Results for "J. Balibrea"

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A Theoretical Framework for Lagrangian DescriptorsMay 29 2017This paper provides a theoretical background for Lagrangian Descriptors (LDs). The goal of achieving rigourous proofs that justify the ability of LDs to detect invariant manifolds is simplified by introducing an alternative definition for LDs. The definition ... More
Response to: "Limitations of the Method of Lagrangian Descriptors" [arXiv:1510.04838]Jan 30 2016This Response is concerned with the recent Comment of Ruiz-Herrera, "Limitations of the Method of Lagrangian Descriptors" [arXiv:1510.04838], criticising the method of Lagrangian Descriptors. In spite of the significant body of literature asserting the ... More
On forbidden setsMay 26 2015In recent literature there are an increasing number of papers where the forbidden sets of difference equations are computed. We review and complete different attempts to describe the forbidden set and propose new perspectives for further research and ... More
Newton maps for quintic polynomialsJan 20 2005The purpose of this paper is to study some properties of the Newton maps associated to real quintic polynomials. First using the Tschirnhaus transformation, we reduce the study of Newton's method for general quintic polynomials to the case $f(x)=x^{5}-c ... More
Chaotic Dynamics in Nonautonomous Maps: Application to the Nonautomous Henon MapMay 29 2017In this paper we analyze chaotic dynamics for two dimensional nonautonomous maps through the use of a nonautonomous version of the Conley-Moser conditions given previously. With this approach we are able to give a precise definition of what is meant by ... More
Lagrangian Descriptors for Two Dimensional, Area Preserving, Autonomous and Nonautonomous MapsMay 31 2017In this paper we generalize the method of Lagrangian descriptors to two dimensional, area preserving, autonomous and nonautonomous discrete time dynamical systems. We consider four generic model problems--a hyperbolic saddle point for a linear, area-preserving ... More
Topological equivalences for one-parameter bifurcations of mapsMar 12 2015Nov 14 2016Homeomorphisms allowing us to prove topological equivalences between one-parameter families of maps undergoing the same bifurcation are constructed in this paper. This provides a solution for a classical problem in bifurcation theory that was set out ... More
The Chaotic Saddle in the Lozi map, autonomous and non-autonomous versionsMay 31 2017In this paper we prove the existence of a chaotic saddle for a piecewise linear map of the plane, referred to as the Lozi map. We study the Lozi map in its orientation and area preserving version. First, we consider the autonomous version of the Lozi ... More
Topological equivalences for one-parameter bifurcations of mapsMar 12 2015Homeomorphisms allowing us to prove topological equivalences between one-parameter families of maps undergoing the same bifurcation are constructed in this paper. This provides a solution for a classical problem in bifurcation theory that was set out ... More
Lagrangian Descriptors for Stochastic Differential Equations: A Tool for Revealing the Phase Portrait of Stochastic Dynamical SystemsMay 31 2017In this paper we introduce a new technique for depicting the phase portrait of stochastic differential equations. Following previous work for deterministic systems, we represent the phase space by means of a generalization of the method of Lagrangian ... More
Study of multi-neutron emission in the $β$-decay of $^{11}$LiJun 11 2019The kinematics of two-neutron emission following the $\beta$-decay of $^{11}$Li was investigated for the first time by detecting the two neutrons in coincidence and by measuring their angle and energy. An array of liquid-scintillator neutron detectors ... More
Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOFAug 03 2017Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows ... More
Experimental setup and procedure for the measurement of the 7Be(n,α)α reaction at n_TOFApr 01 2016The newly built second experimental area EAR2 of the n_TOF spallation neutron source at CERN allows to perform (n, charged particles) experiments on short-lived highly radioactive targets. This paper describes a detection apparatus and the experimental ... More
Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOFFeb 27 2019The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron ... More
Cross section measurements of $^{155,157}$Gd(n,$γ$) induced by thermal and epithermal neutronsMay 10 2018Neutron capture measurements on $^{155}$Gd and $^{157}$Gd were performed using the time-of-flight technique at the n\_TOF facility at CERN. Four samples in form of self-sustaining metallic discs isotopically enriched in $^{155}$Gd and $^{157}$Gd were ... More
Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOFFeb 27 2019Mar 04 2019The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron ... More
Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERNDec 04 2014Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the $^{243}$Am(n,$\gamma$) cross section uncertainty. Method: The $^{243}$Am(n,$\gamma$) ... More
The $^{7}$Be($\boldsymbol{n,p}$)$^{7}$Li reaction and the Cosmological Lithium Problem: measurement of the cross section in a wide energy range at n\_TOF (CERN)Jun 08 2018We report on the measurement of the $^{7}$Be($n, p$)$^{7}$Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n\_TOF facility at CERN. This reaction plays a key role in the ... More
The $^{7}$Be(n,p)$^{7}$Li reaction and the Cosmological Lithium Problem: measurement of the cross section in a wide energy range at n_TOF (CERN)Mar 15 2018We report on the measurement of the $^{7}$Be($n, p$)$^{7}$Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium ... 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
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
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
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
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
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.
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
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
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
Advanced quantum methods for the largest magnetic moleculesDec 03 2012We discuss modern numerical methods for quantum spin systems and their application to magnetic molecules.
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
Timing by Stellar Pulsations as an Exoplanet Discovery MethodAug 02 2017The stable oscillations of pulsating stars can serve as accurate timepieces, which may be monitored for the influence of exoplanets. An external companion gravitationally tugs the host star, causing periodic changes in pulsation arrival times. This method ... 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
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
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.
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
Polarisation of high-energy emission in a pulsar striped windJan 09 2007Recent observations of the polarisation of the optical pulses from the Crab pulsar motivated detailed comparative studies of the emission predicted by the polar cap, the outer gap and the two-pole caustics models. In this work, we study the polarisation ... 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
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
Navigating Around Convex SetsJun 17 2019We review some basic results of convex analysis and geometry in $\mathbb{R}^n$ in the context of formulating a differential equation to track the distance between an observer flying outside a convex set $K$ and $K$ itself.
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
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
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
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
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
The Cosmological Signatures and Flux Distribution of Gamma-Ray Bursts with a Broad Luminosity DistributionJul 10 1997Aug 16 1997The cosmological expansion cannot produce the reported correlations of the gamma-ray burst timescale and spectral energy with peak flux if the burst model reproduces the BATSE 3B peak-flux distribution for a non-evolving burst source density. Power law ... More
A Quantum Monte Carlo Study of Static Properties of One 3He Atom in Superfluid 4HeJul 20 1998The local environment and the energetic properties of one $^3$He atom solved in bulk superfluid $^4$He are studied by means of the diffusion Monte Carlo method. The chemical potential of the $^3$He impurity is calculated with a generalized reweighting ... More
Nuclear Suppression of Dileptons at Large xFSep 23 2009Oct 09 2009We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, ... More
A New Method for Finding Clusters of Galaxies at z>1Aug 16 1994At large redshifts, a cluster or group may be too distant for the galaxies within the cluster to be detected individually. However, the light from these ``undetected'' galaxies still modulates the surface brightness of the background sky. Clusters can ... More
Hadronization of Expanding QGPNov 04 2005We discuss how the dynamics of an exploding hot fireball of quark--gluon matter impacts the actual phase transition conditions between the deconfined and confined state of matter. We survey the chemical conditions prevailing at hadronization.
QCD Equations of State and the QGP Liquid ModelJan 15 2003Recent advances in the study of equations of state of thermal lattice Quantum Chromodynamics obtained at non-zero baryon density allow validation of the quark-gluon plasma (QGP) liquid model equations of state (EoS). We study here the properties of the ... More
Lensless Slide Projection: A Demonstrative ExperienceJun 27 2006A 2D transparency may be projected on a diffractive screen by just illuminating it with a filament lamp of the same height. Sharpness of the filament width is naturally related to sharpness on the image, but some peculiar properties makes this experience ... More
Holoprojection of Images by a Double Diffraction ProcessAug 17 2005Three dimensional images having continuous horizontal parallax were developed by wavelength enconding of view followed by a natural decoding process of projection onto a diffractive screen. It allows for the direct criation of "holoimages" by using projected ... More
Effective bounds for Faltings's delta functionDec 09 2013We obtain bounds for the Faltings's delta function for any Riemann surface of genus greater than one. The bounds are in terms of the genus of the surface and two basic quantities coming from hyperbolic geometry: The length of the shortest closed geodesic, ... More
Parametric resonance in quantum field theoryAug 07 2002Jul 09 2003We present the first study of parametric resonance in quantum field theory from a complete next-to-leading order calculation in a 1/N-expansion of the 2PI effective action, which includes scattering and memory effects. We present a complete numerical ... More
Transport Simulations with Pi and Delta In-Medium PropertiesJul 23 1998Transport simulations including in-medium properties derived in a microscopic pi + nucleon-hole + delta-hole model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial delta decay widths, pion absorption cross sections ... More
Treatment of Pionic Modes at the Nuclear Surface for Transport DescriptionsAug 22 1995Dispersion relations and amplitudes of collective pionic modes are derived in a pi + nucleon-hole + delta-hole model for use in transport descriptions by means of a local density approximation. It is discussed how pionic modes can be converted to real ... More
The Spectrum of the MSSM with Non-Standard Supersymmetry BreakingAug 24 2001Aug 29 2001The Minimal Supersymmetric Standard Model (MSSM) can include two soft breaking terms which are often neglected: a non-analytic scalar trilinear coupling and a Higgsino bilinear term. A set of high-scale boundary conditions consistent with the reparameterisation ... More
Tables of the partition functions for iron, Fe I -- Fe XApr 23 2002We present extensive tables of the Atomic Partition Function for iron ions, Fe I -- Fe X, and discuss details of the computational method. Partition functions are given in wide range of temperatures, 10^3 K < T < 10^6 K, and lowering of ionization energy ... More
Antibaryon-nucleus bound statesNov 27 2014We calculated antibaryon ($\bar{B}$ = $\bar{p}$, $\bar{\Lambda}$, $\bar{\Sigma}$, $\bar{\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{B}$-meson coupling constants were scaled to yield ... More
On Electro-weak mixing derived from radiative corrections and the necessity of the Higgs mechanismJun 12 1996Jun 20 1996Starting from the unmixed Lagrangian, the electro-weak radiative corrections are recomputed using symmetrical generalised functions. All gauge bosons acquire an indeterminate mass. Electro-weak mixing is obtained by diagonalization of the mass matrix. ... More
Quantum-Electrodynamics without renormalization V. Bosonic contributions to the photon massMay 11 1994The bosonic contributions to the photon mass are shown to be of the same form as the fermionic contributions, but of opposite sign. A mass sum rule for bosons and fermions follows from gauge invariance. Assuming completeness of the standard model the ... More
XMM-Newton Data Processing for Faint Diffuse Emission: Proton Flares, Exposure Maps and Report on EPIC MOS1 Bright CCDs ContaminationAug 04 2005We present a study of the in-flight performance of the XMM-Newton EPIC MOS and pn detectors, with focus on the influence of proton flares and vignetting on the data. The very wide range in the conditions of our sample of observations, in terms of exposure ... More
Primordial fluctuations without scalar fieldsJul 10 2009Jan 29 2010We revisit the question of whether fluctuations in hydrodynamical, adiabatical matter could explain the observed structures in our Universe. We consider matter with variable equation of state $w=p_0/\ep_0$ and a concomitant (under the adiabatic assumption) ... More
Efficiency of the SQUID Ratchet Driven by External CurrentFeb 19 2015We study theoretically the efficiency of an asymmetric superconducting quantum interference device (SQUID) which is constructed as a loop with three capacitively and resistively shunted Josephson junctions. Two junctions are placed in series in one arm ... More
Solution of the Skyrme-Hartree-Fock equations in the Cartesian deformed harmonic oscillator basis. (II) The program HFODDNov 17 1996We describe the code HFODD which solves the nuclear Skyrme-Hartree-Fock problem by using the deformed Cartesian harmonic oscillator basis. The user has a possibility of choosing among various symmetries of the nuclear HF problem for rotating or non-rotating ... More
High-Order Coupled Cluster Method (CCM) Formalism 3: Finite-Size CCMFeb 23 2010Recent 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, and independently to "generalised" expectation values for a wide range of one- and two-body spin operators. ... More
High-Order Coupled Cluster Method (CCM) Formalism 1: Ground- and Excited-State Properties of Lattice Quantum Spin Systems with $s >= 1/2$Sep 07 2009Sep 11 2009The coupled cluster method (CCM) is a powerful and widely applied technique of modern-day quantum many-body theory. It has been used with great success in order to understand the properties of quantum magnets at zero temperature. This is due largely to ... More
Neon Insights from Old Solar X-rays: a Plasma Temperature Dependence of the Coronal Neon ContentSep 16 2011An analysis using modern atomic data of fluxes culled from the literature for O VIII and Ne IX lines observed in solar active regions by the P78 and Solar Maximum Mission satellites confirms that the coronal Ne/O abundance ratio varies by a factor of ... More
Horizons in de-Sitter SupergravityJan 14 2010Nov 26 2010We classify all pseudo-supersymmetric extremal near-horizon geometries in minimal five-dimensional de-Sitter supergravity. It is shown that the only such near-horizon geometry is the near-horizon geometry of the de-Sitter BMPV solution, and hence there ... More
Second order Contact of Minimal SurfacesJan 18 2002The minimal surface equation $Q$ in the second order contact bundle of $R^3$, modulo translations, is provided with a complex structure and a canonical vector-valued holomorphic differential form $Omega$ on $Q\0$. The minimal surfaces $M$ in $R^3$ correspond ... More
Density Matrix Renormalisation Group Calculations for Two-Dimensional Lattices: An Application to the Spin-Half and Spin-One Square-Lattice Heisenberg ModelsSep 02 2003A new density matrix renormalisation group (DMRG) approach is presented for quantum systems of two spatial dimensions. In particular, it is shown that it is possible to create a multi-chain-type 2D DMRG approach which utilises previously determined system ... More
A logic-based approach to data integrationOct 16 2001An important aspect of data integration involves answering queries using various resources rather than by accessing database relations. The process of transforming a query from the database relations to the resources is often referred to as query folding ... More
Status and prospects of the NEXT experiment for neutrinoless double beta decay searchesJun 04 2019NEXT (Neutrino Experiment with a Xenon TPC) is an experimental program whose goals are to discover neutrinoless double beta decay using $^{136}$Xe in high pressure xenon TPCs with electroluminescent readout. In this paper, results from the NEXT-White ... More
Multiplicative noise and charge density wave dynamics in Rb0.30MoO3Jul 17 2012We have investigated the combined effects of a multiplicative noise and nonlinear conductivity on the charge density wave (CDW) dynamics of the quasi-one dimensional conductor Rb0.30MoO3. When the amplitude of a bipolar rectangular voltage pulse excitation ... More
Broad band noise and stochastic resonance in the CDW conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002)May 09 2012We have investigated nonlinear characteristics and broad band noise in the quasi-one dimensional charge-density-wave conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002) When the amplitude of a bipolar rectangular voltage pulse excitation is ... More
On Reasonable and Forced Goal Orderings and their Use in an Agenda-Driven Planning AlgorithmJun 01 2011The paper addresses the problem of computing goal orderings, which is one of the longstanding issues in AI planning. It makes two new contributions. First, it formally defines and discusses two different goal orderings, which are called the reasonable ... More
The Vapnik-Chervonenkis dimension of cubes in $\mathbb{R}^d$Dec 20 2014Nov 26 2017The Vapnik-Chervonenkis (VC) dimension of a collection of subsets of a set is an important combinatorial concept in settings such as discrete geometry and machine learning. In this paper we prove that the VC dimension of the family of $d$-dimensional ... More
Radon transformation on reductive symmetric spaces: support theoremsNov 26 2010Apr 03 2013We introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and study some of their properties. In particular we obtain a support theorem that generalizes Helgason's support theorem for the horospherical ... More
An inequality between multipoint Seshadri constantsApr 10 2008Let X be a projective variety of dimension n and L be a nef divisor on X. Denote by e_d(r;X,L) the d-dimensional Seshadri constant of r very general points in X. We prove that e_d(rs;X,L) >= e_d(r;X,L)e_d(s;P^n,O_{P^n}(1)).
Origin of the quasi-universality of the graphene minimal conductivityApr 15 2010Sep 16 2010It is a fact that the minimal conductivity $\sigma_0$ of most graphene samples is larger than the well-established universal value for ideal graphene $4e^2/\pi h$; in particular, larger by a factor $\gtrsim\pi$. Despite intense theoretical activity, this ... More