Results for "M. Esposito"

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On The Weak-Coupling Limit for Bosons and FermionsMar 16 2005In this paper we consider a large system of Bosons or Fermions. We start with an initial datum which is compatible with the Bose-Einstein, respectively Fermi-Dirac, statistics. We let the system of interacting particles evolve in a weak-coupling regime. ... More
Hydrodynamics of a driven lattice gas with open boundaries: the asymmetric simple exclusionFeb 08 2002We consider the asymmetric simple exclusion process in $d\ge 3$ with open boundaries. The particle reservoirs of constant densities are modeled by birth and death processes at the boundary. We prove that, if the initial density and the densities of the ... More
Lectures on Deformation quantization of Poisson manifoldsJul 13 2012Jul 18 2012These notes are based on the course given at the School of Geometry, University Kasdi Merbah (Ouargla) 2012. The aim of the course was the deformation quantization of Poisson Lie groups. In these notes we only review Kontsevich's formality theorem.
Poisson ReductionJun 20 2011Oct 09 2013In this paper we develope a theory of reduction for classical systems with Poisson Lie groups symmetries using the notion of momentum map introduced by Lu. The local description of Poisson manifolds and Poisson Lie groups and the properties of Lu's momentum ... More
Symmetry and monotonicity properties of singular solutions to some cooperative semilinear elliptic systems involving critical nonlinearitiesApr 08 2019Jul 14 2019We investigate qualitative properties of positive singular solutions of some elliptic systems in bounded and unbounded domains. We deduce symmetry and monotonicity properties via the moving plane procedure. Moreover, in the unbounded case, we study some ... More
Symmetry and monotonicity properties of singular solutions to some cooperative semilinear elliptic systems involving critical nonlinearityApr 08 2019We investigate qualitative properties of positive singular solutions of some elliptic systems in bounded and unbounded domains. We deduce symmetry and monotonicity properties via the moving plane procedure. Moreover, in the unbounded case, we study some ... More
Majorana transformation for differential equationsApr 19 2002We present a method for reducing the order of ordinary differential equations satisfying a given scaling relation (Majorana scale-invariant equations). We also develop a variant of this method, aimed to reduce the degree of non-linearity of the lower-order ... More
Infinite energy solutions to vortex equations governing the fractional quantum Hall effectOct 30 2018In this paper, we utilize weighted Sobolev spaces to establish an existence theory for infinite energy solutions to a coupled non-linear elliptic system. This system describes the fractional quantum Hall effect in two-dimensional double-layered systems. ... More
Droplet minimizers for the Gates-Lebowitz-Penrose free energy functionalMay 21 2009We study the structure of the constrained minimizers of the Gates-Lebowitz-Penrose free-energy functional ${\mathcal F}_{\rm GLP}(m)$, non-local functional of a density field $m(x)$, $x\in {\mathcal T}_L$, a $d$-dimensional torus of side length $L$. At ... More
Droplet minimizers for the Cahn Hilliard free energy functionalMay 11 2005We prove theorem characterizing the minimizers in a model for condensation based on the Cahn Hilliard free energy functional. In particular, we exactly determine the critical density for droplet formation.
Long term spectral variability in the soft gamma ray repeater SGR 1900+14Dec 29 2006Jan 09 2007We present a systematic analysis of all the BeppoSAX data of SGR 1900+14. The observations spanning five years show that the source was brighter than usual on two occasions: ~20 days after the August 1998 giant flare and during the 10^5 sec long X-ray ... More
Field theoretic description of the abelian and non-abelian Josephson effectMay 14 2007We formulate the Josephson effect in a field theoretic language which affords a straightforward generalization to the non-abelian case. Our formalism interprets Josephson tunneling as the excitation of pseudo-Goldstone bosons. We demonstrate the formalism ... More
Five years of SGR 1900+14 observations with BeppoSAXSep 04 2006We present a systematic analysis of all the BeppoSAX data of the soft gamma-ray repeater SGR 1900+14: these observations allowed us to study the long term properties of the source quiescent emission. In the observation carried out before the 1998 giant ... More
Perturbative evaluation of scalar two-point function in the cosmic microwave background power spectrumFeb 14 2014Mar 20 2014Recent work in the literature has found a suppression or, instead, an enhancement of the Cosmic Microwave Background power spectrum in quantum gravity, although the effect is too small to be observed, in both cases. The present paper studies in detail ... More
A concise introduction to trapped surface formation in general relativityMay 04 2017May 10 2017Trapped surface formation in general relativity can be studied through a coupled set of nonlinear equations, where various terms can be neglected, as was proved by a rigorous mathematical analysis of Christodoulou. This paper is devoted to a pedagogical ... More
Singular mean field equations on compact Riemann surfacesOct 23 2012Apr 30 2014For a general class of elliptic PDE's in mean field form on compact Riemann surfaces with exponential nonlinearity, we address the question of the existence of solutions with concentrated nonlinear term, which, in view of the applications, are physically ... More
Affine hyperplane arrangements and Jordan classesJul 27 2018We study the geometry of the stratification induced by an affine hyperplane arrangement $H$ on the quotient of a complex affine space by the action of a group preserving $H$. We give conditions ensuring normality of strata. As an application, we determine ... More
Majorana, Pauling and the quantum theory of the chemical bondJun 26 2013We discuss in detail very little known results obtained by Majorana as early as 1931, regarding the quantum theory of the chemical bond in homopolar molecules, based on the key concept of exchange interaction. After a brief historical overview of the ... More
Quantum interferences reconstruction with low homodyne detection efficiencyAug 31 2015Standard quantum state reconstruction techniques indicate that a detection efficiency of $0.5$ is an absolute threshold below which quantum interferences cannot be measured. However, alternative statistical techniques suggest that this threshold can be ... More
Towards obtaining Green functions for a Casimir cavity in de Sitter spacetimeSep 22 2014Dec 02 2014Recent work in the literature has studied rigid Casimir cavities in a weak gravitational field, or in de Sitter spacetime, or yet other spacetime models. The present review paper studies the difficult problem of direct evaluation of scalar Green functions ... More
Work producing reservoirs: Stochastic thermodynamics with generalized Gibbs ensemblesJul 29 2016We develop a consistent stochastic thermodynamics for environments composed of thermodynamic reservoirs in an external conservative force field, that is environments described by the Generalized or Gibbs canonical ensemble. We demonstrate that small systems ... More
Thermodynamics with continuous information flowFeb 13 2014Jun 30 2014We provide a unified thermodynamic formalism describing information transfers in autonomous as well as nonautonomous systems described by stochastic thermodynamics. We demonstrate how information is continuously generated in an auxiliary system and then ... More
Geometry and physics of pseudodifferential operators on manifoldsSep 18 2015Mar 08 2016A review is made of the basic tools used in mathematics to define a calculus for pseudodifferential operators on Riemannian manifolds endowed with a connection: esistence theorem for the function that generalizes the phase; analogue of Taylor's theorem; ... More
Calibration of the cross-resonance two-qubit gate between directly-coupled transmonsMay 14 2019Quantum computation requires the precise control of the evolution of a quantum system, typically through application of discrete quantum logic gates on a set of qubits. Here, we use the cross-resonance interaction to implement a gate between two superconducting ... More
Quadrature With Respect to Binomial MeasuresDec 07 2006Mar 19 2008This work is devoted to the study of integration with respect to binomial measures. We develop interpolatory quadrature rules and study their properties. Local error estimates for these rules are derived in a general framework.
Testing for Preferred-Frame Effects in Gravity with Artificial Earth SatellitesNov 29 1993As gravity is a long-range force, one might a priori expect the Universe's global matter distribution to select a preferred rest frame for local gravitational physics. At the post-Newtonian approximation, two parameters suffice to describe the phenomenology ... More
An analytic approach to the Riemann hypothesisFeb 07 2019In this work we consider a new functional equation for the Riemann zeta-function in the critical half-strip. With the help of this equation we prove that finding non-trivial zeros of the Riemann zeta-function outside the critical line would be equivalent ... More
Radiation Induced Fermion ResonanceMar 27 1998The Dirac equation is solved for two novel terms which describe the interaction energy between the half integral spin of a fermion and the classical, circularly polarized, electromagnetic field. A simple experiment is suggested to test the new terms and ... More
Phase time and transmission probability in the traversal of a PT-symmetric potential: the case of an electromagnetic waveguideOct 02 2017We study the unconventional transmission properties of a wave-packet through a PT-symmetric potential region, as describing actual electromagnetic wave propagation along a waveguide filled with gain and loss media. The non-trivial behavior of the transmission ... More
Zirconia UV-curable colloids for additive manufacturing via hybrid inkjet printing-stereolithographyMar 18 2019Currently, additive manufacturing of ceramics by stereolithography (SLA) is limited to single materials and by a poor thickness resolution that strongly depends on the ceramic particles-UV light interaction. Combining selective laser curing with inkjet ... More
On the relation between event-based and time-based current statisticsSep 23 2009Mar 01 2010Current statistics can be calculated in various ways. Event-based approaches use the statistics of the number of events occuring during a given time. Time-based approaches use the statistics of the time needed to reach a given number of events. By analyzing ... More
Hunting for planets in the HL Tau diskSep 20 2015Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a gravitationally unstable ... More
Energy-momentum tensor of a Casimir apparatus in a weak gravitational field: scalar caseMar 06 2008Recent work in the literature had evaluated the energy-momentum tensor of a Casimir apparatus in a weak gravitational field, for an electromagnetic field subject to perfect conductor boundary conditions on parallel plates. The Casimir apparatus was then ... More
Energy-momentum tensor for a scalar Casimir apparatus in a weak gravitational field: Neumann conditionsOct 16 2008Nov 03 2008We consider a Casimir apparatus consisting of two perfectly conducting parallel plates, subject to the weak gravitational field of the Earth. The aim of this paper is the calculation of the energy-momentum tensor of this system for a free, real massless ... More
Majorana and the theoretical problem of photon-electron scatteringJan 27 2015Relevant contributions by Majorana regarding Compton scattering off free or bound electrons are considered in detail, where a (full quantum) generalization of the Kramers-Heisenberg dispersion formula is derived. The role of intermediate electronic states ... More
Nonlinear degenerate cross-diffusion systems with nonlocal interactionOct 04 2017We investigate a class of systems of partial differential equations with nonlinear cross-diffusion and nonlocal interactions, which are of interest in several contexts in social sciences, finance, biology, and real world applications. Assuming a uniform ... More
Achieving Large, Tunable Strain in Monolayer Transition-Metal DichalcogenidesMay 15 2017We describe a facile technique based on polymer encapsulation to apply several percent controllable strains to monolayer and few-layer Transition Metal Dichalcogenides (TMDs). We use this technique to study the lattice response to strain via polarized ... More
Gravitational waves about curved backgrounds: a consistency analysis in de Sitter spacetimeMay 05 2008Dec 21 2008Gravitational waves are considered as metric perturbations about a curved background metric, rather than the flat Minkowski metric since several situations of physical interest can be discussed by this generalization. In this case, when the de Donder ... More
The effect of linear perturbations on the Yamabe problemOct 30 2012In conformal geometry, the Compactness Conjecture asserts that the set of Yamabe metrics on a smooth, compact, aspherical Riemannian manifold (M,g) is compact. Established in the locally conformally flat case by Schoen [43,44] and for n\leq 24 by Khuri-Marques-Schoen ... More
Strengthened Information-theoretic Bounds on the Generalization ErrorMar 09 2019The following problem is considered: given a joint distribution $P_{XY}$ and an event $E$, bound $P_{XY}(E)$ in terms of $P_XP_Y(E)$ (where $P_XP_Y$ is the product of the marginals of $P_{XY}$) and a measure of dependence of $X$ and $Y$. Such bounds have ... More
Quantum phase excitations in Ginzburg-Landau superconductorsNov 15 2004We give a straightforward generalization of the Ginzburg-Landau theory for superconductors where the scalar phase field is replaced by an antisymmetric Kalb-Ramond field. We predict that at very low temperatures, where quantum phase effects are expected ... More
Modelling Stock-market Investors as Reinforcement Learning Agents [Correction]Sep 20 2016Decision making in uncertain and risky environments is a prominent area of research. Standard economic theories fail to fully explain human behaviour, while a potentially promising alternative may lie in the direction of Reinforcement Learning (RL) theory. ... More
On the mean field equation with variable intensities on pierced domainsMar 30 2019We consider the two-dimensional mean field equation of the equilibrium turbulence with variable intensities and Dirichlet boundary condition on a pierced domain $$\left\{ \begin{array}{ll} -\Delta u=\lambda_1\dfrac{V_1 e^{u}}{ \int_{\Omega_{\boldsymbol\epsilon}} ... More
Planets of young stars: the TLS radial velocity surveyOct 14 2005We report on the search for planets orbiting 46 nearby young stars performed at the State Observatory of Turingia (TLS) by means of a radial velocity survey. The aim of this program is to test the theories of formation/evolution of planetary systems. ... More
The Diverse Club: The Integrative Core of Complex NetworksJan 04 2017Jun 27 2017A complex system can be represented and analyzed as a network, where nodes represent the units of the network and edges represent connections between those units. For example, a brain network represents neurons as nodes and axons between neurons as edges. ... More
Web portals, instant messaging and web communities: new tools for online collaborationMay 26 2003Web portals are nowadays very popular. This type of web sites let users to share information, request advice or help in a particular field, and furthermore allow them to create and extend sites content. Combined with instant messaging systems, used to ... More
Some Considerations on the derivation of the nonlinear Quantum Boltzmann EquationJan 17 2003In this paper we analyze a system of N identical quantum particles in a weak-coupling regime. The time evolution of the Wigner transform of the one-particle reduced density matrix is represented by means of a perturbative series. The expansion is obtained ... More
Detection of continuum radio emission associated with GemingaFeb 23 2011Jun 15 2011A deep Very Large Array observation of the Geminga pulsar field led to the discovery, at a higher than 10 sigma significance level, of radio emission trailing the neutron star proper motion. This 10-arcsec-long radio feature, detected with a flux of 0.4 ... More
Micro-reversibility and thermalization with collisional bathsApr 16 2019Aug 12 2019Micro-reversibility, that is, the time reversal symmetry exhibited by microscopic dynamics, plays a central role in thermodynamics and statistical mechanics. It is used to prove fundamental results such as Onsager reciprocal relations or fluctuation theorems. ... More
FPGA code for the data acquisition and real-time processing prototype of the ITER Radial Neutron CameraJun 15 2018The main role of the ITER Radial Neutron Camera (RNC) diagnostic is to measure in real-time the plasma neutron emissivity profile at high peak count rates for a time duration up to 500 s. Due to the unprecedented high performance conditions and after ... More
A Decade of MWC 758 Disk Images: Where Are the Spiral-Arm-Driving Planets?Mar 19 2018Jun 19 2018Large-scale spiral arms have been revealed in scattered light images of a few protoplanetary disks. Theoretical models suggest that such arms may be driven by and co-rotate with giant planets, which has called for remarkable observational efforts to look ... More
OpenMosix approach to build scalable HPC farms with an easy management infrastructureMay 26 2003The OpenMosix approach is a good solution to build powerful and scalable computing farms. Furthermore an easy management infrastructure is implemented using diskless nodes and network boot procedures. In HENP environment, the choice of OpenMosix has been ... More
The High Mass X-ray Binaries in star-forming galaxiesNov 15 2018The high mass X-ray binaries (HMXBs) provide an exciting framework to investigate the evolution of massive stars and the processes behind binary evolution. HMXBs have shown to be good tracers of recent star formation in galaxies and might be important ... More
Evaluating current processors performance and machines stabilityMay 26 2003Accurately estimate performance of currently available processors is becoming a key activity, particularly in HENP environment, where high computing power is crucial. This document describes the methods and programs, opensource or freeware, used to benchmark ... More
Non equilibrium spectra of degenerate relic neutrinosMay 30 2000Sep 18 2000We calculate the exact kinetic evolution of cosmic neutrinos until complete decoupling, in the case when a large neutrino asymmetry exists. While not excluded by present observations, this large asymmetry can have relevant cosmological consequences and ... More
Micro-reversibility and thermalization with collisional bathsApr 16 2019Micro-reversibility, that is, the time reversal symmetry exhibited by microscopic dynamics, plays a central role in thermodynamics and statistical mechanics. It is used to prove fundamental results such as Onsager reciprocal relations or fluctuation theorems. ... More
Spectral synthesis analysis and radial velocity study of the northern F-, G-, and K-type flare-starsNov 08 2005In this publication we present a study of the general physical, chemical properties and radial velocity monitoring of young active stars. We derive temperatures, log g, [Fe/H], v sin i, and R_{spec} values for eight stars. The detailed analysis reveals ... More
Standard FTP and GridFTP protocols for international data transfer in Pamela Satellite Space ExperimentMay 27 2003Physics applications often involve large amounts of data and/or computing and often require secure resource sharing across organizational boundaries, and are thus not easily handled by today's Internet and Web infrastructures. Pamela (a Payload Antimatter ... More
The 100-month Swift catalogue of supergiant fast X-ray transients I. BAT on-board and transient monitor flaresDec 17 2013Jan 07 2014We investigate the characteristics of bright flares for a sample of supergiant fast X-ray transients and their relation to the orbital phase. We have retrieved all Swift/BAT Transient Monitor light curves, and collected all detections in excess of $5\sigma$ ... More
A Personal Point of View about Scientific Discussions on Free WillFeb 15 2012I briefly present a personal view about alleged scientific results on free will.
Fermi at Los Alamos and the early Britain's way to nuclear energyMay 02 2008A novel recovery of some important documents related to the Fermi course on neutron physics, held at Los Alamos in 1945, is announced. Its relevance for the effective launch of a British nuclear programme in the early postwar period, independently of ... More
Four variations on Theoretical Physics by Ettore MajoranaApr 07 2006An account is given of some topical unpublished work by Ettore Majorana, revealing his very deep intuitions and skilfulness in Theoretical Physics. The relevance of the quite unknown results obtained by him is pointed out as well.
An unknown story: Majorana and the Pauli-Weisskopf scalar electrodynamicsOct 31 2007An account is given of an interesting but unknown theory by Majorana regarding scalar quantum electrodynamics, elaborated several years before the known Pauli-Weisskopf theory. Theoretical calculations and their interpretation are given in detail, together ... More
The action of neutrino ponderomotive force on supernova dynamicsFeb 16 1999Sep 02 1999Collective interactions of a beam of neutrinos/antineutrinos traversing a dense magnetized plasma of electrons/positrons, protons and neutrons are studied with particular reference to the case of a Supernova. We find that the ponderomotive force exerted ... More
Complex Parameters in Quantum MechanicsJul 21 1998Nov 04 1998The Schrodinger equation for stationary states in a central potential is studied in an arbitrary number of spatial dimensions, say q. After transformation into an equivalent equation, where the coefficient of the first derivative vanishes, it is shown ... More
Mathematical Structures of Space-TimeJul 01 1995At first we introduce the space-time manifold and we compare some aspects of Riemannian and Lorentzian geometry such as the distance function and the relations between topology and curvature. We then define spinor structures in general relativity, and ... More
Non-Fuchsian Singularities in Quantum MechanicsJan 02 1999Oct 13 1999A modification of the spiked harmonic oscillator is studied in the case for which the perturbation potential contains both an inverse power and a linear term. It is then possible to evaluate trial functions by solving an integral equation due to the occurrence ... More
Non-Local Boundary Conditions in Euclidean Quantum GravityJun 12 1998Dec 16 1998Non-local boundary conditions for Euclidean quantum gravity are proposed, consisting of an integro-differential boundary operator acting on metric perturbations. In this case, the operator P on metric perturbations is of Laplace type, subject to non-local ... More
Euclidean Maxwell Theory in the Presence of BoundariesJun 26 1995This paper describes recent progress in the analysis of relativistic gauge conditions for Euclidean Maxwell theory in the presence of boundaries. The corresponding quantum amplitudes are studied by using Faddeev-Popov formalism and zeta-function regularization, ... More
New Perspectives in Complex General RelativityJun 07 1995In complex general relativity, Lorentzian space-time is replaced by a four-complex-dimensional complex-Riemannian manifold, with holomorphic connection and holomorphic curvature tensor. A multisymplectic analysis shows that the Hamiltonian constraint ... More
Compact Tetraquark Interpretation of the XYZ StatesDec 14 2015The past decade witnessed the observation of several exotic charmonium-like resonances, some of which are manifestly non-qqbar mesons. We review one of the most popular interpretations of such states: the compact tetraquark in the constituent diquark-antidiquark ... More
On the classical and quantum momentum mapMar 19 2012In this thesis we study the classical and quantum momentum maps and the theory of reduction. We focus on the notion of momentum map in Poisson geometry and we discuss the classification of the momentum map in this framework. Furthermore, we describe the ... More
The Neumann eigenvalue problem for the $\infty$-LaplacianMay 14 2014Sep 22 2014The first nontrivial eigenfunction of the Neumann eigenvalue problem for the $p$-Laplacian, suitable normalized, converges as $p$ goes to $\infty$ to a viscosity solution of an eigenvalue problem for the $\infty$-Laplacian. We show among other things ... More
Quantization of Poisson-Hamiltonian systemsFeb 26 2015In this paper we introduce the concept of Hamiltonian system in the canonical and Poisson settings. We will discuss the quantization of the Hamiltonian systems in the Poisson context, using formal deformation quantization and quantum group theories.
Ettore Majorana and his heritage seventy years laterMar 25 2008The physicists working in several areas of research know quite well the name of Ettore Majorana, since it is currently associated to fundamental concepts like {\it Majorana neutrinos} in particle physics and cosmology or {\it Majorana fermions} in condensed ... More
Majorana solution of the Thomas-Fermi equationNov 22 2001We report on an original method, due to Majorana, leading to a semi-analytical series solution of the Thomas-Fermi equation, with appropriate boundary conditions, in terms of only one quadrature. We also deduce a general formula for such a solution which ... More
An introduction to quantum gravityAug 16 2011Quantum gravity was born as that branch of modern theoretical physics that tries to unify its guiding principles, i.e., quantum mechanics and general relativity. Nowadays it is providing new insight into the unification of all fundamental interactions, ... More
A new application of non-canonical maps in quantum mechanicsSep 07 2001Oct 22 2001A proof is given that an invertible and a unitary operator can be used to reproduce the effect of a q-deformed commutator of annihilation and creation operators. In other words, the original annihilation and creation operators are mapped into new operators, ... More
Towards a Spectral Proof of the Mass Gap in QCD?Jul 09 2001Nov 26 2001Yang--Mills theory in four dimensions is studied by using the Coulomb gauge. The Coulomb gauge Hamiltonian involves integration of matrix elements of an operator P built from the Laplacian and from a first-order differential operator. The operator P is ... More
Local Boundary Conditions in Quantum SupergravityAug 12 1996When quantum supergravity is studied on manifolds with boundary, one may consider local boundary conditions which fix on the initial surface the whole primed part of tangential components of gravitino perturbations, and fix on the final surface the whole ... More
Non-Local Properties in Euclidean Quantum GravityAug 28 1995Sep 24 1995In the one-loop approximation for Euclidean quantum gravity, the boundary conditions which are completely invariant under gauge transformations of metric perturbations involve both normal and tangential derivatives of the metric perturbations $h_{00}$ ... More
The Geometry of Complex Space-Times with TorsionAug 14 1995The necessary and sufficient condition for the existence of $\alpha$-surfaces in complex space-time manifolds with nonvanishing torsion is derived. For these manifolds, Lie brackets of vector fields and spinor Ricci identities contain explicitly the effects ... More
Singularity Theory in Classical CosmologyJul 01 1995This paper compares recent approaches appearing in the literature on the singularity problem for space-times with nonvanishing torsion.
A classification result for the quasi-linear Liouville equationSep 12 2016Entire solutions of the $n-$Laplace Liouville equation in $\mathbb{R}^n$ with finite mass are completely classified.
Equilibria of a clamped Euler beam (Elastica) with distributed load: large deformationsOct 25 2016Mar 21 2017We present some novel equilibrium shapes of a clamped Euler beam (Elastica from now on) under uniformly distributed dead load orthogonal to the straight reference configuration. We characterize the properties of the minimizers of total energy, determine ... More
The ERIS Adaptive Optics SystemJul 23 2016ERIS is the new AO instrument for VLT-UT4 led by a Consortium of Max-Planck Institut fuer Extraterrestrische Physik, UK-ATC, ETH-Zurich, ESO and INAF. The ERIS AO system provides NGS mode to deliver high contrast correction and LGS mode to extend high ... More
Minimum light transmission in graphene in the presence of a magnetic fieldNov 04 2015We show that, on general theoretical grounds, transmission of light in graphene always presents a non-vanishing minimum value independently of any material and physical condition, the transmission coefficient being higher in the presence of a substrate, ... More
Physical realization of Photonic Klein TunnelingJan 18 2011General physical conditions for the occurrence of photonic Klein tunneling are studied, where (controlled) spontaneous emission from the devices considered plays a key role. The specific example of a simple dielectric slab bounded by two dielectric half ... More
A theory of ferromagnetism by Ettore MajoranaMay 20 2008We present and analyze in detail an unknown theory of ferromagnetism developed by Ettore Majorana as early as the beginnings of 1930s, substantially different in the methods employed from the well-known Heisenberg theory of 1928 (and from later formulations ... More
Un manoscritto inedito in francese di Ettore MajoranaJul 11 2006We report on the retrieval of the last missing papers of the "Senatore folder", given by Majorana to one student of his in Naples in 1938, just before his disappearance. The mentioned manuscript is conserved at the Domus Galilaeana in Pisa (Italy), and ... More
Una lezione particolare di Ettore MajoranaDec 19 2005We give, for the first time, the critical complete text of a manuscript by Ettore Majorana, conserved in the same file of the lecture notes for his course on Theoretical Physics at the University of Naples. He probably refers to a seminar delivered in ... More
The effect of very low energy solar neutrinos on the MSW mechanismNov 07 2003We study some implications on standard matter oscillations of solar neutrinos induced by a background of extremely low energy thermal neutrinos trapped inside the Sun by means of coherent refractive interactions. Possible experimental tests are envisaged ... More
On the role of Spin in Quantum MechanicsFeb 05 1999From the invariance properties of the Schrodinger equation and the isotropy of space we show that a generic (non-relativistic) quantum system is endowed with an ``external'' motion, which can be interpreted as the motion of the centre of mass, and an ... More
Primordial Nucleosynthesis: accurate predictions for light element abundancesApr 29 1999A detailed analysis of primordial nucleosynthesis predictions for light element abundances is performed. Contents: 1. The standard cosmology: an overview. 2. Primordial nucleosynthesis. 3. The Born rates for n<->p reactions. 4. Finite nucleon mass corrections. ... More
Covariant Majorana Formulation of ElectrodynamicsApr 21 1997We construct an explicit covariant Majorana formulation of Maxwell electromagnetism which does not make use of vector 4-potential. This allows to write a ``Dirac'' equation for the photon containing all the known properties of it. In particular, the spin ... More
A spinorial perspective on massless photonsJan 02 2007We exploit the fact that, in Minkowski space-time, gamma matrices are possibly more fundamental than the metric to describe how gauge invariance at perturbative level enforces a Lagrangian for spinor electrodynamics with massless photons. The term quadratic ... More
New Photon Propagators in Quantum ElectrodynamicsNov 25 2005A Lagrangian for quantum electrodynamics is found which makes it explicit that the photon mass is eventually set to zero in the physical part on observational ground. It remains possible to obtain a counterterm Lagrangian where the only non-gauge-invariant ... More
Quantum cosmology from three different perspectivesMay 10 2006Our review is devoted to three promising research lines in quantum cosmology and the physics of the early universe. The nonperturbative renormalization programme is making encouraging progress that we here assess from the point of view of cosmological ... More
From Spinor Geometry to Complex General RelativityApr 11 2005May 23 2005An attempt is made of giving a self-contained (although incomplete) introduction to holomorphic ideas in general relativity, following work over the last thirty years by several authors. The main topics are complex manifolds, two-component spinor calculus, ... More
Spectral Properties of Yang-Mills TheorySep 21 2001Jun 16 2005This paper was withdrawn. It has been superseded by the latest version of hep-th/0107069.