Results for "P. P. Deen"

total 119933took 0.14s
Updating the phase diagram of the archetypal frustrated magnet Gd3Ga5O12Jan 14 2015The applied magnetic field and temperature phase diagram of the archetypal frustrated magnet, Gd3Ga5O12, has been reinvestigated using single crystal magnetometry and polarised neutron diffraction. The updated phase diagram is substantially more complicated ... More
Coexistence of the long-range and short-range magnetic order components in SrEr$_2$O$_4$Jun 03 2011Single crystal neutron diffraction reveals two distinct components to the magnetic ordering in geometrically frustrated SrEr$_2$O$_4$. One component is a long-range ordered ${\bf k}=0$ structure which appears below $T_N = 0.75$ K. Another component is ... More
A design study of VOR: a versatile optimal resolution chopper spectrometer for the ESSJul 02 2014VOR, the versatile optimal resolution chopper spectrometer, is designed to probe dynamic phenomena that are currently inaccessible for inelastic neutron scattering due to flux limitations. VOR is a short instrument by the standards of the European Spallation ... More
Dispersionless spin waves in Gadolinium Gallium GarnetJan 14 2015We report the results of neutron scattering on a powder sample of Gd3Ga5O12 at high magnetic fields. We find that in high fields (B>1.8 T) the system is not fully polarized, but has a small canting of the moments induced by the dipolar interaction. We ... More
Disentangling time-focusing from beam divergence: a novel approach for high-flux thermal neutron spectroscopy at continuous and long-pulse sourcesApr 12 2019We present the concept of a novel time-focusing technique for neutron spectrometers, which allows to disentangle time-focusing from beam divergence. The core of this approach is a double rotating-crystal monochromator that can be used to extract a larger ... More
Contact Changes of Sheared Systems: Scaling, Correlations, and MechanismsJun 15 2016We probe the onset and effect of contact changes in 2D soft harmonic particle packings which are sheared quasistatically under controlled strain. First, we show that in the majority of cases, the first contact changes correspond to the creation or breaking ... More
Spin dynamics in the frustrated three-dimensional hyperkagom{é} compound $Gd_3 Ga_5 O_{12}$Apr 23 2010We present the first neutron inelastic scattering results on the low temperature magnetic state of the three dimensional hyperkagom\'e compound Gd$_{3}$Ga$_{5}$O$_{12}$ (GGG). GGG is often classified as a strongly frustrated system with a manifold of ... More
Contact Changes near JammingApr 11 2014Aug 18 2014We probe the onset and effect of contact changes in soft harmonic particle packings which are sheared quasistatically. We find that the first contact changes are the creation or breaking of contacts on a single particle. We characterize the critical strain, ... More
Spin correlations and exchange in square lattice frustrated ferromagnetsSep 03 2009The J1-J2 model on a square lattice exhibits a rich variety of different forms of magnetic order that depend sensitively on the ratio of exchange constants J2/J1. We use bulk magnetometry and polarized neutron scattering to determine J1 and J2 unambiguously ... More
On the Ordering of Na$^+$ Ions in Na$_x$CoO$_2$Oct 18 2005The influence of electrostatic interactions on the ordering of sodium ions in Na$_x$CoO$_2$ is studied theoretically through Monte-Carlo simulations. For large $x$ small di- or tri-vacancy clusters are stable with respect to isolated Na vacancies. At ... More
Pair Correlations, Short Range Order and Dispersive Excitations in the Quasi-Kagome Quantum Magnet VolborthiteJan 14 2010Feb 27 2011We present spatial and dynamic information on the s=1/2 distorted kagome antiferromagnet volborthite, Cu3V2O7(OD)2.2D2O, obtained by polarized and inelastic neutron scattering. The instantaneous structure factor, S(Q), is dominated by nearest neighbor ... More
Scale-free antiferromagnetic fluctuations in the S=1/2 kagome antiferromagnet herbertsmithiteFeb 18 2009Dec 21 2009Neutron spectroscopy and diffuse neutron scattering on herbertsmithite [ZnCu3 (OH)6Cl2], a near-ideal realisation of the s = 1/2 kagome antiferromagnet, reveal the hallmark property of a quantum spin liquid; instantaneous short-ranged antiferromagnetic ... More
Experimental Proof of a Magnetic Coulomb PhaseJul 06 2009Spin ice materials are magnetic substances in which the spin directions map onto hydrogen positions in water ice. Recently this analogy has been elevated to an electromagnetic equivalence, indicating that the spin ice state is a Coulomb phase, with magnetic ... More
Spin correlations in Ca3Co2O6: A polarised-neutron diffraction and Monte Carlo studyDec 18 2013We present polarised-neutron diffraction measurements of the Ising-like spin-chain compound Ca3Co2O6 above and below the magnetic ordering temperature TN. Below TN, a clear evolution from a single-phase spin-density wave (SDW) structure to a mixture of ... More
Characterizing TW HydraDec 13 2017At 60 pc, TW Hydra (TW Hya) is the closest example of a star with a gas-rich protoplanetary disk, though TW Hya may be relatively old (3-15 Myr). As such, TW Hya is especially appealing to test our understanding of the interplay between stellar and disk ... More
Polarization-mediated Debye-screening of surface potential fluctuations in dual-channel AlN/GaN high electron mobility transistorsOct 13 2016A dual-channel AlN/GaN/AlN/GaN high electron mobility transistor (HEMT) architecture is proposed, simulated, and demonstrated that suppresses gate lag due to surface-originated trapped charge. Dual two-dimensional electron gas (2DEG) channels are utilized ... More
Patterning of sodium ions and the control of electrons in sodium cobaltateJul 01 2005Apr 13 2007NaxCoO2 has emerged as a material of exceptional scientific interest due to the potential for thermoelectric applications, and because the strong interplay between the magnetic and superconducting properties has led to close comparisons with the physics ... More
Long-range magnetic order in CeRu2Al10 evidenced by muSR and neutron diffractionJun 08 2010The low temperature state of CeRu2Al10 has been studied by neutron powder diffraction and muon spin relaxation (muSR). By combining both techniques, we prove that the transition occurring below T*~27K, which has been the subject of considerable debate, ... More
Modification of the MOOG spectral synthesis codes to account for Zeeman broadening of spectral linesJun 27 2013In an attempt to widen access to the study of magnetic fields in stellar astronomy, I present MOOGStokes, a version of the MOOG one-dimensional LTE radiative transfer code, overhauled to incorporate a Stokes vector treatment of polarized radiation through ... More
Competing 4f-electron dynamics in Ce(Ru1-xFex)2Al10 (x=0 to 1): magnetic ordering emerging from the Kondo semiconducting stateJun 02 2013We have carried out muon spin relaxation (muSR), neutron diffraction and inelastic neutron scattering (INS) investigations on polycrystalline samples of Ce(Ru1-xFex)2Al10 (x=0, 0.3, 0.5, 0.8 and 1) to investigate the nature of the ground state (magnetic ... More
Momentum-space structure of quasielastic spin fluctuations in Ce3Pd20Si6Oct 01 2014Among heavy-fermion metals, Ce$_3$Pd$_{20}$Si$_6$ is one of the heaviest-electron systems known to date. Here we used high-resolution neutron spectroscopy to observe low-energy magnetic scattering from a single crystal of this compound in the paramagnetic ... More
New structural and magnetic aspects of the nanotube system Na2V3O7Sep 07 2008We present new experimental results of low temperature x-ray synchrotron diffraction, neutron scattering and very low temperature (mK-range) bulk measurements on the nanotube system ${\tube}$. The crystal structure determined from our data is similar ... More
Physical parameters and $\pm$0.2% parallax of the detached eclipsing binary V923 ScorpiiApr 26 2018V923 Sco is a bright ($V$ = 5.91), nearby ($\pi$ = 15.46$\pm$0.40 mas) southern eclipsing binary. Because both components are slow rotators, the minimum masses of the components are known with 0.2% precision from spectroscopy. The system seems ideal for ... More
Direct evidence of long-range ordering of reduced magnetic moments in the spin-gap compound CeOs2Al10 through muon spin relaxation investigationsAug 20 2010We have carried out neutron diffraction, muon spin relaxation (muSR) and inelastic neutron scattering investigations on a polycrystalline sample of CeOs2Al10 to investigate the nature of the phase transition observed near 29 K in the resistivity and heat ... More
Antiferromagnetic Order in MnO Spherical NanoparticlesJun 15 2011We have performed unpolarized and polarized neutron diffraction experiments on monodisperse 8 nm and 13 nm antiferromagnetic MnO nanoparticles. For the 8 nm sample, the antiferromagnetic transition temperature $T_N$ (114 K) is suppressed compared to the ... More
Pinning-induced pn junction formation in low-bandgap two-dimensional semiconducting systemsSep 01 2015A model is presented for $pn$ junction formation near metal-semiconductor contacts in two-dimensional semiconducting systems such as graphene. Carrier type switching occurs in a region near the metal-semiconductor junction when energy band bending leads ... More
Multi-Grid Detector for Neutron Spectroscopy: Results Obtained on Time-of-Flight Spectrometer CNCSMar 10 2017Apr 03 2017The Multi-Grid detector technology has evolved from the proof-of-principle and characterisation stages. Here we report on the performance of the Multi-Grid detector, the MG.CNCS prototype, which has been installed and tested at the Cold Neutron Chopper ... More
Magnetic ground state and magnon-phonon interaction in multiferroic h-YMnO$_3$Jul 08 2017Apr 18 2018Inelastic neutron scattering has been used to study the magneto-elastic excitations in the multiferroic manganite hexagonal YMnO$_3$. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the $(a,b)$-plane. ... More
Visualizing Object-oriented Software for Understanding and DocumentationJan 28 2016Understanding or comprehending source code is one of the core activities of software engineering. Understanding object-oriented source code is essential and required when a programmer maintains, migrates, reuses, documents or enhances source code. The ... More
Automatic Labeling of the Object-oriented Source Code: The Lotus ApproachJan 25 2018Most of open-source software systems become available on the internet today. Thus, we need automatic methods to label software code. Software code can be labeled with a set of keywords. These keywords in this paper referred as software labels. The goal ... More
High Dimensional Model Representation as a Glass Box in Supervised Machine LearningJul 26 2018Prediction and explanation are key objects in supervised machine learning, where predictive models are known as black boxes and explanatory models are known as glass boxes. Explanation provides the necessary and sufficient information to interpret the ... More
The Minimal SUSY $B-L$ Model: Simultaneous Wilson Lines and String ThresholdsApr 28 2016May 20 2016In previous work, we presented a statistical scan over the soft supersymmetry breaking parameters of the minimal SUSY $B-L$ model. For specificity of calculation, unification of the gauge parameters was enforced by allowing the two ${\mathbb Z}_{3}\times ... More
Color and Shape Content Based Image Classification using RBF Network and PSO Technique: A SurveyNov 27 2013The improvement of the accuracy of image query retrieval used image classification technique. Image classification is well known technique of supervised learning. The improved method of image classification increases the working efficiency of image query ... More
Throwing Stones and Collecting Bones: Looking for Poisson-like Random MeasuresJul 25 2018We show that in a broad class of probabilistic random measures one may identify only three that are rescaled versions of themselves when restricted to a subspace. These are Poisson, binomial and negative binomial random measures. We provide some simple ... More
Supersymmetric Sneutrino-Higgs InflationJun 01 2016It is shown that in the phenomenologically realistic supersymmetric $B-L$ MSSM theory, a linear combination of the neutral, up Higgs field with the third family left-and right-handed sneutrinos can play the role of the cosmological inflaton. Assuming ... More
Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA*Oct 30 2018We report the detection of continuous positional and polarization changes of the compact source SgrA* in high states ('flares') of its variable near- infrared emission with the near-infrared GRAVITY-Very Large Telescope Interferometer (VLTI) beam-combining ... More
Accretion-ejection morphology of the microquasar SS433 resolved at sub-au scaleMay 05 2017We present the first optical observation at sub-milliarcsecond (mas) scale of the microquasar SS 433 obtained with the GRAVITY instrument on the VLT interferometer. The 3.5 hour exposure reveals a rich K-band spectrum dominated by hydrogen Br$\gamma\ ... More
Sub-milliarcsecond Optical Interferometry of the HMXB BP Cru with VLTI/GRAVITYMay 05 2017We observe the HMXB BP Cru using interferometry in the near-infrared K band with VLTI/GRAVITY. Continuum visibilities are at most partially resolved, consistent with the predicted size of the hypergiant. Differential visibility amplitude ($\Delta |V| ... More
Electrical Conductance in Biological MoleculesMar 21 2010May 09 2010Nucleic acids and proteins are not only biologically important polymers: They have recently been recognized as novel functional materials surpassing in many aspects the conventional ones. Although Herculean efforts have been undertaken to unravel fine ... More
The Algorithm Analysis of E-Commerce Security Issues for Online Payment Transaction System in Banking TechnologyMay 24 2010E-Commerce offers the banking industry great opportunity, but also creates a set of new risks and vulnerability such as security threats. Information security, therefore, is an essential management and technical requirement for any efficient and effective ... More
The Impact of the Object-Oriented Software Evolution on Software Metrics: The Iris ApproachMar 15 2018The Object-Oriented (OO) software system evolves over the time to meet the new requirements. Based on the initial release of software, the continuous modification of software code leads to software evolution. Software needs to evolve over the time to ... More
Charge multiplets and masses for E(11)May 28 2008Oct 30 2008The particle, string and membrane charge multiplets are derived in detail from the decomposition of the l1 (charge) representation of E(11) in three, four, five, six, seven and eight spacetime dimensions. A tension formula relating weights of the l1 (charge) ... More
Supporting software documentation with source code summarizationDec 14 2018Source code summarization is a process of generating summaries that describe software code, the majority of source code summarization usually generated manually, where the summaries are written by software developers. Recently, new automated approaches ... More
Perturbative Reheating in Sneutrino-Higgs CosmologyApr 20 2018Sep 26 2018The theory of perturbative reheating in the Sneutrino-Higgs cosmology of the $B-L$ MSSM is presented. It is shown that following an epoch of inflation consistent with all Planck2015 data, the inflaton begins to oscillate around its minimum at zero and ... More
First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 eMar 28 2019To date, infrared interferometry at best achieved contrast ratios of a few times $10^{-4}$ on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast observations, enabling the direct observation of exoplanets. We demonstrate ... More
Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black holeJul 25 2018The highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A* is a sensitive probe of the gravitational field in the Galactic centre. Near pericentre at 120 AU, ~1400 Schwarzschild radii, the star has an orbital ... More
The coincidence problem in linear dark energy modelsNov 01 2004Nov 12 2004We show that a solution to the the coincidence problem can be found in the context of a generic class of dark energy models with a scalar field, $\phi$, with a linear effective potential $V(\phi)$. We determine the fraction, $f$, of the total lifetime ... More
Could the dynamics of the Universe be influenced by what is going on inside black holes?Nov 01 2014Mar 26 2015We investigate the potential impact of mass inflation inside black holes on the dynamics of the Universe, considering a recent reformulation of general relativity, proposed in [1], which prevents the vacuum energy from acting as a gravitational source. ... More
Impact of the matter density uncertainty on the dark energy reconstructionMar 04 2009Jun 24 2009In this paper we study the impact of the fractional matter density uncertainty in the reconstruction of the equation of state of dark energy. We consider both standard reconstruction methods, based on the dynamical effect that dark energy has on the expansion ... More
Mass inflation in Eddington-inspired Born-Infeld black holes: analytical scaling solutionsFeb 26 2016We study the inner dynamics of accreting Eddington-inspired Born-Infeld black holes using the homogeneous approximation and taking charge as a surrogate for angular momentum. We show that there is a minimum of the accretion rate below which mass inflation ... More
Nonlocal conservation laws in N=1,2 Supersymetric KdV equationJan 19 1993The \nl \cls for the N=1 supersymmetric KdV equation are shown to be related in a simple way to powers of the fourth root of its Lax operator. This provides a direct link between the supersymmetry invariance and the existence of \nl conservation laws. ... More
Sensitivity of the Superconducting Transition Temperature to Changes in the Spin-Fluctuation Spectral WeightNov 20 2002In the simplest model of magnetic pairing, the transition temperature to the superconducting state depends on the dynamical susceptibility $\chi({\bf q},\omega)$. We discuss how $T_c$ is affected by different momentum and frequency parts of $\chi({\bf ... More
Description of Stellar Acoustic Modes Using the Local Wave ConceptJun 26 2006An understanding of stellar acoustic oscillations is attempted, using the local wave concept in semi-analytical calculations. The local homogeneity approximation allows to obtain simplified equations that can nevertheless describe the wave behavior down ... More
ad-nilpotent ideals of a Borel subalgebra IIIMar 05 2003Sep 30 2003This paper is devoted to a detailed study of certain remarkable posets which form a natural partition of all abelian ideals of a Borel subalgebra. Our main result is a nice uniform formula for the dimension of maximal ideals in these posets. We also obtain ... More
Resonance statistics in a microwave cavity with a thin antennaFeb 07 1997We propose a model for scattering in a flat resonator with a thin antenna. The results are applied to rectangular microwave cavities. We compute the resonance spacing distribution and show that it agrees well with experimental data provided the antenna ... More
An analysis of the zero energy states in grapheneDec 09 2015Using the concept of complex non PT symmetric potential we study creation of zero energy states in graphene by a scalar potential. The admissible range of the potential parameter values for which such states exist has been examined. The situation with ... More
Gribov Copies in Lattice QCDJun 15 1993We have performed an exhaustive search for Gribov copies on the lattice and their possible dependence from finite temperature effects. We show that, for each value of lattice size, Gribov copies are dense in configuration space at low temperature but ... More
Particles in RSOS pathsJan 13 2009Mar 03 2009We introduce a new representation of the paths of the Forrester-Baxter RSOS models which represents the states of the irreducible modules of the minimal models M(p',p). This representation is obtained by transforming the RSOS paths, for the cases p> 2p'-2, ... More
Fermi-gas interpretation of the RSOS path representation of the superconformal unitary minimal modelsMay 15 2008Aug 12 2008We derive new finitized fermionic characters for the superconformal unitary minimal models by interpreting the RSOS configuration sums as fermi-gas partition functions. This extends to the supersymmetric case the method introduced by Warnaar for the Virasoro ... More
Graded parafermions: standard and quasi-particle basesJan 20 2002Feb 05 2002Two bases of states are presented for modules of the graded parafermionic conformal field theory associated to the coset $\osp(1,2)_k/\uh(1)$. The first one is formulated in terms of the two fundamental (i.e., lowest dimensional) parafermionic modes. ... More
ROSAT Observations of Compact Groups of GalaxiesDec 11 1994Dec 15 1994A search for X-ray emission from compact groups revealed detection from 8 out of the 12 HCG images extracted from the ROSAT public archive. For two of them the X-ray emission originates from galaxies in the group. On the contrary, three groups show an ... More
A faithful tensor space representation for the blob algebraDec 19 2003We show that a certain tensor space representation of the blob algebra (an affine Hecke algebra quotient) is faithful.
Vacuum energy sequestering and cosmic dynamicsOct 16 2014We explicitly compute the dynamics of closed homogeneous and isotropic universes permeated by a single perfect fluid with a constant equation of state parameter $w$ in the context of a recent reformulation of general relativity, proposed in [1], which ... More
On the cosmological evolution of alpha and mu and the dynamics of dark energyApr 22 2008We study the cosmological evolution of the fine structure constant, $\alpha$, and the proton-to-electron mass ratio, $\mu=m_p/m_e$, in the context of a generic class of models where the gauge kinetic function is a linear function of a quintessence-type ... More
Interacting dark energy: the role of microscopic feedback in the dark sectorFeb 09 2015Mar 10 2015We investigate the impact on the classical dynamics of dark matter particles and dark energy of a non-minimal coupling in the dark sector, assuming that the mass of the dark matter particles is coupled to a dark energy scalar field. We show that standard ... More
In medium T matrix for neutron matterApr 03 2002Jun 18 2002We calculate the equation of state of pure neutron matter, comparing the G-matrix calculation with the in-medium T-matrix result. At low densities, we obtain similar energies per nucleon, however some differences appear at higher densities. We use the ... More
Energy dependence of transverse quark flow in heavy ion collisionsJul 19 2004Energy dependence of quark transverse flow carries information about dynamical properties (equation of state, initial conditions) of deconfined matter produced in heavy ion collisions. We assume quark-antiquark matter formation in Pb+Pb collisions at ... More
D and J/psi production from deconfined matter in relativistic heavy ion collisionsAug 18 2000We study the production of the D and J/psi mesons from deconfined quark matter at CERN SPS energy. Using the MICOR microscopical coalescence model we determine the transverse momentum spectra of these charm mesons. We predict the slopes of their transverse ... More
Molecular Dipolar Crystals as High Fidelity Quantum Memory for Hybrid Quantum ComputingJun 20 2007We study collective excitations of rotational and spin states of an ensemble of polar molecules, which are prepared in a dipolar crystalline phase, as a candidate for a high fidelity quantum memory. While dipolar crystals are formed in the high density ... More
Impact of nuclear effects on the extraction of neutrino oscillation parametersJul 04 2013Dec 03 2013We study the possible impact of nuclear effects and final state interactions on the determination of the oscillation parameters due to mis-reconstruction of non-quasi-elastic events as quasi-elastic events at low energies. We analyze a $\nu_\mu$ disappearance ... More
Interlayer Exchange Coupling in (Ga,Mn)As-based SuperlatticesFeb 14 2005The interlayer coupling between (Ga,Mn)As ferromagnetic layers in all-semiconductor superlattices is studied theoretically within a tight-binding model, which takes into account the crystal, band and magnetic structure of the constituent superlattice ... More
Non-Perturbative Superpotentials in F-theory and String DualityApr 07 2005May 12 2005We use open-closed string duality between F-theory on K3xK3 and type II strings on CY manifolds without branes to study non-perturbative superpotentials in generalized flux compactifications. On the F-theory side we obtain the full flux potential including ... More
Successive Injection of Opposite Magnetic Helicity in Solar Active Region NOAA 11928Nov 02 2016Understanding the nature and evolution of the photospheric helicity flux transfer is a key to reveal the role of magnetic helicity in coronal dynamics of solar active regions. Using SDO/HMI photospheric vector magnetograms and the derived flow velocity ... More
Multiple partitions, lattice paths and a Burge-Bressoud-type correspondenceAug 31 2006Jan 15 2008A bijection is presented between (1): partitions with conditions $f_j+f_{j+1}\leq k-1$ and $ f_1\leq i-1$, where $f_j$ is the frequency of the part $j$ in the partition, and (2): sets of $k-1$ ordered partitions $(n^{(1)}, n^{(2)}, ..., n^{(k-1)})$ such ... More
Single- and Two-Component GRB Spectra in the Fermi GBM-LAT Energy RangeFeb 13 2012Jun 04 2012Most Fermi GRB spectra appear as either a broken power law extending to GeV energies or as a broken power with a separate GeV power law component. Here we show that such spectra can be understood in terms of magnetically dominated relativistic jets where ... More
The limiting behavior of the Liu-Yau quasi-local energyJun 07 2007The small- and large-sphere limits of the quasi-local energy recently proposed by Liu and Yau are carefully examined. It is shown that in the small-sphere limit, the non-vacuum limit of the Liu-Yau quasi-local energy approaches the expected value \frac{4\pi}{3} ... More
Constraining the physics of the early UniverseMar 26 2019The established cosmological theory which describes the history of the Universe since shortly after the "Big Bang" until today is remarkably successful. Thanks to the increasing precision of available observational data, we are now able to considerably ... More
Eddington-inspired Born-Infeld gravity: astrophysical and cosmological constraintsJan 12 2012In this letter we compute stringent astrophysical and cosmological constraints on a recently proposed Eddington-inspired Born-Infeld theory of gravity. We find, using a generalized version of the Zel'dovich approximation, that in this theory a pressureless ... More
Unified approach to growth and aging in biological, technical and biotechnical systemsJul 16 2012Complex systems, in many different scientific sectors, show coarse-grain properties with simple growth laws with respect to fundamental microscopic algorithms. We propose a classification scheme of growth laws which includes human aging, tumor (and/or ... More
Lorentz-Invariant Interpretation of Noncommutative Space-Time - global versionAug 12 2004Aug 24 2004The global version of the quantum symmetry defined by Chaichian et al (hep-th/0408069) is constructed.
Stability of vector bundles from F-theoryApr 15 1999We use a recently proposed formulation of stable holomorphic vector bundles $V$ on elliptically fibered Calabi--Yau n-fold $Z_n$ in terms of toric geometry to describe stability conditions on $V$. Using the toric map $f: W_{n+1} \to (V,Z_n)$ that identifies ... More
On the geometry of the characteristic class of a star product on a symplectic manifoldDec 28 2001The characteristic class of a star product on a symplectic manifold appears as the class of a deformation of a given symplectic connection, as described by Fedosov. In contrast, one usually thinks of the characteristic class of a star product as the class ... More
Nonlocal operator basis from the path representation of the M(k+1,k+2) and the M(k+1,2k+3) minimal modelsFeb 28 2008Aug 12 2008We reinterpret a path describing a state in an irreducible module of the unitary minimal model M(k+1,k+2) in terms of a string of charged operators acting on the module's ground-state path. Each such operator acts non-locally on a path. The path characteristics ... More
Paths for Z_k parafermionic modelsMar 01 2007Jul 03 2007We present a simple bijection between restricted (Bressoud) lattice paths and RSOS paths in regime II. Both types of paths describe states in Z_k parafermionic irreducible modules. The bijection implies a direct correspondence between a RSOS path and ... More
Embedding of bases: from the M(2,2k+1) to the M(3,4k+2-delta) modelsNov 03 2005Nov 09 2005A new quasi-particle basis of states is presented for all the irreducible modules of the M(3,p) models. It is formulated in terms of a combination of Virasoro modes and the modes of the field phi_{2,1}. This leads to a fermionic expression for particular ... More
Single-channel correlators and residue calculusMay 31 2001Aug 04 2001Some simple (namely, single-channel) correlation functions involving an arbitrary number of fields are computed by means of a direct application of the residue calculus, through partial fraction expansions. Examples are presented in minimal models and ... More
Prospects for GeV-TeV detection of short gamma-ray bursts with extended emissionDec 02 2013Apr 21 2014We discuss the GeV to TeV photon emission of gamma-ray bursts (GRBs) within the refreshed shock and the continuous injection scenarios, motivated by the observation of extended emission in a substantial fraction of short GRBs. In the first model we assume ... More
H_αLuminosity and Star Formation of Galaxies in HCGsApr 07 1999We have obtained $H_{\alpha}$ fluxes and luminosities for a sample of 95 accordant galaxies from observations of 31 Hickson Compact Groups (HCGs) in the North hemisphere. This sample is the largest $H_{\alpha}$ selected catalogue of galaxies having $H_{\alpha}$ ... More
The study on penetration depth of anisotropic two-band s-wave superconductors by Ginzburg-Landau approachMar 29 2019The penetration depth of anisotropic two-band s-wave superconductors have been studied by Ginzburg-Landau approach. The anisotropic spherical Fermi surfaces and order parameters with the spherical ellipse or pancake Fermi shape are used for derive penetration ... More
Investigating a Fluctuating-accretion Model for the Spectral-timing Properties of Accreting Black Hole SystemsDec 15 2005The fluctuating accretion model of Lyubarskii (1997) and its extension by Kotov et al. (2001), seeks to explain the spectral-timing properties of the X-ray variability of accreting black holes in terms of inward-propagating mass accretion fluctuations ... More
Point interaction in dimension two and three as models of small scatterersJul 03 1996In addition to the conventional renormalized--coupling--constant picture, point interactions in dimension two and three are shown to model within a suitable energy range scattering on localized potentials, both attractive and repulsive.
Enhancement of Tc by Sr substitution for Ba in Hg-2212 superconductorApr 16 2003Sep 23 2003The Ba substitution by Sr has been studied in two Hg-2212 series: Hg2(Ba(1-y)Sr(y))2YCu2O8-d and Hg2(Ba(1-y)Sr(y))2(Y0.80Ca0.20)Cu2O8-d. In both series a Tc enhancement of about 40 K is observed when Sr substitutes Ba from y = 0 to y = 1.0. The y = 0 ... More
Characteristic Relations for Quantum MatricesFeb 20 1995Feb 24 1995General algebraic properties of the algebras of vector fields over quantum linear groups $GL_q(N)$ and $SL_q(N)$ are studied. These quantum algebras appears to be quite similar to the classical matrix algebra. In particular, quantum analogues of the characteristic ... More
A new approach to the connection problem for local solutions to the general Heun equationJun 28 2016Jul 03 2016We present new solution of the the connection problem for local solutions to the general Heun equation. Our approach is based on the symmetric form of the Heun's differential equation \cite{Fiziev14,Fiziev16} with four different regular singular points ... More
Inner Structure of Black Holes in Eddington-inspired Born-Infeld gravity: the role of mass inflationNov 10 2015We investigate the interior dynamics of accreting black holes in Eddington-inspired Born-Infeld gravity using the homogeneous approximation and taking charge as a surrogate for angular momentum, showing that accretion can have an enormous impact on their ... More
Primordial black hole constraints on non-gaussian inflation modelsOct 03 2005We determine the abundance of primordial black holes (PBHs) formed in the context of non-gaussian models with primordial density perturbations. We consider models with a renormalized $\chi^2$ probability distribution function parametrized by the number, ... More
Eddington-inspired Born-Infeld gravity: nuclear physics constraints and the validity of the continuous fluid approximationJul 19 2012In this paper we investigate the classical non-relativistic limit of the Eddington-inspired Born-Infeld theory of gravity. We show that strong bounds on the value of the only additional parameter of the theory \kappa, with respect to general relativity, ... More
Efficiency of the coherent biexciton admixture mechanism for multiple exciton generation in InAs nanocrystalsJun 23 2015We study the coherent mixing between two-particle (single exciton) and four-particle (biexciton) states of a semiconductor nanocrystal resulting from the coulomb coupling between states with different numbers of electron-hole pairs. Using a simple model ... More
Thermodynamic consistency for nuclear matter calculationsFeb 10 2001We investigate the relation between the binding energy and the Fermi energy and between different expressions for the pressure in cold nuclear matter. For a self-consistent calculation based on a $\Phi$ derivable $T-$matrix approximation with off-shell ... More
Laser probing of atomic Cooper pairsJan 24 2000We consider a gas of attractively interacting cold Fermionic atoms which are manipulated by laser light. The laser induces a transition from an internal state with large negative scattering length to one with almost no interactions. The process can be ... More