Results for "J. Bookbinder"

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The International X-ray Observatory - RFI#1Jan 13 2010The International X-ray Observatory (IXO), a joint NASA-ESA-JAXA effort, will address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What ... More
The International X-ray Observatory - RFI#2Mar 15 2010The International X-ray Observatory (IXO) is a joint NASA-ESA-JAXA effort. X-ray observations will resolve pressing astrophysical questions such as: What happens close to a black hole? How do supermassive black holes grow? How does large scale structure ... More
The Solar Spectroscopy Explorer MissionNov 17 2010The Solar Spectroscopy Explorer (SSE) concept is conceived as a scalable mission, with two to four instruments and a strong focus on coronal spectroscopy. In its core configuration it is a small strategic mission ($250-500M) built around a microcalorimeter ... More
HST Images of the Eclipsing Pulsar B1957+20Feb 19 1995We have obtained images of the eclipsing pulsar binary PSR~B1957+20 using the Planetary Camera of the Hubble Space Telescope. The high spatial resolution of this instrument has allowed us to separate the pulsar system from a nearby background star which ... More
[Plasma 2020 Decadal] Multipoint Measurements of the Solar Wind: A Proposed Advance for Studying Magnetized TurbulenceMar 13 2019A multi-institutional, multi-national science team will soon submit a NASA proposal to build a constellation of spacecraft to fly into the near-Earth solar wind in a swarm spanning a multitude of scales in order to obtain critically needed measurements ... More
International X-ray Observatory (IXO) Assessment Study Report for the ESA Cosmic Vision 2015-2025Feb 14 2011The International X-Ray Observatory (IXO) will address fundamental questions in astrophysics, including "When did the first SMBH form? How does large scale structure evolve? What happens close to a black hole? What is the connection between these processes? ... More
The Extreme Physics ExplorerDec 06 2011A non-proprietary Mission Concept available for presentation to NASA, providing High Area, High Resolution Imaging Spectroscopy and Timing with Arcmin Angular Resolution Submitted in response to NASA 2011 RFI NNH11ZDA018L 'Concepts for the Next NASA X-ray ... More
Aesthetics and Astronomy: Studying the public's perception and understanding of non-traditional imagery from spaceSep 03 2010Some 400 years after Galileo, modern telescopes have enabled humanity to "see" what the natural eye cannot. Astronomical images today contain information about incredibly large objects located across vast distances and reveal information found in "invisible" ... More
Examining Perceptions of Astronomy Images Across Mobile PlatformsMar 23 2014Modern society has led many people to become consumers of data unlike previous generations. How this shift in the way information is communicated and received - including in areas of science - and affects perception and comprehension is still an open ... More
Temperature and Emission-Measure Profiles Along Long-Lived Solar Coronal Loops Observed with TRACEMar 31 1999We report an initial study of temperature and emission measure distributions along four steady loops observed with the Transition Region and Coronal Explorer (TRACE) at the limb of the Sun. The temperature diagnostic is the filter ratio of the extreme-ultraviolet ... More
The International X-ray ObservatoryJan 16 2010The International X-ray Observatory (IXO) is a joint ESA-JAXA-NASA effort to address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What ... More
Science Objectives for an X-Ray Microcalorimeter Observing the SunNov 17 2010We present the science case for a broadband X-ray imager with high-resolution spectroscopy, including simulations of X-ray spectral diagnostics of both active regions and solar flares. This is part of a trilogy of white papers discussing science, instrument ... More
The 3-D composition of the Galactic interstellar medium. The hot phases and X-ray absorbing materialNov 19 2002We present maps of the Galactic X-ray Halo and constrain the location of X-ray absorbing gas using the X-ray radiation transfer as distance a indicator. Based on a consistent model of the soft X-ray background (SXRB) and the ROSAT all-sky survey, we derive ... More
Collisions of solid ice in planetesimal formationJan 18 2016We present collision experiments of centimetre projectiles on to decimetre targets, both made up of solid ice, at velocities of $15\,\mathrm{m\,s^{-1}}$ to $45\,\mathrm{m\,s^{-1}}$ at an average temperature of $\mathrm{T_{avg}}=255.8\pm0.7\,\mathrm{K}$. ... More
A model realisation of the Jaffe-Wilczek correlation for pentaquarksMar 22 2004We discuss a realisation of the pentaquark structure proposed by Jaffe and Wilczek within a simple quark model with colour-spin contact interactions and coloured harmonic confinement, which accurately describes the $\Delta-N$ splitting. In this model ... More
Recoil Polarization Measurements for Neutral Pion Electroproduction at Q^2=1 (GeV/c)^2 Near the Delta ResonanceSep 01 2005We measured angular distributions of differential cross section, beam analyzing power, and recoil polarization for neutral pion electroproduction at Q^2 = 1.0 (GeV/c)^2 in 10 bins of W across the Delta resonance. A total of 16 independent response functions ... More
Accuracy of traditional Legendre estimators of quadrupole ratios for the N to Delta transitionJul 06 2005We evaluate the accuracy of traditional estimators often used to extract N to Delta quadrupole ratios from cross section angular distributions for pion electroproduction. We find that neither M1+ dominance nor sp truncation is sufficiently accurate for ... More
Time-odd components in the mean field of rotating superdeformed nucleiFeb 10 1995Rotation-induced time-odd components in the nuclear mean field are analyzed using the Hartree-Fock cranking approach with effective interactions SIII, SkM*, and SkP. Identical dynamical moments ${{\cal J}^{(2)}}$ are obtained for pairs of superdeformed ... More
Time-odd components in the rotating mean field and identical bandsOct 04 1995A systematic construction of the energy-density functional within the local density approximation is presented. The Hartree-Fock equations corresponding to such a functional are solved in case of rotating superdeformed nuclei. The identical bands in $^{152}$Dy, ... More
On the shape of attractors of discrete dynamical systemsNov 20 2015Let $M$ be a manifold or (more generally) a locally compact, metrizable ANR. If $K$ is an attractor for a flow in $M$, with basin of attraction $\mathcal{A}(K)$, it is well known that the inclusion $i : K \subseteq \mathcal{A}(K)$ is always a shape equivalence. ... More
Low Temperature Properties of Finite Dimensional Ising Spin Glasses : (some) Numerical SimulationsJun 26 2003Jul 21 2003We review some recent results on finite dimensional spin glasses by studying recent numerical simulations and their relationship with experiments. In particular we will show results obtained at zero and non zero temperature, focusing in the low temperature ... More
Vortex lattices in strong type-II superconducting two-dimensional stripsOct 03 1997May 11 1998We show how to calculate semi-analytically the dense vortex state in strong type-II superconducting nanostructures. For the specific case of a strip, we find vortex lattice solutions which also incorporate surface superconductivity. We calculate the energy ... More
Hamiltonian study of Supersymmetric Yang-Mills Quantum MechanicsAug 28 2002New results obtained within the recently developed approach to supersymmetric quantum mechanical systems are presented. The method does not suffer from the sign problem in any dimensions and is capable to provide any quantum observable with controllable ... More
Excited-State Density Distributions of Neutron-Rich Unstable NucleiAug 02 2006We calculate densities of excited states in the quasiparticle random-phase approximation (QRPA)with Skyrme interactions and volume pairing. We focus on low-energy peaks/bumps in the strength functions of a range of Ca, Ni, and Sn isotopes for J pi = 0+, ... More
The circumstellar environment of rotating Wolf-Rayet Stars and the implications for GRB afterglowsOct 13 2006If Wolf-Rayet stars are the progenitors of Gamma-ray bursts (GRBs), they must rotate rapidly to produce the GRB. This rotation may effect their stellar-wind bubbles and possibly explain why so many GRB afterglows occur in a constant density medium.
Massive binaries, Wolf-Rayet stars and supernova progenitorsDec 17 2006Binary stars are important for a full understanding of stellar evolution. We present a summary of how predictions of the relative supernova rates varies between single and binary stars. We also show how the parameter space of different supernova types ... More
The Metallicity of Galaxy Disks: Infall versus OutflowAug 28 2006Both gas accretion (infall) and winds (outflow) change a galaxy's metallicity and gas fraction, lowering the effective yield. Low effective yields in galaxies with rotation speeds < 120 km/s have been widely interpreted as the onset of SN-driven winds ... More
Exploring high-density baryonic matter: Maximum freeze-out densityMay 18 2009Jan 21 2016The hadronic freeze-out line is calculated in terms of the net baryon density and the energy density instead of the usual T and mu_B. This analysis makes it apparent that the freeze-out density exhibits a maximum as the collision energy is decreased. ... More
Effects of Spin-Isospin Modes in Transport SimulationsMay 12 1997In-medium properties derived for nuclear matter in a microscopic pi + nucleon-hole + delta-hole model are incorporated into transport simulations of nuclear collisions by means of a local-density approximation and by utilizing a local medium frame. Certain ... More
Spin-Isospin Modes in Heavy-Ion Collisions I: Nuclear Matter at Finite TemperaturesDec 14 1994With a view towards implementation in microscopic transport simulations of heavy-ion collisions, the properties of spin-isospin modes are studied in nuclear matter consisting of nucleons and Delta isobars that interact by the exchange of pi and rho mesons. ... More
Testing limits of statistical hadronizationSep 26 2002Much of the energy of the nuclei colliding at RHIC or SPS is converted into final state hadronic particles. About a quarter of this energy is in baryons and antibaryons. There are nearly 10 strange quark pairs per central rapidity participant. Do we really ... More
On Conditions Relating to NonsolvabilitySep 22 2011Recent work of Kaplan and Levy refining a nonsolvability criterion proved by Thompson in his N-Groups paper prompts questions on whether certain conditions on groups are equivalent to nonsolvability.
Progress in nonequilibrium quantum field theory IIOct 25 2004We review recent developments for the description of nonequilibrium quantum fields, continuing hep-ph/0302210.
Progress in Nonequilibrium Quantum Field TheoryFeb 24 2003We review recent developments for the description of far-from-equilibrium dynamics of quantum fields and subsequent thermalization.
Holophotography with a diffraction gratingMar 28 2007Color encoding of depth is shown to occur naturally in images of objects observed through diffraction gratings under common white light illumination. A synthetic image is then obtained from a single point of view, a phenomenon that can be applied to stereophotography. ... More
Optica Precolombina Del PeruFeb 02 2007Archaeological American mirrors are common findings and the images obtained with them are often described by archaeologists as possessing high quality. However, photographs attesting this fact are rare, if any. To the best of my knowledge, only two papers ... More
The use of diffractive screens for electronic imagingSep 27 2006Diffractive screens are high-resolution elements with capability for generating holographic-like images from a sequence of planes where TV frames are seen oblique to it. If we project a sequence of contour lines of an object it could be seen in continuous ... More
La Nube: La Manera Mas Emocionante De Experimentar Espejos PlanosSep 29 2009Nov 03 2009ESPANOL: Una experiencia que parte del uso de un espejo plano colocado horizontalmente a la altura de la nariz del observador, que permite uma nueva dimension a la experiencia de ver imagenes com espejos simples, sirve para discutir lo que aun puede hacerse ... More
Olmec mirrors: an example of archaeological American mirrorsJan 30 2007Archaeological mirrors from the Olmec civilization are described according to bibliographic references and to personal observations and photographs.
New Exclusion Limits on Dark Gauge Forces from Proton Bremsstrahlung in Beam-Dump DataNov 15 2013We re-analyze published proton beam dump data taken at the U70 accelerator at IHEP Serpukhov with the $\nu$-calorimeter I experiment in 1989 to set mass-coupling limits for dark gauge forces. The corresponding data have been used for axion and light Higgs ... More
On gluon masses, colour symmetry, and a possible massive ninth gluonJun 13 1996Gluons acquire a determinate mass from quark loop radiative corrrections and self-interaction, when these are recomputed with the symmetrical theory of generalised functions. The colour symmetry may be~$U(3)$ instead of~$SU(3)$. The symmetry breaks spontaneously ... More
Nonperturbative SUSY Correlators at Finite TemperatureMar 16 1998We calculate finite temperature effects on a correlation function in the two dimensional supersymmetric nonlinear O(3) sigma model. The correlation function violates chiral symmetry and at zero temperature it has been shown to be a constant, which gives ... More
ON THE ORIGIN OF KALUZA-KLEIN STRUCTUREJun 07 1995It is suggested that quantum fluctuations of the light cone are at the origin of what appears at low energy to be a higher-dimensional structure over space-time. A model is presented which has but a finite number of Yang-Mills fields although the supplementary ... More
Exact trimer ground states on a spin-1 chainOct 22 1999We construct a new spin-1 model on a chain. Its ground state is determined exactly which is three-fold degenerate by breaking translational invariance. Thus we have trimerization. Excited states cannot be obtained exactly, but we determine a few low-lying ... More
Stability of Large Flocks: an ExampleFeb 03 2010Feb 09 2010The movement of a flock with a single leader (and a directed path from it to every agent) can be stabilized. Nonetheless for large flocks perturbations in the movement of the leader may grow to a considerable size as they propagate throughout the flock ... More
Extended Lyman-alpha emission from cold accretion streamsDec 19 2011Mar 07 2012{Abridged} We investigate the observability of cold accretion streams at redshift 3 via Lyman-alpha (Lya) emission and the feasibility of cold accretion as the main driver of Lya blobs (LABs). We run cosmological zoom simulations focusing on 3 halos spanning ... More
From single-shot towards general work extraction in a quantum thermodynamic frameworkApr 20 2015Jun 30 2015This paper considers work extraction from a quantum system to a work storage system (or weight) following reference [1]. An alternative approach is here developed that relies on the comparison of subspace dimensions without a need to introduce thermo-majorisation ... More
Method 2 at NLOMay 27 2004This note describes a theoretical study of Wbb and Wjj final states at the Tevatron using the NLO program MCFM. We extensively study the effect of NLO corrections with respect to variations of input parameters such as the minimum jet p_T and the choice ... More
Modular Invariants and Generalized Halphen SystemsFeb 17 1999Generalized Halphen systems are solved in terms of functions that uniformize genus zero Riemann surfaces, with automorphism groups that are commensurable with the modular group. Rational maps relating these functions imply subgroup relations between their ... More
Modular Solutions to Equations of Generalized Halphen TypeApr 09 1998Apr 28 1998Solutions to a class of differential systems that generalize the Halphen system are determined in terms of automorphic functions whose groups are commensurable with the modular group. These functions all uniformize Riemann surfaces of genus zero and have ... More
Collinear Points in PermutationsAug 29 2004Consider the following problem: how many collinear triples of points must a transversal of (Z/nZ)^2 have? This question is connected with venerable issues in discrete geometry. We show that the answer, for n prime, is between (n-1)/4 and (n-1)/2, and ... More
Detecting companions to extrasolar planets using mutual eventsMar 23 2007We investigate a new approach to the detection of companions to extrasolar planets beyond the transit method. We discuss the possibility of the existence of binary planets. We develop a method based on the imaging of a planet-companion as an unresolved ... More
A mathematical derivation of zero-temperature 2D superconductivity from microscopic Bardeen-Cooper-Schrieffer modelFeb 06 2019Starting from H. Fr\"ohlich's second-quantized Hamiltonian for a $d$-dimensional electron gas in interaction with lattice phonons describing the quantum vibrations of a metal, we present a rigorous mathematical derivation of the superconducting state, ... More
CCM Calculations For The Ground-State Properties Of The One-Dimensional Spin-Half $J_1$--$J_2$ Model: Possible Evidence of Collinear Ordering for $J_2/J_1 > \frac 12$?Mar 07 2011In this article we investigate the linear-chain spin-half $J_1$--$J_2$ model by using high-order coupled cluster method (CCM) calculations. We employ three model states, namely, a nearest-neighbour (n.n.) N\'eel model state in which neighbouring spins ... More
On the set of wild points of attracting surfaces in $\mathbb{R}^3$Mar 18 2016Suppose that a closed surface $S \subseteq \mathbb{R}^3$ is an attractor, not necessarily global, for a discrete dynamical system. Assuming that its set of wild points $W$ is totally disconnected, we prove that (up to an ambient homeomorphism) it has ... More
Limit Set of Trajectories of the Coupled Viscous Burgers' EquationsJul 29 1996In this letter, a coupled system of viscous Burgers' equations with zero Dirichlet boundary conditions and appropriate initial data is considered. For the well-known single viscous Burgers' equation with zero Dirichlet boundary conditions, the zero equilibrium ... More
Admissibility, stable units and connected componentsDec 19 2011Consider a reflection from a finitely-complete category $\mathbb{C}$ into its full subcategory $\mathbb{M}$, with unit $\eta :1_\mathbb{C}\rightarrow HI$. Suppose there is a left-exact functor $U$ into the category of sets, such that $UH$ reflects isomorphisms ... More
Metastability and paramagnetism in superconducting mesoscopic disksAug 24 1999Dec 22 1999A projected order parameter is used to calculate, not only local minima of the Ginzburg-Landau energy functional, but also saddle points or energy barriers responsible for the metastabilities observed in superconducting mesoscopic disks (Geim et al. Nature ... More
Absence of pairing in atomic Fermi gasesMay 11 2010May 18 2010Some thoughts regarding pairing in atomic Fermi gases were considered, meant for starting discussion on the topic.
Applications harmoniques et hyperbolicité des domaines tubesOct 26 2006An application of the Zalcman renormalization theorem to harmonic functions shows that the limit functions are nonconstant affine. Extensions of this method are given for maps with values in a torus or in a complex Lie groups. As an application, we give ... More
Massive stars in their death-throesSep 07 2008Sep 11 2008The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently there are 8 detected ... More
Testing Skyrme energy-density functionals with the QRPA in low-lying vibrational states of rare-earth nucleiMay 19 2011Although nuclear energy density functionals are determined primarily by fitting to ground state properties, they are often applied in nuclear astrophysics to excited states, usually through the quasiparticle random phase approximation (QRPA). Here we ... More
Self-consistent description of multipole strength: systematic calculationsMar 26 2006We use the quasiparticle random phase approximation with a few Skyrme density functionals to calculate strength functions in the Jpi = 0+, 1-, and 2+ channels for even Ca, Ni, and Sn isotopes, from the proton drip line to the neutron drip line. We show ... More
A Plasma Instability Theory of Gamma-Ray Burst EmissionApr 02 1999A plasma instability theory is presented for the prompt radiation from gamma-ray bursts. In the theory, a highly relativistic shell interacts with the interstellar medium through the filamentation and the two-stream instabilities to convert bulk kinetic ... More
Optical linewidth of a low density Fermi-Dirac gasFeb 11 1999We study propagation of light in a Fermi-Dirac gas at zero temperature. We analytically obtain the leading density correction to the optical linewidth. This correction is a direct consequence of the quantum statistical correlations of atomic positions ... More
Three-dimensional photography by holographyMar 22 2007Color encoding of depth is shown to occur naturally in holograms that are reconstructed under white light illumination. It can be registered in a common color photograph, allowing a simple method of visual decoding by means of ordinary colored 3-D spectacles. ... More
Asymptotic step profiles from a nonlinear growth equation for vicinal surfacesMay 23 2000Aug 28 2000We study a recently proposed nonlinear evolution equation describing the collective step meander on a vicinal surface subject to the Bales-Zangwill growth instability [O. Pierre-Louis et al., Phys. Rev. Lett. (80), 4221 (1998)]. A careful numerical analysis ... More
Asymmetric particle systems on RSep 02 1999Dec 22 1999We study interacting particle systems on the real line which generalize the Hammersley process [D. Aldous and P. Diaconis, Prob. Theory Relat. Fields 103, 199-213 (1995)]. Particles jump to the right to a randomly chosen point between their previous position ... More
Improved description of charged Higgs boson production at hadron collidersSep 08 2004Jan 13 2005We present a new method for matching the two twin-processes gb->H+/-t and gg->H+/-tb in Monte Carlo event generators. The matching is done by defining a double-counting term, which is used to generate events that are subtracted from the sum of these two ... More
Virtual photon structure from jet productionJul 08 1997Some aspects of extracting the information on the structure of virtual photons from jet production in ep and e^+e^- collisions are discussed.
Virtual Photon Structure from Jet Production at HERANov 21 1996The feasibility of measuring parton distribution functions of of virtual photons via the jet production at HERA is investigated.
Numeration-automatic sequencesMay 17 2006We present a base class of automata that induce a numeration system and we give an algorithm to give the n-th word in the language of the automaton when the expansion of n in the induced numeration system is feeded to the automaton. Furthermore we give ... More
Generating conjecture and Einstein-Maxwell field of plane symmetryApr 10 2000For the plane symmetry we have found the electro-vacuum exact solutions of the Einstein-Maxwell equations and we have shown that one of them is equivalent to the McVittie solution of a charged infinite thin plane. The analytical extension has been accomplished ... More
Interaction of antiproton with nucleiFeb 19 2015We performed fully self-consistent calculations of $\bar{p}$-nuclear bound states within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{p}$-meson coupling constants were adjusted to yield potentials consistent with $\bar{p}$-atom ... More
2 and 3-point functions in the ENJL-modelSep 06 1994We discuss the extended Nambu-Jona-Lasinio model as a low energy expansion, all two-point functions and an example of a three-point function to all orders in momenta and quark masses. The model is treated at leading level in $1/N_c$ but otherwise exact. ... More
Quantum Space-time and Classical GravityJul 24 1996A method has been recently proposed for defining an arbitrary number of differential calculi over a given noncommutative associative algebra. As an example a version of quantized space-time is considered here. It is found that there is a natural differential ... More
Spin diffusion of the t-J modelDec 12 1994Dec 13 1994The spin-diffusion constant of the 2D $t-J$ model is calculated for the first time using an analytical approach at high temperatures and a recently-developed numerical method based on the Lanczos technique combined with random sampling in the intermediate ... More
A term-rewriting system for computer quantum algebraSep 25 2008Existing computer algebra packages do not fully support quantum mechanics calculations in Dirac's notation. I present the foundation for building such support: a mathematical system for the symbolic manipulation of expressions used in the invariant formalism ... More
Transport properties of electrons and holes in a CuO2 layer doped by field effectMar 06 2002Apr 17 2002We propose a model for explaining the recent results obtained by J. Schon et al (1,2) on transport properties of electrons and holes in one plane of CuO2 in a layered cuprate (CaCuO2) where the carriers are created using a field effect transistor (FET). ... More
Hall effect in the normal state of high Tc cupratesOct 06 2003We propose a model for explaining the dependence in temperature of the Hall effect of high Tc cuprates in the normal state in various materials. They all show common features: a decrease of the Hall coefficient RH with temperature and a universal law, ... More
Computational Ergodicity of $s^4$Nov 07 1994It is known that there are four-manifolds which are not algorithmically recognizable. This implies that there exist triangulations of these manifolds which are separated by large barriers from the point of view of the computer algorithm. We have not observed ... More
On the exponential bound in four dimensional simplicial gravityMay 11 1994Simplicial quantum gravity has been proposed as a regularization for four dimensional quantum gravity. The partition function is constructed by performing a weighted sum over all triangulations of the 4-sphere. The model is well-defined only if the number ... More
Distance growth of quantum states due to initial system--environment correlationsMay 03 2010Intriguing features of the distance between two arbitrary states of an open quantum system are identified that are induced by initial system-environment correlations. As an example, we analyze a qubit dephasingly coupled to a bosonic environment. Within ... More
Impact of LISA's low frequency sensitivity on observations of massive black hole mergersNov 22 2004LISA will be able to detect gravitational waves from inspiralling massive black hole (MBH) binaries out to redshifts z > 10. If the binary masses and luminosity distances can be extracted from the LISA data stream, this information can be used to reveal ... More
Effective fermion kinematics from a modified quantum gravityJun 11 2015Sep 05 2016We consider a classical fermion and a classical scalar, propagating on two different kinds of 4-dimensional diffeomorphism breaking gravity backgrounds, and we derive the one-loop effective dispersion relation for matter, after integrating out gravitons. ... More
Negative Screenings in Conformal Field Theory and 2D Gravity: The Braiding MatrixApr 20 1999We consider an extension of the Coulomb gas picture which is motivated by Liouville theory and contains negative powers of screening operators on the same footing as positive ones. The braiding problem for chiral vertex operators in this extended framework ... More
High-Order Coupled Cluster Method (CCM) Formalism 2 -- "Generalised" Expectation Values: Spin-Spin Correlation Functions for Frustrated and Unfrustrated 2D AntiferromagnetsNov 27 2009Recent developments of high-order CCM have been to extend existing formalism and codes to $s \ge \frac 12$ for both the ground and excited states. In this article, we describe how "generalised" expectation values for a wide range of one- and two-body ... More
Jitter Self-Compton Process: GeV Emission of GRB 100728AMar 02 2012Jitter radiation, the emission of relativistic electrons in a random and small-scale magnetic field, has been applied to explain the gamma-ray burst (GRB) prompt emission. The seed photons produced from jitter radiation can be scattered by thermal/nonthermal ... More
Solution of the Skyrme-Hartree-Fock equations in the Cartesian deformed harmonic oscillator basis. (I) The methodNov 17 1996We describe a method of solving the nuclear Skyrme-Hartree-Fock problem by using a deformed Cartesian harmonic oscillator basis. The complete list of expressions required to calculate local densities, total energy, and self-consistent fields is presented, ... More
Spectral triples and aperiodic orderOct 01 2010Oct 22 2010We construct spectral triples for compact metric spaces (X, d). This provides us with a new metric d_s on X. We study its relation with the original metric d. When X is a subshift space, or a discrete tiling space, and d satisfies certain bounds we advocate ... More
Local minimizers and low energy paths in a model of material microstructure with a surface energy termSep 22 2008A family of integral functionals F which, in a simplified way, model material microstructure occupying a two-dimensional domain D and which take account of surface energy and a variable well-depth is studied. It is shown that there is a critical well-depth, ... More
On one-homogeneous solutions to elliptic systems with spatial variable dependence in two dimensionsSep 23 2008We extend the result of D. Phillips (On one-homogeneous solutions to elliptic systems in two dimensions. C. R. Math. Acad. Sci. Paris 335 (2002), no. 1, 39-42) by showing that one-homogeneous solutions of certain elliptic systems in divergence form either ... More
Symmetry and Stability of Homogenuous Flocks. A Position PaperOct 24 2018The study of the movement of flocks, whether biological or technological is motivated by the desire to understand the capability of coherent motion of a large number of agents that only receive very limited information. In a biological flock a large group ... More
Unified treatment of multisymplectic 3-forms in dimension 6May 06 2004On a 6-dimensional real vector space $V$ there are three types of multisymplectic 3-forms. We present in this paper a unified treatment of these three types. Forms of each type represent a subset of $\Lambda^3 V^*$. In two cases they are open subsets, ... More
Stability of spherical stellar systems I : Analytical resultsNov 22 1995The so-called ``symplectic method'' is used for studying the linear stability of a self-gravitating collisionless stellar system, in which the particles are also submitted to an external potential. The system is steady and spherically symmetric, and its ... More
Film transitions of receding contact linesJun 19 2007When a solid plate is withdrawn from a liquid bath, a receding contact line is formed where solid, liquid, and gas meet. Above a critical speed $U_{cr}$, a stationary contact line can no longer exist and the solid will eventually be covered completely ... More
Toy Stars in two dimensionsOct 25 2005Toy Stars are gas masses where the compressibility is treated without approximations but gravity is replaced by a force which, for any pair of masses, is along their line of centres and proportional to their separation. They provide an invaluable resource ... More
Smoothed Particle Magnetohydrodynamics II. Variational principles and variable smoothing length termsOct 28 2003In this paper we show how a Lagrangian variational principle can be used to derive the SPMHD (smoothed particle magnetohydrodynamics) equations for ideal MHD. We also consider the effect of a variable smoothing length in the SPH kernels after which we ... More
The neutrino charge radius is a physical observableOct 03 2002We present a method which allows, at least in principle, the direct extraction of the gauge-invariant and process-independent neutrino charge radius (NCR) from experiments. Under special kinematic conditions, the judicious combination of neutrino and ... More
Superfluid phases of $^3$He in a periodic confined geometryJul 27 2013Nov 17 2013Predictions and discoveries of new phases of superfluid $^3$He in confined geometries, as well as novel topological excitations confined to surfaces and edges of near a bounding surface of $^3$He, are driving the fields of superfluid $^3$He infused into ... More