Results for "Gianluca Colò"

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Tensor interaction in mean-field and density functional theory approaches to nuclear structureJan 26 2014Jan 28 2014The importance of the tensor force for nuclear structure has been recognized long ago. Recently, the interest for this topic has been revived by the study of the evolution of nuclear properties far from the stability line. However, in the context of the ... More
Coulomb Energy Density Functionals for Nuclear Systems: Recent Studies of Coulomb Exchange and Correlation FunctionalsJul 10 2019The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock energy with ... More
Subtraction of the spurious translational mode from the RPA response functionAug 10 2011Dec 01 2011It is well known that within self-consistent Random Phase Approximation (RPA) on top of Hartree-Fock (HF), the translational symmetry should be restored. Due to approximations at the level of the practical implementation, this restoration may be only ... More
The Compression-Mode Giant Resonances and Nuclear IncompressibilityJan 11 2018Jan 30 2018The compression-mode giant resonances, namely the isoscalar giant monopole and isoscalar giant dipole modes, are examples of collective nuclear motion. Their main interest stems from the fact that one hopes to extrapolate from their properties the incompressibility ... More
Continuum particle-vibration coupling method in coordinate-space representation for finite nucleiMay 04 2012In this paper we present a new formalism to implement the nuclear particle-vibration coupling (PVC) model. The key issue is the proper treatment of the continuum, that is allowed by the coordinate space representation. Our formalism, based on the use ... More
Microscopic theory of the γ-decay of nuclear giant resonancesNov 02 2011Dec 14 2011In the past decades, the \gamma-decay of giant resonances has been studied using phenomenological models. In keeping with possible future studies performed with exotic beams, microscopically-based frameworks should be envisaged. In the present paper, ... More
Skyrme functional with tensor terms from ab initio calculationsOct 23 2018A new Skyrme functional devised to account well for standard nuclear properties as well as for spin and spin-isospin properties is presented. The main novelty of this work relies on the introduction of tensor terms guided by ab initio relativistic Brueckner-Hartree-Fock ... More
Regularization of zero-range effective interactions in finite nucleiOct 06 2014The problem of the divergences which arise in beyond mean-field calculations, when a zero-range effective interaction is employed, has not been much considered so far. Some of us have proposed, quite recently, a scheme to regularize a zero-range Skyrme-type ... More
Skyrme functional with tensor terms from \textit{ab initio} calculations of neutron-proton dropsOct 23 2018Mar 21 2019A new Skyrme functional devised to account well for standard nuclear properties as well as for spin and spin-isospin properties is presented. The main novelty of this work relies on the introduction of tensor terms guided by \textit{ab initio} relativistic ... More
Coulomb exchange functional with generalized gradient approximation for self-consistent Skyrme Hartree-Fock calculationsOct 05 2018Feb 14 2019We perform the self-consistent Skyrme Hartree-Fock calculation with the Coulomb exchange functional in the form of generalized gradient approximation (GGA). It is found that the Perdew-Burke-Ernzerhof GGA (PBE-GGA) Coulomb exchange functional is able ... More
Symmetry energy from the nuclear collective motion: constraints from dipole, quadrupole, monopole and spin-dipole resonancesSep 06 2013Dec 06 2013The experimental and theoretical studies of Giant Resonances, or more generally of the nuclear collective vibrations, are a well established domain in which sophisticated techniques have been introduced and firm conclusions reached after an effort of ... More
Nuclear single-particle states: dynamical shell model and energy density functional methodsJan 19 2010We discuss different approaches to the problem of reproducing the observed features of nuclear single-particle (s.p.) spectra. In particular, we analyze the dominant energy peaks, and the single-particle strength fragmentation, using the example of neutron ... More
Covariance analysis for Energy Density Functionals and instabilitiesJun 07 2014Oct 06 2014We present the covariance analysis of two successful nuclear energy density functionals, (i) a non-relativistic Skyrme functional built from a zero-range effective interaction, and (ii) a relativistic nuclear energy density functional based on density ... More
Beyond-mean-field theories with zero-range effective interactions. A way to handle the ultraviolet divergenceDec 14 2010Zero-range effective interactions are commonly used in nuclear physics and in other domains to describe many-body systems within the mean-field model. If they are used within a beyond-mean-field framework, contributions to the total energy that display ... More
Electric-magnetic deformations of D=4 gauged supergravitiesDec 14 2015We discuss duality orbits and symplectic deformations of D=4 gauged supergravity theories, with focus on N$\ge$2. We provide a general constructive framework for computing symplectic deformations starting from a reference gauging, and apply it to many ... More
Extreme Value Theory for Time Series using Peak-Over-Threshold methodSep 03 2015This brief paper summarize the chances offered by the Peak-Over-Threshold method, related with analysis of extremes. Identification of appropriate Value at Risk can be solved by fitting data with a Generalized Pareto Distribution. Also an estimation of ... More
Two-dimensional short-range interacting attractive and repulsive Fermi gases at zero temperatureMar 15 2013We study a two-dimensional two-component Fermi gas with attractive or repulsive short-range interactions at zero temperature. We use Diffusion Monte Carlo with Fixed Node approximation in order to calculate the energy per particle and the opposite-spin ... More
Non Standard Finite Difference Scheme for Mutualistic Interaction DescriptionJan 02 2012Jan 02 2015One of the more interesting themes of the mathematical ecology is the description of the mutualistic interaction between two interacting species. Based on continuous-time model developed by Holland and DeAngelis 2009 for consumer-resource mutualism description, ... More
Searching optimal shape in viscous flow: its dependence on Reynolds numberOct 09 2008In this work a simple problem on 2D optimal shape for body immersed in a viscous flow is analyzed. The body has geometrical constraints and its profile would be found in the class of cubics which satisfy those conditions. The optimal profile depends on ... More
On local symbolic approximation and resolution of ODEs using Implicit Function TheoremFeb 07 2006In this work the implicit function theorem is used for searching local symbolic resolution of differential equations. General results of existence for first order equations are proven and some examples, one relative to cavitation in a fluid, are developed. ... More
On the notion of laminar and weakly turbulent elementary fluid flows: a simple mathematical modelAug 28 2006An elementary analytical fluid flow is composed by a geometric domain, a list of analytical constraints and by the function which depends on the physical properties, as Reynolds number, of the considered fluid. For this object, notions of laminar or weakly ... More
The Time Dependent CP Violation in CharmApr 10 2012Apr 12 2012A model which describes the time-dependent CP formalism in $D^0$ decays has recently been proposed. There it has been highlighted a possible measurement of the angle $\beta_c$, in the charm unitarity triangle, using the decays $D^0\to K^+ K^-$ and $D^0\to ... More
Conglomerability and Finitely Additive RepresentationsAug 23 2015We prove results concerning the representation of a given distribution by means of a given random quantity. The existence of a solution to this problem is related to the notion of conglomerability, originally introduced by Dubins to study finitely additive ... More
Non Parametric Estimates of Option Prices Using SuperhedgingFeb 13 2015We propose a new non parametric technique to estimate the CALL function based on the superhedging principle. Our approach does not require absence of arbitrage and easily accommodates bid/ask spreads and other market imperfections. We prove some optimal ... More
The influence of Coulomb Correlations and Spin-Orbit Coupling in the electronic structure of double perovskites Sr$_2$XOsO$_6$ (X$=$Sc, Mg)Nov 20 2016We investigate the antiferromagnetic insulating state of the recently discovered double perovskites Sr$_2$XOsO$_6$ (X$=$Sc, Mg) by using ab-initio calculations (based on Density Functional Theory and Dynamical Mean-Field Theory) to elucidate the interplay ... More
On the invariance of the relative rest in doubly special relativityApr 03 2013In the framework of the most-studied doubly special relativity models the use of the naive formula $v=dE/dp$ has been argued to lead to inconsistencies connected to different rules of transformation, under boosts, of particles with the same energy but ... More
On the Ornstein-Uhlenbeck operator in convex sets of Banach spacesMar 10 2015Jun 22 2016We study the Ornstein-Uhlenbeck operator and the Ornstein-Uhlenbeck semigroup in an open convex subset of an infinite dimensional separable Banach space $X$. This is done by finite dimensional approximation. In particular we prove Logarithmic-Sobolev ... More
Modeling and ecodesigning crossflow ventilation fans with MathematicaJul 30 2010The efficiency of a simple model of crossflow fan is maximized when the geometry depends on a design parameter. The flow field is numerically computed using a Galerkin method for solving a Poisson partial differential equation.
Detecting quantum gravity in the skySep 22 2017Oct 20 2017Getting signatures of quantum gravity is one of the topical lines of research in modern theoretical physics and cosmology. This short review faces this challenge under a novel perspective. Instead of separating quantum-gravity effects of a specific model ... More
Relativistic particle in multiscale spacetimesJun 25 2013Sep 04 2013We study the action and the dynamics of a relativistic particle, uncharged or charged, in multiscale spacetimes. Invariance under reparametrizations and Poincar\'e symmetries uniquely determine the action and the line element to be the usual ones, without ... More
Observational effects from quantum cosmologySep 03 2012Oct 07 2013The status of quantum cosmologies as testable models of the early universe is assessed in the context of inflation. While traditional Wheeler-DeWitt quantization is unable to produce sizable effects in the cosmic microwave background, the more recent ... More
Towards multifractional calculusJan 01 2018Jun 21 2018After motivating the need of a multiscale version of fractional calculus in quantum gravity, we review current proposals and the program to be carried out in order to reach a viable definition of scale-dependent fractional operators. We present different ... More
Introduction to multifractional spacetimesSep 05 2012Oct 09 2012We informally review the construction of spacetime geometries with multifractal and, more generally, multiscale properties. Based on fractional calculus, these continuous spacetimes have their dimension changing with the scale; they display discrete symmetries ... More
Diffusion in quantum geometryApr 11 2012Aug 15 2012The change of the effective dimension of spacetime with the probed scale is a universal phenomenon shared by independent models of quantum gravity. Using tools of probability theory and multifractal geometry, we show how dimensional flow is controlled ... More
Gravity on a multifractalDec 06 2010Feb 09 2011Despite their diversity, many of the most prominent candidate theories of quantum gravity share the property to be effectively lower-dimensional at small scales. In particular, dimension two plays a fundamental role in the finiteness of these models of ... More
Cosmology of the Lifshitz universeApr 06 2009Sep 28 2009We study the ultraviolet complete non-relativistic theory recently proposed by Horava. After introducing a Lifshitz scalar for a general background, we analyze the cosmology of the model in Lorentzian and Euclidean signature. Vacuum solutions are found ... More
Multifractional theories: an unconventional reviewDec 16 2016Mar 28 2017We answer to 72 frequently asked questions about theories of multifractional spacetimes. Apart from reviewing and reorganizing what we already know about such theories, we discuss the physical meaning and consequences of the very recent flow-equation ... More
A Universal Homogeneous Simple Matroid of Rank $3$Jul 17 2017Oct 03 2018We construct a $\wedge$-homogeneous universal simple matroid of rank $3$, i.e. a countable simple rank~$3$ matroid $M_*$ which $\wedge$-embeds every finite simple rank $3$ matroid, and such that every isomorphism between finite $\wedge$-subgeometries ... More
A Version of Komlós Theorem for Additive Set FunctionsOct 11 2015Nov 27 2015We provide a version of the celebrated theorem of Koml\'os in which, rather then random quantities, a sequence of finitely additive measures is considered. We obtain a form of the subsequence principle and some applications.
Outer crust of a cold non-accreting magnetarMay 27 2015Sep 11 2015The outer crust structure and composition of a cold, non-accreting magnetar is studied. We model the outer crust to be made of fully equilibrated matter where ionized nuclei form a Coulomb crystal embedded in an electron gas. The main effects of the strong ... More
The geometry of learningMay 02 2016We establish a correspondence between classical conditioning processes and fractals. The association strength at a given training trial corresponds to a point in a disconnected set at a given iteration level. In this way, one can represent a training ... More
OPE Coefficients of the 3D Ising model with a trapping potentialNov 09 2015Apr 27 2016Recently the OPE coefficients of the 3D Ising model universality class have been calculated by studying the two-point functions perturbed from the critical point with a relevant field. We show that this method can be applied also when the perturbation ... More
Outliers Emphasis on Cluster Analysis - The use of squared Euclidean distance and fuzzy clustering to detect outliers in a datasetMar 21 2014Outlier is the term that indicates in statistics an anomalous observation, aberrant, clearly distant from others collected observations. The outliers are the subject to animated discussions in various contexts with regard to be or not to be considered ... More
Numerical resolution of some BVP using Bernstein polynomialsOct 18 2005In this work we present a method, based on the use of Bernstein polynomials, for the numerical resolution of some boundary values problems. The computations have not need of particular approximations of derivatives, such as finite differences, or particular ... More
Using virtual processors for SPMD parallel programsDec 21 2003In this paper I describe some results on the use of virtual processors technology for parallelize some SPMD computational programs. The tested technology is the INTEL Hyper Threading on real processors, and the programs are MATLAB scripts for floating ... More
A first approach for a possible cellular automaton model of fluids dynamicsMar 06 2003In this paper I present a first attempt for a possible description of fluids dynamics by mean of a cellular automata technique. With the use of simple and elementary rules, based on random behaviour either, the model permits to obtain the evolution in ... More
Costruction of classic exact solutions for Tricomi equationOct 08 2010A formula to construct classic exact solutions to Tricomi partial differential equation. The steps to obtain this formula require only elementary resolution of a simple system of first order PDEs.
Measures on SemilatticesJun 11 2010Jun 19 2012Every vector-valued, semimodular set function on a semilattice of sets extends uniquely to an additive set function on the generated ring.
Escaping from controversies in $CP$ violation measurements in charm decaysNov 12 2013The breaking of the $CP$ symmetry in $D^0$ meson decays has been awaited for a long time. After a set of measurements provided by the LHCb, CDF, and Belle Collaborations leading in march 2012 to combined results that were consistent with no $CP$ violation ... More
Wave Propagation and IR/UV Mixing in Noncommutative SpacetimesDec 31 2003In this thesis I study various aspects of theories in the two most studied examples of noncommutative spacetimes: canonical spacetime ($[x_{\mu},x_{\nu}]=\theta_{\mu\nu}$) and $\kappa$-Minkowski spacetime ($[x_{i},t]=\kappa^{-1} x_{i}$). In the first ... More
Deriving identities for Wigner {nj}-symbolsOct 26 2011Nov 30 2012We show how a simple and elegant graphical notation can be used to derive the Biedenharn-Elliot identity for the 6j-symbol and we demonstrate how the same technique can be applied to obtain new identities for the 6j. We then employ the same method also ... More
Distances on the moduli space of complex projective structuresDec 03 2018Let $S$ be a closed and oriented surface of genus $g$ at least $2$. In this (mostly expository) article, the object of study is the space $\mathcal{P}(S)$ of marked isomorphism classes of projective structures on $S$. We show that $\mathcal{P}(S)$, endowed ... More
Integrability of Newton ovals, computation of air damper inletsOct 13 2011About global and local algebraic integrability of ovals. A contribution to clarify Newton results and relative comments on his work done by Arnol'd and Pourciau. A possibile application to air damper sections computation is offered, as example of unexpected ... More
Loop quantum cosmology from group field theoryJul 30 2014Sep 27 2014We show that the effective dynamics of the recently proposed isotropic condensate state of group field theory with Laplacian kinetic operator can be equivalent to that of homogeneous and isotropic loop quantum cosmology in the improved dynamics quantization ... More
Slow-roll parameters in braneworld cosmologiesFeb 11 2004Apr 22 2004We present a general slow-roll formalism within braneworld-motivated cosmologies with non-standard effective Friedmann equations. Full towers of parameters involving either the inflaton potential or the Hubble parameter are constructed and the dynamics ... More
Multifractional spacetimes, asymptotic safety and Hořava-Lifshitz gravitySep 19 2012Jul 30 2013We compare the recently formulated multifractional spacetimes with field theories of quantum gravity based on the renormalization group (RG), such as asymptotic safety and Ho\v{r}ava--Lifshitz gravity. The change of spacetime dimensionality with the probed ... More
Regularized dualities in patch cosmologyOct 21 2004Following past investigations, we explore the symmetries of the Hamilton-Jacobi cosmological equations in the generalized patch formalism describing braneworld and tachyon scenarios. Dualities between different patches are established and regular dual ... More
Patch cosmology and noncommutative braneworldsOct 01 2004Nov 20 2004We review extra-dimensional and 4D cosmological scenarios through the effective Friedmann evolution on a brane. Some features involving noncommutative geometry and scalar/tachyon slow-roll inflation are considered.
Supermartingale Deomposition with General Index SetDec 09 2008Jan 21 2009We prove results on the existence of Dol\'{e}ans-Dade measures and of the Doob-Meyer decomposition for supermartingales indexed by a general index set
Bayesian models for cost-effectiveness analysis in the presence of structural zero costsJul 19 2013Bayesian modelling for cost-effectiveness data has received much attention in both the health economics and the statistical literature in recent years. Cost-effectiveness data are characterised by a relatively complex structure of relationships linking ... More
Triviality of Bloch and Bloch-Dirac bundlesJan 18 2006In the framework of the theory of an electron in a periodic potential, we reconsider the longstanding problem of the existence of smooth and periodic quasi-Bloch functions, which is shown to be equivalent to the triviality of the Bloch bundle. By exploiting ... More
Conglomerability and Finitely Additive RepresentationsAug 23 2015Mar 31 2017We prove results concerning the representation of a given distribution by means of a given random quantity. The existence of a solution to this problem is related to the notion of conglomerability, originally introduced by Dubins to study finitely additive ... More
A New $ω$-Stable PlaneSep 20 2017Apr 19 2019We use a variation on Mason's $\alpha$-function as a pre-dimension function to construct a not one-based $\omega$-stable plane $P$ (i.e. a simple rank $3$ matroid) which does not admit an algebraic representation (in the sense of matroid theory) over ... More
The Joint Projected and Skew NormalDec 01 2015Jun 26 2016We introduce a new multivariate circular linear distribution suitable for modeling direction and speed in (multiple) animal movement data. To properly account for specific data features, such as heterogeneity and time dependence, a hidden Markov model ... More
A New $ω$-Stable PlaneSep 20 2017Feb 10 2019We use a variation on Mason's $\alpha$-function as a pre-dimension function to construct a not one-based $\omega$-stable plane $P$ (i.e. a simple rank $3$ matroid) which does not admit an algebraic representation (in the sense of matroid theory) over ... More
Finitely Additive SupermartingalesJan 08 2008Apr 21 2008The concept of finitely additive supermartingales, originally due to Bochner, is revived and developed. We exploit it to study measure decompositions over filtered probability spaces and the properties of the associated Dol\'{e}ans-Dade measure. We obtain ... More
Inflationary spectra and observations in loop quantum cosmologyOct 03 2011May 22 2012We review some recent progress in the extraction of inflationary observables in loop quantum cosmology. Inverse-volume quantum corrections induce a growth of power in the large-scale cosmological spectra and are constrained by observations.
Fractal universe and quantum gravityDec 16 2009Jun 24 2010We propose a field theory which lives in fractal spacetime and is argued to be Lorentz invariant, power-counting renormalizable, ultraviolet finite, and causal. The system flows from an ultraviolet fixed point, where spacetime has Hausdorff dimension ... More
Braneworld cosmology and noncommutative inflationMar 04 2005Mar 24 2005In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to depend on some ... More
Non-Gaussianity in braneworld and tachyon inflationNov 29 2004Oct 19 2005We calculate the bispectrum of single-field braneworld inflation, triggered by either an ordinary scalar field or a cosmological tachyon, by means of a gradient expansion of large-scale non-linear perturbations coupled to stochastic dynamics. The resulting ... More
Patch dualities and remarks on nonstandard cosmologiesOct 06 2004Dec 31 2004In this paper we establish dualities between inflationary, cyclic/ekpyrotic, and phantom cosmologies within the patch formalism approximating high-energy effects in scenarios with extra dimensions. The exact dualities relating the four-dimensional spectra ... More
Consistency equations in Randall-Sundrum cosmology: a test for braneworld inflationOct 27 2003Apr 05 2004In the context of an inflationary Randall-Sundrum Type II braneworld (RS2) we calculate spectral indices and amplitudes of cosmological scalar and tensor perturbations, up to second order in slow-roll parameters. Under very simple assumptions, extrapolating ... More
Multifractional spacetimes from the Standard Model to cosmologySep 22 2017Oct 29 2018We review recent theoretical progress and observational constraints on multifractional spacetimes, geometries that change with the probed scale. On the theoretical side, the basic structure of the Standard Model and of the gravitational action is discussed. ... More
Geometry and field theory in multi-fractional spacetimeJul 25 2011Jan 18 2012We construct a theory of fields living on continuous geometries with fractional Hausdorff and spectral dimensions, focussing on a flat background analogous to Minkowski spacetime. After reviewing the properties of fractional spaces with fixed dimension, ... More
Noncommutative models in patch cosmologyJun 01 2004Nov 20 2004We consider several classes of noncommutative inflationary models within an extended version of patch cosmological braneworlds, starting from a maximally invariant generalization of the action for scalar and tensor perturbations to a noncommutative brane ... More
Degeneracy of consistency equations in braneworld inflationDec 17 2003Jun 02 2004In a Randall-Sundrum type II inflationary scenario we compute perturbation amplitudes and spectral indices up to next-to-lowest order in the slow-roll parameters, starting from the well-known lowest-order result for a de Sitter brane. Using two different ... More
Independence Logic and Abstract Independence RelationsJan 27 2014Sep 08 2016We continue the work on the relations between independence logic and the model-theoretic analysis of independence, generalizing the results of [15] and [16] to the framework of abstract independence relations for an arbitrary AEC. We give a model-theoretic ... More
Geometrization of purely hyperbolic representations in $\text{PSL}_2\Bbb R$Dec 10 2017May 24 2019Let $S$ be a surface of genus $g$ at least $2$. A representation $\rho:\pi_1S\longrightarrow \text{PSL}_2\Bbb R$ is said to be purely hyperbolic if its image consists only of hyperbolic elements other than the identity. We may wonder under which conditions ... More
A result of existence and uniqueness for a cavity driven flow. Analytical expression of the solutionDec 22 2009In this work a result of existence and uniqueness for a plane cavity driven steady flow is deduced using an analytical method for the resolution of a linear partial differential problem on a triangular domain. The solution admits a symbolic expression ... More
Maximal $L^2$ regularity for Ornstein-Uhlenbeck equation in convex sets of Banach spacesOct 22 2015We study the elliptic equation $\lambda u-L^{\Omega}u=f$ in an open convex subset $\Omega$ of an infinite dimensional separable Banach space $X$ endowed with a centered non-degenerate Gaussian measure $\gamma$, where $L^\Omega$ is the Ornstein-Uhlenbeck ... More
Exact solution of a differential problem in analytical fluid dynamics: use of Airy's functionsJun 28 2006Treating a boundary value problem in analytical fluid dynamics, translation of 2D steady Navier-Stokes equations to ordinary differential form leads to a second order equation of Riccati type. In the case of a compressible fluid with constant kinematic ... More
Aphids, Ants and Ladybirds: a mathematical model predicting their population dynamicsMay 13 2019The interaction between aphids, ants and ladybirds has been investigated from an ecological point of view since many decades, while there are no attempts to describe it from a mathematical point of view. This paper introduces a new mathematical model ... More
On the Ornstein-Uhlenbeck operator in convex sets of Banach spacesMar 10 2015Sep 11 2017We study the Ornstein-Uhlenbeck operator and the Ornstein-Uhlenbeck semigroup in an open convex subset of an infinite dimensional separable Banach space $X$. This is done by finite dimensional approximation. In particular we prove Logarithmic-Sobolev ... More
Subvarieties of general type on a general projective hypersurfaceApr 24 2002Nov 04 2002We study subvarieties of a general projective degree $d$ hypersurface $X_d\subset \mathbf P^n$. Our main theorem, which improves previous results of L. Ein and C. Voisin, implies in particular the following sharp corollary: any subvariety of a general ... More
Searching the (really) real general solution of 2D Laplace differential equationOct 01 2009This is not a new result. Purpose of this work is to describe a method to search the analytical expression of the general real solution of the two-dimensional Laplace differential equation. This thing is not easy to find in scientific literature and, ... More
Undeformed (additive) energy conservation law in Doubly Special RelativityJul 25 2007Nov 11 2008All the Doubly Special Relativity (DSR) models studied in literature so far involve a deformation of the energy conservation rule that forces us to release the hypothesis of the additivity of the energy for composite systems. In view of the importance ... More
Bound states in ab initio approaches to quantum transport: A time-dependent formulationAug 17 2006May 20 2007In this work we study the role of bound electrons in quantum transport. The partition-free approach by Cini is combined with time-dependent density functional theory (TDDFT) to calculate total currents and densities in interacting systems. We show that ... More
A Finite Axiomatization of G-DependenceDec 15 2015Sep 08 2016We show that a form of dependence known as G-dependence (originally introduced by Kurt Grelling) admits a very natural finite axiomatization. We also prove that G-dependence admits Armstrong relations.
Graviton scattering amplitudes and Pure Connection Formulation of GRJun 17 2013We show how the recently introduced "Pure Connection Formulation" of gravity provides a natural framework for approaching the problem of computing graviton scattering amplitudes. In particular, we show that the interaction vertices are greatly simplified ... More
Multiscale spacetimes from first principlesSep 08 2016We formulate a theorem for the general profile of the Hausdorff and the spectral dimension of multiscale geometries, assuming a smooth and slow change of spacetime dimensionality at large scales. Agreement with various scenarios of quantum gravity is ... More
Lorentz violations in multifractal spacetimesMar 09 2016Using the recent observation of gravitational waves (GW) produced by a black-hole merger, we place a lower bound on the energy above which a multifractal spacetime would manifest an anomalous geometry and, in particular, violations of Lorentz invariance. ... More
First results from the NA60 experiment at CERNJul 30 2003Since 1986, several heavy ion experiments have studied some signatures of the formation of the quark-gluon plasma and a few exciting results have been found. However, some important questions are still unanswered and require new measurements. The NA60 ... More
Deriving the Regge-Wheeler and Zerilli equations in the general static spherically-symmetric case with Mathematica and MathTensorNov 25 1999An efficient approach to tensor perturbation calculations by proper use of computer algebra methods is described, reaching the sufficient generality required for a comprehensive analysis of the Schwarzschild and Reissner-Nordstroem metric stability.
Dijet Rapidity Gaps in Photoproduction from Perturbative QCDMar 03 1999By defining dijet rapidity gap events according to interjet energy flow, we treat the photoproduction cross section of two high transverse momentum jets with a large intermediate rapidity region as a factorizable quantity in perturbative QCD. We show ... More
Computational Aspects of a Numerical Model for Combustion FlowNov 02 2004A computational method for numeric resolution of a PDEs system, based on a Finite Differences schema integrated by interpolations of partial results, and an estimate of the error of its solution respect to the normal FD solution.
A generalization of Amdahl's law and relative conditions of parallelismSep 25 2002In this work I present a generalization of Amdahl's law on the limits of a parallel implementation with many processors. In particular I establish some mathematical relations involving the number of processors and the dimension of the treated problem, ... More
Using matrices in post-processing phase of CFD simulationsApr 22 2004In this work I present a technique of construction and fast evaluation of a family of cubic polynomials for analytic smoothing and graphical rendering of particles trajectories for flows in a generic geometry. The principal result of the work was implementation ... More
Poster on MPI application in Computational Fluid DynamicsOct 06 2003Poster-presentation of the paper "Message Passing Fluids: molecules as processes in parallel computational fluids" held at "EURO PVMMPI 2003" Congress; the paper is on the proceedings "Recent Advances in Parallel Virtual Machine and Message Passing Interface", ... More
Option Pricing in an Imperfect WorldJun 02 2014Sep 09 2016In a model with no given probability measure, we consider asset pricing in the presence of frictions and other imperfections and characterize the property of coherent pricing, a notion related to (but much weaker than) the no arbitrage property. We show ... More
The Theorem of Halmos and Savage under Finite AdditivityJan 30 2014Given a generalization of Lebesgue decomposition we obtain an extension to the finitely additive setting of the theorems of Halmos and Savage and of Yan.