf algebras, and some quantum ... More

Special elements in lattices of semigroup varietiesSep 01 2013May 25 2015We observe results concerning special elements of eight types (modular, lower-modular, upper-modular, distributive, codistributive, standard, costandard and neutral elements) in the lattice of all semigroup varieties and three its sublattices, namely, ... More

Fractional statistics of topological defects in graphene and related structuresSep 26 2007We show that fractional charges bound to topological defects in the recently proposed time-reversal-invariant models on honeycomb and square lattices obey fractional statistics. The effective low-energy description is given in terms of a `doubled' level-2 ... More

A Note on Cyclic Duality and Hopf AlgebrasOct 07 2003We show that various cyclic and cocyclic modules attached to Hopf algebras and Hopf modules are related to each other via Connes' duality isomorphism for the cyclic category.