Results for "F. Califano"

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Shear layer instability in a highly diffusive stably stratified atmosphereAug 17 1999The linear stability of a shear layer in a highly diffusive stably stratified atmosphere has been investigated. This study completes and extends previous works by Dudis (1974) and Jones (1977). We show that: (i) an asymptotic regime is reached in the ... More
Kinetic cascade in solar-wind turbulence: 3D3V hybrid-kinetic simulations with electron inertiaJul 26 2017Oct 18 2017Understanding the nature of the turbulent fluctuations below the ion gyroradius in solar-wind turbulence is a great challenge. Recent studies have been mostly in favor of kinetic Alfv\'en wave (KAW) type of fluctuations, but other kinds of fluctuations ... More
Searching for Gene Sets with Mutually Exclusive MutationsSep 18 2016Cancer cells evolve through random somatic mutations. "Beneficial" mutations which disrupt key pathways (e.g. cell cycle regulation) are subject to natural selection. Multiple mutations may lead to the same "beneficial" effect, in which case there is ... More
Turbulent dynamo in a collisionless plasmaDec 20 2015Apr 01 2016Magnetic fields pervade the entire Universe and affect the formation and evolution of astrophysical systems from cosmological to planetary scales. The generation and dynamical amplification of extragalactic magnetic fields through cosmic times, up to ... More
Theory and applications of the Vlasov equationFeb 12 2015Feb 20 2015Forty articles have been recently published in EPJD as contributions to the topical issue "Theory and applications of the Vlasov equation". The aim of this topical issue was to provide a forum for the presentation of a broad variety of scientific results ... More
Pressure anisotropy generation in a magnetized plasma configuration with a shear flow velocityDec 09 2015The nonlinear evolution of the Kelvin Helmholtz instability in a magnetized plasma with a perpendicular flow close to, or in, the supermagnetosonic regime can produce a significant parallel-to-perpendicular pressure anisotropy. This anisotropy, localized ... More
Dual phase-space cascades in 3D hybrid-Vlasov-Maxwell turbulenceFeb 16 2018Mar 08 2018To explain energy dissipation via turbulence in collisionless, magnetized plasmas, the existence of a dual real- and velocity-space cascade of ion-entropy fluctuations below the ion gyroradius has been proposed. Such a dual cascade, predicted by the gyrokinetic ... More
Low energy Langmuir cavitons: asymptotic limit of weak turbulenceJan 14 2013Jan 15 2013Langmuir turbulence is an archetype of wave turbulence in plasma physics. By means of 1D-1V Vlasov-Poisson simulations, we show that coherent structures, called Langmuir cavitons, are generated by the long time evolution of Langmuir weak turbulence, thus ... More
Vlasov simulations of Langmuir Electrostatic Decay and consequences for Type III observationsJan 14 2013The electrostatic decay enables energy transfer from a finite amplitude Langmuir to a backscattered daughter Langmuir wave and ion acoustic density fluctuations. This mechanism is thought to be a first step for the generation of type III solar radio emissions ... More
Subproton-scale cascades in solar wind turbulence: driven hybrid-kinetic simulationsApr 26 2016A long-lasting debate in space plasma physics concerns the nature of subproton-scale fluctuations in solar wind (SW) turbulence. Over the past decade, a series of theoretical and observational studies were presented in favor of either kinetic Alfv\'en ... More
Pressure tensor in the presence of velocity shear: stationary solutions and self-consistent equilibriaOct 06 2014Oct 30 2014Observations and numerical simulations of laboratory and space plasmas in almost collisionless regimes reveal anisotropic and non-gyrotropic particle distribution functions. We investigate how such states can persist in the presence of a sheared flow. ... More
North-South asymmetric Kelvin-Helmholtz instability and induced reconnection at the Earth's magnetospheric flanksMay 03 2018We present a three-dimensional study of the plasma dynamics at the flank magnetopause of the Earth's magnetosphere during mainly northward interplanetary magnetic field (IMF) periods. Two-fluid simulations show that the initial magnetic shear at the magnetopause ... More
Electron-only magnetic reconnection in plasma turbulenceOct 09 2018We present hybrid-Vlasov-Maxwell (HVM) simulations of plasma turbulence including electron-inertia effects. When fluctuation energy is directly injected near ion-kinetic scales, the ions become de-magnetized around naturally forming electron-scale current ... More
Plasma turbulence at ion scales: a comparison between PIC and Eulerian hybrid-kinetic approachesMar 07 2017Kinetic-range turbulence in magnetized plasmas and, in particular, in the context of solar-wind turbulence has been extensively investigated over the past decades via numerical simulations. Among others, one of the widely adopted reduced plasma model ... More
Response to Comment on `Undamped electrostatic plasma waves' [Phys. Plasmas 19, 092103 (2012)]Feb 06 2013Numerical and experimental evidence is given for the occurrence of the plateau states and concomitant corner modes proposed in \cite{valentini12}. It is argued that these states provide a better description of reality for small amplitude off-dispersion ... More
Undamped electrostatic plasma wavesJun 15 2012Electrostatic waves in a collision-free unmagnetized plasma of electrons with fixed ions are investigated for electron equilibrium velocity distribution functions that deviate slightly from Maxwellian. Of interest are undamped waves that are the small ... More
Fully kinetic versus reduced-kinetic modelling of collisionless plasma turbulenceJun 08 2017Sep 20 2017We report the results of a direct comparison between different kinetic models of collisionless plasma turbulence in two spatial dimensions. The models considered include a first principles fully-kinetic (FK) description, two widely used reduced models ... More
Magnetic reconnection as a driver for a sub-ion scale cascade in plasma turbulenceJul 19 2017A new path for the generation of a sub-ion scale cascade in collisionless plasma turbulence, triggered by magnetic reconnection, is uncovered by means of high-resolution two-dimensional hybrid-kinetic simulations employing two complementary approaches, ... More
Proton Kinetic Effects in Vlasov and Solar Wind TurbulenceJun 27 2013Kinetic plasma processes have been investigated in the framework of solar wind turbulence, employing Hybrid Vlasov-Maxwell (HVM) simulations. The dependency of proton temperature anisotropy T_{\perp}/T_{\parallel} on the parallel plasma beta \beta_{\parallel}, ... More
ViDA: a Vlasov-DArwin solver for plasma physics at electron scalesMay 08 2019We present a Vlasov-DArwin numerical code (ViDA) specifically designed to address plasma physics problems, where small-scale high accuracy is requested even during the non linear regime to guarantee a clean description of the plasma dynamics at fine spatial ... More
Pressure anisotropy and small spatial scales induced by velocity shearJul 17 2015Non-Maxwellian metaequilibria can exist in low-collisionality plasmas as evidenced by satellite and laboratory measurements. By including the full pressure tensor dynamics in a fluid plasma model, we show that a sheared velocity field can provide an effective ... More
Tuning of the Gap in a Laughlin-Bychkov-Rashba Incompressible LiquidNov 19 2004We report on our investigation of the influence of Bychkov-Rashba spin-orbit interaction (SOI) on the incompressible Laughlin state. We find that experimentally obtainable values of the spin-orbit coupling strength can induce as much as a 25% increase ... More
Spin precession in a fractional quantum Hall state with spin-orbit couplingApr 12 2005Experimental attempts to realize spin-devices based on concepts derived from single-particle theoretical approaches have not been very successful yet. This raises the fundamental question of whether inter-electron interactions can be neglected in planar ... More
Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: from fluid to kinetic modelingOct 29 2013The nonlinear evolution of collisionless plasmas is typically a multi-scale process where the energy is injected at large, fluid scales and dissipated at small, kinetic scales. Accurately modelling the global evolution requires to take into account the ... More
A Pattern Discovery-Based Method for Detecting Multi-Locus Genetic AssociationMar 16 2007Methods to effectively detect multi-locus genetic association are becoming increasingly relevant in the genetic dissection of complex trait in humans. Current approaches typically consider a limited number of hypotheses, most of which are related to the ... More
Genome-wide discovery of modulators of transcriptional interactions in human B lymphocytesOct 15 2005Mar 02 2006Transcriptional interactions in a cell are modulated by a variety of mechanisms that prevent their representation as pure pairwise interactions between a transcription factor and its target(s). These include, among others, transcription factor activation ... More
Kinetic plasma turbulence during the nonlinear stage of the Kelvin-Helmholtz instabilityDec 03 2014Using a full kinetic, implicit particle-in-cell code, iPiC3D, we studied the properties of plasma kinetic turbulence, such as would be found at the interface between the solar wind and the Earth magnetosphere at low latitude during northwards periods. ... More
Coupling between whistler waves and slow-mode solitary wavesMar 17 2012The interplay between electron-scale and ion-scale phenomena is of general interest for both laboratory and space plasma physics. In this paper we investigate the linear coupling between whistler waves and slow magnetosonic solitons through two-fluid ... More
Multivariate dependence and genetic networks inferenceJan 11 2010A critical task in systems biology is the identification of genes that interact to control cellular processes by transcriptional activation of a set of target genes. Many methods have been developed to use statistical correlations in high-throughput datasets ... More
Vlasov-Poisson simulations of electrostatic parametric instability for localized Langmuir wave packets in the solar windJan 22 2013Recent observation of large amplitude Langmuir waveforms during a Type III event in the solar wind have been interpreted as the signature of the electrostatic decay of beam-driven Langmuir waves. This mechanism is thought to be a first step to explain ... More
Exploring the thermodynamic limit of Hamiltonian models: convergence to the Vlasov equationDec 08 2006Jan 13 2007We here discuss the emergence of Quasi Stationary States (QSS), a universal feature of systems with long-range interactions. With reference to the Hamiltonian Mean Field (HMF) model, numerical simulations are performed based on both the original $N$-body ... More
[Plasma 2020 Decadal] Disentangling the Spatiotemporal Structure of Turbulence Using Multi-Spacecraft DataMar 13 2019This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma turbulence. Plasma turbulence is ubiquitous in the universe, and it is responsible ... More
On The Reconstruction of Interaction Networks with Applications to Transcriptional RegulationOct 28 2004Sep 18 2005A novel information-theoretic method for reconstruction of interaction networks is introduced. We prove that the method is exact for some class of networks. Performance tests on large synthetic transcriptional regulatory networks produce very encouraging ... More
Conditional Network Analysis Identifies Candidate Regulator Genes in Human B CellsOct 30 2004Cellular phenotypes are determined by the dynamical activity of networks of co-regulated genes. Elucidating such networks is crucial for the understanding of normal cell physiology as well as for the dissection of complex pathologic phenotypes. Existing ... More
ARACNE: An Algorithm for the Reconstruction of Gene Regulatory Networks in a Mammalian Cellular ContextOct 28 2004Oct 07 2005Background: Elucidating gene regulatory networks is crucial for understanding normal cell physiology and complex pathologic phenotypes. Existing computational methods for the genome-wide ``reverse engineering'' of such networks have been successful only ... More
High-throughput validation of ceRNA regulatory networksJan 31 2017Background: MicroRNAs (miRNAs) play multiple roles in tumor biology [1]. Interestingly, reports from multiple groups suggest that miRNA targets may be coupled through competitive stoichiometric sequestration [2]. Specifically, computational models predicted ... More
On the breaking of a plasma wave in a thermal plasma: II. Electromagnetic wave interaction with the breaking plasma waveFeb 09 2012Apr 19 2012The structure of the density singularity formed in a relativistically large amplitude plasma wave close to the wavebreaking limit leads to a refraction coefficient which has a coordinate dependence with discontinuous derivatives. This results in a non-exponentially ... More
On the breaking of a plasma wave in a thermal plasma: I. The structure of the density singularityFeb 09 2012Apr 19 2012The structure of the singularity that is formed in a relativistically large amplitude plasma wave close to the wavebreaking limit is found by using a simple waterbag electron distribution function. The electron density distribution in the breaking wave ... More
Fokker-Planck and Quasilinear CodesJan 13 2005The interaction of radio-frequency waves with a plasma is described by a Fokker-Planck equation with an added quasilinear term. Methods for solving this equation on a computer are discussed.
Numerical Techniques for the Study of Long-Time CorrelationsJan 26 2004In the study of long-time correlations extremely long orbits must be calculated. This may be accomplished much more reliably using fixed-point arithmetic. Use of this arithmetic on the Cray-1 computer is illustrated.
Phase diagram of the half-filled two-dimensional SU(N) Hubbard-Heisenberg model: a quantum Monte Carlo studyJun 03 2004We investigate the phase diagram of the half-filled SU(N) Hubbard-Heisenberg model with hopping t, exchange J and Hubbard U, on a square lattice. In the large-N limit, and as a function of decreasing values of t/J, the model shows a transition from a ... More
Coherence scale of the two-dimensional Kondo Lattice modelJan 07 2004A doped hole in the two-dimensional half-filled Kondo lattice model with exchange J and hopping t has momentum (pi,pi) irrespective of the coupling J/t. The quasiparticle residue of the doped hole, Z_{(\pi, \pi)}, tracks the Kondo scale, T_K, of the corresponding ... More
UHECRs from the Radio Lobes of AGNsSep 23 2008Oct 07 2008We report a stochastic mechanism of particle acceleration from first principles in an environment having properties like those of Radio Lobes in AGNs. We show that energies $\sim 10^{20}$ eV are reached in $\sim 10^6$ years for protons. Our results reopen ... More
Taub, Rindler, and the static plateFeb 03 2005An infinite 3D plate of homogeneous incompressible fluid is considered, with finite thickness, together with a 2D infinite homogeneous mass in its centre. Einstein equations are exactly solved, in the interior of the 3D mass. The solution is joined to ... More
Separations inside a cubeDec 28 2001Two points are randomly selected inside a three-dimensional euclidian cube. The value l of their separation lies somewhere between zero and the length of a diagonal of the cube. The probability density P(l) of the separation is obtained analytically. ... More
Cosmic crystallography in a circleMay 15 2000Oct 05 2000In a circle (an S^1) with circumference 1 assume m objects distributed pseudo-randomly. In the universal covering R^1 assume the objects replicated accordingly, and take an interval L>1. In this interval, make the normalized histogram of the pair separations ... More
Synchronization of non-chaotic dynamical systemsAug 09 1999Dec 14 2000A synchronization mechanism driven by annealed noise is studied for two replicas of a coupled-map lattice which exhibits stable chaos (SC), i.e. irregular behavior despite a negative Lyapunov spectrum. We show that the observed synchronization transition, ... More
tbW vertex in the Littlest Higgs Model with T-parityOct 27 2008Feb 12 2009A study of the effective tbW vertex is done in the littlest Higgs model with T parity that includes the one loop induced weak dipole coefficient f_{2R}. The top's width, the W-boson helicity in the t-> bW^+ decay as well as the t-channel and the s-channel ... More
Non-Statistical gamma Rays from FragmentsOct 09 2007Polarization mechanism by Strutinsky-Denisov gives rise to the electric dipole radiation from fragments. Its probability calculated within the LDM turns out to be ~3.5x10-2 per fission. The radiation occurs during thermolization of the post-rupture deformation ... More
Stochastic Optimal Control with Delay in the Control II: Verification Theorem and Optimal FeedbacksJul 21 2016We consider a stochastic optimal control problem governed by a stochastic differential equation with delay in the control. Using a result of existence and uniqueness of a sufficiently regular mild solution of the associated Hamilton-Jacobi-Bellman (HJB) ... More
Measurement of wave-particle interaction and metastable lifetime using laser-induced fluorescenceFeb 27 2019Extensive information, such as ion temperature and wave-particle interactions, can be obtained by direct measurement of ion distribution functions using laser-induced fluorescence (LIF). This nonintrusive plasma diagnostic provides an important window ... More
Measurement of wave-particle interaction and metastable lifetime using laser-induced fluorescenceFeb 27 2019Apr 20 2019Extensive information, such as ion temperature and wave-particle interactions, can be obtained by direct measurement of ion distribution functions using laser-induced fluorescence (LIF). This nonintrusive plasma diagnostic provides an important window ... More
A hyperbolic analog of the phasor addition formulaNov 20 2014Feb 23 2017In this article we review the basics of the phasor formalism in a rigorous way, highlighting the physical motivation behind it and presenting a hyperbolic counterpart of the phasor addition formula.
Two- and three- dimensional few-body systems in the universal regimeNov 11 2014Macro properties of cold atomic gases are driven by few-body correlations, even if the gas has thousands of particles. Quantum systems composed of two and three particles with attractive zero\=/range pairwise interactions are considered for general masses ... More
SU(2)-spin Invariant Auxiliary Field Quantum Monte Carlo Algorithm for Hubbard modelsJun 25 1998Auxiliary field quantum Monte Carlo methods for Hubbard models are generally based on a Hubbard-Stratonovitch transformation where the field couples to the z-component of the spin. This transformation breaks SU(2) spin invariance. The symmetry is restored ... More
Adiabatic Magnetization of Superconductors as a High-Performance Cooling MechanismNov 25 2008The adiabatic magnetization of a superconductor is a cooling principle proposed in the 30s, which has never been exploited up to now. Here we present a detailed dynamic description of the effect, computing the achievable final temperatures as well as ... More
Hybrid superconducting quantum magnetometerMar 18 2011Dec 03 2011A superconducting quantum magnetometer based on magnetic flux-driven modulation of the density of states of a proximized metallic nanowire is theoretically analyzed. With optimized geometrical and material parameters transfer functions up to a few mV/Phi_0 ... More
Long-Time Correlations in the Stochastic RegimeJan 11 2005The phase space for Hamiltonians of two degrees of freedom is usually divided into stochastic and integrable components. Even when well into the stochastic regime, integrable orbits may surround small stable regions or islands. The effect of these islands ... More
Temporal Evolution of Lower Hybrid Waves in the Presence of Ponderomotive Density FluctuationsJan 10 2005The propagation of lower hybrid waves in the presence of ponderomotive density fluctuations is considered. The problem is treated in two dimensions and, in order to be able to correctly impose the boundary conditions, the waves are allowed to evolve in ... More
Algorithms for geodesicsSep 21 2011Mar 28 2012Algorithms for the computation of geodesics on an ellipsoid of revolution are given. These provide accurate, robust, and fast solutions to the direct and inverse geodesic problems and they allow differential and integral properties of geodesics to be ... More
Stochastic Optimal Control with Delay in the Control I: solving the HJB equation through partial smoothingJul 21 2016Stochastic optimal control problems governed by delay equations with delay in the control are usually more difficult to study than the the ones when the delay appears only in the state. This is particularly true when we look at the associated Hamilton-Jacobi-Bellman ... More
Experimentally obtaining metrics in general relativityMay 10 2005It seems to be not well known that the metrics of general relativity (GR) can be obtained without integrating Einstein equations. To that, we need only define a unit for GR-interval $\Delta s$, and observe 10 geodesics (out of which at least one must ... More
Right-Left Asymmetry of Radiation from FissionOct 09 2007The effect of the right-left asymmetry is considered in the predicted earlier electric dipole radiation from fission fragments arising due to the Strutinski-Denisov induced polarisation mechanism. The magnitude of the asymmetry parameter is on the level ... More
Gas accretion on spiral galaxies: bar formation and renewalJun 17 2002The effects of gas accretion on spiral disk dynamics and stability are studied through N-body simulations, including star formation and gas/stars mass exchange. The detailed processes of bar formation, bar destruction and bar re-formation are followed, ... More
Formation of polar ring galaxiesJan 20 2003Feb 04 2003Polar ring galaxies are peculiar systems in which a gas rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or ... More
Cosmology in massive conformal gravityOct 19 2014Sep 25 2015In this article we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative spatial curvature is in good agreement with our universe.
FCNC production of same sign Top quark pairs at the LHCNov 05 2003Nov 06 2003We study the possibility of same sign top quark pair production at the LHC (and the VLHC) as a direct probe of FCNC processes. Besides the SM neutral Z boson, two other neutral bosons are considered, a top-Higgs type scalar and a Z' boson that appear ... More
Collinear true ternary fission as the consequence of the collective nuclear modelApr 24 2019The concept of collinear spontaneous true ternary fission of 252Cf is subject to critical check by means of the trajectory calculations. The conclusion is that the collinear flight of the fragments turns out to be a natural and most probable mode. The ... More
A new geometrical approach to metric-affine gravityJul 16 2013Here we consider a metric-affine theory of gravity in which the gravitational Lagrangian is the scalar curvature. The matter action is allowed to depend also on the torsion and the nonmetricity, which are considered as the field variables together with ... More
Depleted Kondo LatticesApr 07 2001Nov 17 2001We consider a two dimensional Kondo lattice model with exchange J and hopping t in which three out of four impurity spins are removed in a regular way. At the particle-hole symmetric point the model may be studied with auxiliary field quantum Monte Carlo ... More
The interplay between d-wave superconductivity and antiferromagnetic fluctuations: a quantum Monte Carlo studyJun 25 1998We consider the repulsive Hubbard model on a square lattice with an additional term, W, which depends upon the square of a single-particle nearest-neighbor hopping. At half-band filling, constant W, we show that enhancing U/t drives the system from a ... More
Superconductors as ideal spin sources for spintronicsNov 05 2007Apr 03 2008Spin-polarized transport is investigated in normal metal-superconductor (NS) junctions as a function of interface transmissivity as well as temperature when the density of states of a superconductor is Zeeman-split in response to an exchange field (h_exc). ... More
Ultra-High-Energy Cosmic Rays from the Radio Lobes of AGNsSep 22 2008In the past year, the HiRes and Auger collaborations have reported the discovery of a high-energy cutoff in the ultra-high energy cosmic-ray (UHECR) spectrum, and an apparent clustering of the highest energy events towards nearby active galactic nuclei ... More
Sampling exactly from the normal distributionMar 25 2013Jun 10 2014An algorithm for sampling exactly from the normal distribution is given. The algorithm reads some number of uniformly distributed random digits in a given base and generates an initial portion of the representation of a normal deviate in the same base. ... More
Transverse Mercator with an accuracy of a few nanometersFeb 08 2010Feb 03 2011Implementations of two algorithms for the transverse Mercator projection are described; these achieve accuracies close to machine precision. One is based on the exact equations of Thompson and Lee and the other uses an extension of Krueger's series for ... More
Quaternions in molecular modelingJun 23 2005Apr 04 2006Quaternions are an important tool to describe the orientation of a molecule. This paper considers the use of quaternions in matching two conformations of a molecule, in interpolating rotations, in performing statistics on orientational data, in the random ... More
Long-Time Correlations in Stochastic SystemsJan 11 2005In recent years, there has been considerable interest in understanding the motion in Hamiltonian systems when phase space is divided into stochastic and integrable regions. This paper studies one aspect of this problem, namely, the motion of trajectories ... More
Exchange Monte Carlo for Molecular Simulations with Monoelectronic HamiltoniansMar 04 2002We introduce a general Monte Carlo scheme for achieving atomistic simulations with monoelectronic Hamiltonians including the thermalization of both nuclear and electronic degrees of freedom. The kinetic Monte Carlo algorithm is used to obtain the exact ... More
PINGSoft 2: an IDL Integral Field Spectroscopy Software, ready for the CALIFA survey dataNov 01 2012PINGSoft, is a set of IDL routines designed to visualise, manipulate, and analyse integral field spectroscopy (IFS) data regardless of the original instrument and spaxel shape. PINGSoft 2 is a relatively major upgrade with respect to the first version: ... More
Contraction Elimination in Sequent Based Ground Equational CalculusDec 30 2015In "Cut Elimination for Gentzen's Sequent Calculus with Equality and Logic of Partial Terms" LNCS 7750,161-172(2013), we have shown that the cut rule is eliminable in two ground equational sequent calculi, to be denoted by EQ_M and EQ'. In this note we ... More
Probing the unitarity of the renormalizable theory of massive conformal gravityJul 27 2017Apr 03 2018The presence of an unstable massive spin-2 ghost state in the renormalizable theory of massive conformal gravity leads to a pair of complex poles appearing in the first sheet of the energy plane. Here we show that the positions of these poles are gauge ... More
Reply to "Comment on 'Quantum massive conformal gravity' by F. F. Faria"Aug 03 2016Jan 07 2017Recently in (Eur. Phys. J. C 76:341, 2016) [arXiv:1604.08706], Myung has suggested that the renormalizability of massive conformal gravity is meaningless unless the massive ghost states of the theory are stable. Here we show that massive conformal gravity ... More
Cosmology in massive conformal gravityOct 19 2014Mar 06 2019In this paper we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative curvature is in good agreement with our universe.
Computation of Green's functions through algebraic decomposition of operatorsJul 04 2017In this article we use linear algebra to improve the computational time for the obtaining of Green's functions of linear differential equations with reflection (DER). This is achieved by decomposing both the `reduced' equation (the ODE associated to a ... More
Comment on the relation between the collinear tripartition and the collective model of the atomic nucleiApr 08 2019It is shown that the collinear tripartition in the case of spontaneous fission of 252Cf generically follows the principles of the collective Bohr's model. Qualitative consideration is supported by the numerical trajectory calculations.
Model pseudofermionic systems: connections with exceptional pointsFeb 25 2014We discuss the role of pseudo-fermions in the analysis of some two-dimensional models, recently introduced in connection with non self-adjoint hamiltonians. Among other aspects, we discuss the appearance of exceptional points in connection with the validity ... More
The acoustic spectrum of alpha Cen AJun 04 2002This paper presents the analysis of Doppler p-mode observations of the G2V star $\alpha$ Cen A obtained with the spectrograph CORALIE in May 2001. Thirteen nights of observations have made it possible to collect 1850 radial velocity measurements with ... More
PINGSoft: an IDL visualisation and manipulation tool for Integral Field Spectroscopic dataJun 04 2010In this article we introduce PINGSoft, a set of IDL routines designed to visualise and manipulate, in an interactive and friendly way, Integral Field Spectroscopic data. The package is optimised for large databases and a fast visualisation rendering. ... More
Spin, charge and single-particle spectral functions of the one-dimensional quarter filled Holstein modelJul 15 2008Sep 30 2008We use a recently developed extension of the weak coupling diagrammatic determinantal quantum Monte Carlo method to investigate the spin, charge and single particle spectral functions of the one-dimensional quarter-filled Holstein model with phonon frequency ... More
Upper and lower limits for the number of S-wave bound states in an attractive potentialOct 25 2002New upper and lower limits are given for the number of S-wave bound states yielded by an attractive (monotonic) potential in the context of the Schrodinger or Klein-Gordon equation.
Velocity-Space Diffusion in a Perpendicularly Propagating Electrostatic WaveJan 07 2005The motion of ions in the fields B = B_0 zhat and E = E_0 yhat cos(k_perp y - omega t) is considered. When omega >> Omega_i and v_perp > omega/k_perp, the equations of motion may be reduced to a set of difference equations. These equations exhibit stochastic ... More
Minimal Length Uncertainty Relation and gravitational quantum wellMay 18 2006The dynamics of a particle in a gravitational quantum well is studied in the context of nonrelativistic quantum mechanics with a particular deformation of a two-dimensional Heisenberg algebra. This deformation yields a new short-distance structure characterized ... More
Existence of mesons after deconfinementJun 27 2007Oct 24 2007We investigate the possibility for a quark-antiquark pair to form a bound state at temperatures higher than the critical one ($T>T_c$), thus after deconfinement. Our main goal is to find analytical criteria constraining the existence of such mesons. Our ... More
On the premelting features in sodium clustersDec 08 2003Melting in Na_n clusters described with an empirical embedded-atom potential has been reexamined in the size range 55<=n<=147 with a special attention at sizes close to 130. Contrary to previous findings, premelting effects are also present at such medium ... More
Interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs in Brans-Dicke cosmologyAug 29 2015Sep 29 2016In the framework of Brans-Dicke cosmology, we have studied the interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs. The Brans-Dicke parameter is investigated versus the conditions for the acceleration ... More
The ideal relativistic spinning gas: polarization and spectraOct 30 2007Feb 22 2008We study the physics of the ideal relativistic rotating gas at thermodynamical equilibrium and provide analytical expressions of the momentum spectra and polarization vector for the case of massive particles with spin 1/2 and 1. We show that the finite ... More
Reply to "Comment on 'Quantum massive conformal gravity' by F. F. Faria"Aug 03 2016Recently in Eur. Phys. J. C 76, 341 (2016) [arXiv:1604.08706] Myung has suggested that the problem with unphysical states in massive conformal gravity, which was pointed in Eur. Phys. J. C 76, 188 (2016), is solved if we quantize the dilaton field in ... More
Comment on "Astrophysical gravitational waves in conformal gravity"Feb 15 2019Recently, in Phys. Rev. D 98, 084002 (2018), an investigation was carried out on the gravitational radiation from binary systems in conformal gravity and massive conformal gravity. According to the authors of the paper, these two theories differ only ... More
Quantum massive conformal gravityMar 14 2015Apr 07 2016We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard ... More
Solar system tests for linear massive conformal gravityApr 08 2016We first find the linearized gravitational field of a static spherically symmetric mass distribution in massive conformal gravity. Then we test this field with two solar system experiments: deflection of light by the sun and radar echo delay. The result ... More