Results for "Francesca Greselin"

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Maximum likelihood estimation in constrained parameter spaces for mixtures of factor analyzersJan 08 2013Mixtures of factor analyzers are becoming more and more popular in the area of model based clustering of high-dimensional data. According to the likelihood approach in data modeling, it is well known that the unconstrained log-likelihood function may ... More
Measuring economic inequality and risk: a unifying approach based on personal gambles, societal preferences and referencesAug 01 2015The underlying idea behind the construction of indices of economic inequality is based on measuring deviations of various portions of low incomes from certain references or benchmarks, that could be point measures like population mean or median, or curves ... More
Inferential results for a new measure of inequalityJun 17 2017In this paper we derive inferential results for a new index of inequality, specifically defined for capturing significant changes observed both in the left and in the right tail of the income distributions. The latter shifts are an apparent fact for many ... More
A robust approach to model-based classification based on trimming and constraintsApr 12 2019In a standard classification framework a set of trustworthy learning data are employed to build a decision rule, with the final aim of classifying unlabelled units belonging to the test set. Therefore, unreliable labelled observations, namely outliers ... More
Can three-neutron forces be constrained by empirical information on the neutron skin of 48Ca and 208Pb?Jun 12 2016We calculate the neutron matter equation of state from two-neutron forces up to fifth order of the chiral expansion and investigate the order-by-order convergence of the predictions. Based on these equations of state, we derive the binding energies and ... More
On Squares in Lucas SequencesSep 02 2013In this short paper, we prove, by only using elementary tools, general cases when $U_n(P,Q) \neq \square$, where $U_n(P,Q)$ is the Lucas sequence of the first type.
Sphere systems, standard form, and cores of products of treesOct 26 2016We introduce the concept of a standard form for two embedded maximal sphere systems in the doubled handlebody, and we prove an existence and uniqueness result. In particular, we show that pairs of maximal sphere systems in the doubled handlebody (up to ... More
On the spectrum of the Laplace-Beltrami operator for $p$-forms for a class of warped product metricsNov 12 2003We explicitely compute the essential spectrum of the Laplace-Beltrami operator for $p$-forms for the class of warped product metrics $d\sigma^2= y^{2a}dy^2 + y^{2b}d\theta_{\partial M}^2$, where $y$ is a boundary defining function on a compact manifold ... More
Supergravity models of Quintessence and Supersymmetry breakingDec 15 2000The issue of Supersymmetry breaking in the context of Supergravity models of Quintessence is discussed.
Symmetries of quadratic forms classes and of quadratic surds continued fractions. Part II: Classification of the periods' palindromesAug 15 2007Mar 27 2008The continue fractions of quadratic surds are periodic, according to a theorem by Lagrange. Their periods may have differing types of symmetries. This work relates these types of symmetries to the symmetries of the classes of the corresponding indefinite ... More
Stationary layered solutions for a system of Allen-Cahn type equationsNov 25 2012Dec 03 2012We consider a class of semilinear elliptic system of the form $-\Delta u(x,y)+\nabla W(u(x,y))=0,\quad (x,y)\in\R^{2}$ where $W:\R^{2}\to\R$ is a double well non negative symmetric potential. We show, via variational methods, that if the set of solutions ... More
Matricial formulae for partitionsJun 07 2008The exponential of the triangular matrix whose entries in the diagonal at distance $n$ from the principal diagonal are all equal to the sum of the inverse of the divisors of $n$ is the triangular matrix whose entries in the diagonal at distance $n$ from ... More
Periodic configurations of subshifts on groupsFeb 14 2014We study the density of periodic configurations for shift spaces defined on (the Cayley graph of) a finitely generated group. We prove that in the case of a full shift on a residually finite group and in that of a group shift space on an abelian group, ... More
Atomism and Relationalism as guiding principles for Quantum GravitySep 05 2013The research in quantum gravity has jauntily grown in the recent years, intersecting with conceptual and philosophical issues that have a long history. In this paper I analyze the conceptual basis on which Loop Quantum Gravity has grown, the way it deals ... More
Dark Energy and the Dark Matter relic abundanceSep 22 2004Two mechanisms by which the Quintessence scalar could enhance the relic abundance of dark matter particles are discussed. This effect can have an impact on supersymmetric candidates for dark matter.
Can the Inflaton and the Quintessence scalar be the same field?Feb 08 2000The most recent cosmological data point in the direction of a cosmological constant dominated universe. A suitable candidate for providing the required acceleration is a rolling scalar field named ``quintessence''. We address the issue of building a particle ... More
An application of scattering theory to the spectrum of the Laplace-Beltrami operatorJan 10 2003Applying a theorem due to Belopol'ski and Birman, we show that the Laplace-Beltrami operator on 1-forms on ${\bf R}^n$ endowed with an asymptotically Euclidean metric has absolutely continuous spectrum equal to $[0, +\infty)$.
Scattering theory for p-forms on hyperbolic real spaceJan 25 2001Due to spectral obstructions, a scattering theory in the Lax-Phillips sense for the wave equation for differential p-forms on H^{n+1} cannot be developed. As a consequence, Huygens' principle for the wave equation in this context does not hold. If we ... More
The range of all regularities for polynomial ideals with a given Hilbert functionJan 30 2019Given the Hilbert function $u$ of a closed subscheme of a projective space over an infinite field $K$, let $m_u$ and $M_u$ be, respectively, the minimum and the maximum among all the Castelnuovo-Mumford regularities of schemes with Hilbert function $u$. ... More
An invariant of colored links via skein relationAug 28 2015Dec 02 2015In this note we define a polynomial invariant for colored links by a skein relation. It specializes to the Jones polynomial for classical links.
Some necessary and some sufficient conditions for the compactness of the embedding of weighted Sobolev spacesJan 30 2003We give some necessary conditions and sufficient conditions for the compactness of the embedding of Sobolev spaces $W^{1,p}(\Omega,w) \to L^p(\Omega,w),$ where $w$ is some weight on a domain $\Omega \subset \Real^n$.
Projective geometry from Poisson algebrasDec 08 2009Dec 09 2010In analogy with the Poisson algebra of the quadratic forms on the symplectic plane, and the notion of duality in the projective plane introduced by Arnold in \cite{Arn}, where the concurrence of the triangle altitudes is deduced from the Jacobi identity, ... More
Macroscopic limit of a bipartite Curie-Weiss model: a dynamical approachJun 16 2014Aug 25 2014We analyze the Glauber dynamics for a bi-populated Curie-Weiss model. We obtain the limiting behavior of the empirical averages in the limit of infinitely many particles. We then characterize the phase space of the model in absence of magnetic field and ... More
Supersymmetric QuintessenceJun 18 1999Recent data point in the direction of a cosmological constant dominated universe. We investigate the role of supersymmetric QCD with N_f < N_c as a possible candidate for dynamical cosmological constant (``quintessence''). We take in full consideration ... More
Gysin exact sequences for quantum weighted lens spacesOct 04 2016We describe quantum weighted lens spaces as total spaces of quantum principal circle bundles, using a Cuntz-Pimsner model. The corresponding Pimsner exact sequence is interpreted as a noncommutative analogue of the Gysin exact sequence. We use the sequence ... More
Cesaro averages of Euler-like functionsJun 08 2008By Euler-like function we mean a function defined on the positive integers and associating to $n$ the product, over all primes $p$ dividing $n$, of 1 plus (or minus) the inverse of $p$ to the power $s$. We calculate the limit of the Cesaro mean of these ... More
Quadratic Chabauty for (bi)elliptic curves and Kim's conjectureApr 09 2019We explore a number of problems related to the quadratic Chabauty method for determining integral points on hyperbolic curves. We remove the assumption of semistability in the description of the quadratic Chabauty sets $\mathcal{X}(\mathbb{Z}_p)_2$ containing ... More
Theta functions on the moduli space of parabolic bundlesFeb 18 2003Let X be a smooth projective connected curve of genus $g \ge 2$ and let I be a finite set of points of X. Fix a parabolic structure on I for rank r vector bundles on X. Let $M^{par}$ denote the moduli space of parabolic semistable bundles and let $L^{par}$ ... More
Infinities as a measure of our ignoranceMay 10 2013The quantization of gravity offers a solution to the presence of singularities in cosmology. Infinities are removed because of the existence of finite quanta of spacetime. This is one of the most important prediction of Loop Quantum Gravity. But treating ... More
General covariant transition amplitudes in quantum cosmologyOct 13 2011The path-integral approach to cosmology consists in the computation of transition amplitudes between states of the quantum geometry of the universe. In the past, the concrete computation of these transitions amplitudes has been performed in a perturbative ... More
Spinfoam Cosmology: quantum cosmology from the full theoryNov 21 2010Quantum cosmology is usually studied quantizing symmetry-reduced variables. Is it possible, instead, to define quantum cosmology starting from the full quantum gravity theory? In Loop Quantum Gravity (LQG), it is possible to cut the degrees of freedom ... More
Consequences of the functional equation of the $p$-adic $L$-function of an elliptic curveNov 09 2016We prove that the first two coefficients in the series expansion around $s=1$ of the $p$-adic $L$-function of an elliptic curve over $\mathbb{Q}$ are related by a formula involving the conductor of the curve. This is analogous to a recent result of Wuthrich ... More
Quintessence, Supersymmetry and InflationAug 31 1999Recent data point in the direction of a $\Lambda$ dominated universe. We briefly review ``Quintessence'' as a model for a dynamical cosmological term and analyse the role of Susy QCD as a possible particle physics candidate. The multiscalar content of ... More
Performance of the ALICE Time-Of-Flight detector at the LHCJun 11 2018The ALICE Time-Of-Flight (TOF) detector at LHC is based on the Multigap Resistive Plate Chambers (MRPCs). The TOF performance during LHC Run 2 is here reported. Particular attention is given to the improved time resolution reached by TOF detector of $56$ ... More
On the topology of surfaces with the generalised simple lift propertyDec 14 2016In this paper, we study the geometry of surfaces with the generalised simple lift property. This work generalises previous results by Bernstein and Tinaglia, and it is motivated by the fact that leaves of a minimal lamination obtained as a limit of a ... More
Symmetries of quadratic forms classes and of quadratic surds continued fractions. Part I: A Poincaré model for the de Sitter worldAug 11 2007Mar 27 2008The problem of the classification of the indefinite binary quadratic forms with integer coefficients is solved introducing a special partition of the de Sitter world, where the coefficients of the forms lie, into separate domains. Every class of indefinite ... More
A pilot study on the daily control capability of s-EMG prosthetic hands by amputeesNov 18 2015Nov 24 2015Surface electromyography is a valid tool to gather muscular contraction signals from intact and amputated subjects. Electromyographic signals can be used to control prosthetic devices in a noninvasive way distinguishing the movements performed by the ... More
Separation of branches of O(N-1)-invariant solutions for a semilinear elliptic equationFeb 17 2016We consider a semilinear elliptic problem in an annulus of R^N, with N>1. Recent results ensure that there exists a sequence p_k of exponents of the nonlinear term at which a nonradial bifurcation from the radial solution occurs. Exploiting the properties ... More
Many-nodes/many-links spinfoam: the homogeneous and isotropic caseJul 13 2011Oct 13 2011I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular graphs, with an arbitrary number of links and nodes, and coherent states peaked on a homogeneous and isotropic geometry. This form of the amplitude can be applied for example to ... More
Relational Quantum CosmologyAug 22 2015The application of quantum theory to cosmology raises a number of conceptual questions, such as the role of the quantum-mechanical notion of "observer" or the absence of a time variable in the Wheeler-DeWitt equation. I point out that a relational formulation ... More
Quintessence and the dark matter abundanceSep 11 2003Results of a recent study on how the Quintessence scalar could affect the relic abundance of dark matter particles are presented.
On the spectrum of the Laplace-Beltrami operator for p-forms on asymptotically hyperbolic manifoldsNov 07 2003Under suitable conditions on the asymptotic decay of the metric, we compute the essential spectrum of the Laplace-Beltrami operator acting on $p$-forms on asymptotically hyperbolic manifolds.
New invariants of links from a skein invariant of colored linksDec 02 2015Dec 10 2015New invariants of links are constructed using the skein invariant polynomial of colored links defined by the author in [1]. These invariants are stronger than the homflypt polynomial.
Bell-shaped nonstationary refinable rippletsJan 15 2015We study the approximation properties of the class of nonstationary refinable ripplets introduced in \cite{GP08}. These functions are solution of an infinite set of nonstationary refinable equations and are defined through sequences of scaling masks that ... More
Intrinsic Regular Surfaces of low co-dimension in Heisenberg groupsMar 11 2019In this paper we study intrinsic regular submanifolds of $\mathbb{H}^n$, of low co-dimension in relation with the regularity of their intrinsic parametrization. We extend some results proved for one co-dimensional $\mathbb{H}$-regular surfaces, characterizing ... More
Rational tangles and the modular groupAug 15 2009There is a natural way to associate with a transformation of an isotopy class of rational tangles to another, an element of the modular group. The correspondence between the isotopy classes of rational tangles and rational numbers follows, as well as ... More
A $p$-Laplacian Neumann problem with a possibly supercritical nonlinearityOct 15 2016We look for nonconstant, positive, radially nondecreasing solutions of the quasilinear equation $-\Delta_p u+u^{p-1}=f(u)$ with $p>2$, in the unit ball $B$ of $\mathbb R^N$, subject to homogeneous Neumann boundary conditions. The assumptions on the nonlinearity ... More
A monotonicity result under symmetry and Morse index constraints in the planeApr 08 2019This paper deals with solutions of semilinear elliptic equations of the type \[ \left\{\begin{array}{ll} -\Delta u = f(|x|, u) \qquad & \text{ in } \Omega, \\ u= 0 & \text{ on } \partial \Omega, \end{array} \right. \] where $\Omega$ is a radially symmetric ... More
Learning Onto-Relational Rules with Inductive Logic ProgrammingOct 10 2012Oct 29 2012Rules complement and extend ontologies on the Semantic Web. We refer to these rules as onto-relational since they combine DL-based ontology languages and Knowledge Representation formalisms supporting the relational data model within the tradition of ... More
Robust Financial BubblesFeb 17 2016We study the concept of financial bubble in a market model endowed with a set of probability measures, typically mutually singular to each other. In this setting we introduce the notions of robust bubble and robust fundamental value in a consistent way ... More
The taxonomic distribution of asteroids from multi-filter all-sky photometric surveysJul 09 2013The distribution of asteroids across the Main Belt has been studied for decades to understand the compositional distribution and what that tells us about the formation and evolution of our solar system. All-sky surveys now provide orders of magnitude ... More
A note on the Guerra and Talagrand theorems for Mean Field Spin Glasses: the simple case of spherical modelsApr 01 2005Jul 20 2005The aim of this paper is to discuss the main ideas of the Talagrand proof of the Parisi Ansatz for the free-energy of Mean Field Spin Glasses with a physicist's approach. We consider the case of the spherical $p$-spin model, which has the following advantages: ... More
A p-Laplacian supercritical Neumann problemJun 21 2016For $p>2$, we consider the quasilinear equation $-\Delta_p u+|u|^{p-2}u=g(u)$ in the unit ball $B$ of $\mathbb R^N$, with homogeneous Neumann boundary conditions. The assumptions on $g$ are very mild and allow the nonlinearity to be possibly supercritical ... More
Flavor-dependent azimuthal modulations in unpolarized SIDIS cross section at HERMESNov 24 2010The $\cos\phi_h$ and $\cos2\phi_h$ azimuthal modulations of the unpolarized hadron Semi-Inclusive Deep Inelastic Scattering cross section are sensitive to the quark intrinsic transverse momentum and transverse spin. These modulations have been measured ... More
Updating and downdating techniques for optimizing network communicabilityOct 20 2014Aug 20 2015The total communicability of a network (or graph) is defined as the sum of the entries in the exponential of the adjacency matrix of the network, possibly normalized by the number of nodes. This quantity offers a good measure of how easily information ... More
ABA+: Assumption-Based Argumentation with PreferencesOct 10 2016Oct 12 2016We present ABA+, a new approach to handling preferences in a well known structured argumentation formalism, Assumption-Based Argumentation (ABA). In ABA+, preference information given over assumptions is incorporated directly into the attack relation, ... More
Unabsorbed Seyfert 2 galaxiesAug 28 2002We present a sample of 17 type 2 Seyfert galaxies which have an X-ray column density lower than 10^{22} cm^{-2}. The Compton thin nature of these sources is strongly suggested by isotropic indicators. We estimate the fraction of these sources to be in ... More
Consensus versus persistence of disagreement in opinion formation: the role of zealotsMar 08 2016We consider a general class of three--state models where individuals hold one of two opposite opinions, or are neutral, and exchange opinions in generic pairwise interactions. We show that when opinions spread in a population where a fraction of individuals ... More
Interplay between media and social influence in the collective behavior of opinion dynamicsNov 03 2015Messages conveyed by media act as a major drive in shaping attitudes and inducing opinion shift. On the other hand, individuals are strongly affected by peer pressure while forming their own judgment. We solve a general model of opinion dynamics where ... More
Stepping out of Homogeneity in Loop Quantum CosmologyMay 29 2008We explore the extension of quantum cosmology outside the homogeneous approximation, using the formalism of loop quantum gravity. We introduce a model where some of the inhomogeneous degrees of freedom are present, providing a tool for describing general ... More
Optimal multi-binding unification for sharing and linearity analysisJun 10 2013In the analysis of logic programs, abstract domains for detecting sharing properties are widely used. Recently the new domain $\Linp$ has been introduced to generalize both sharing and linearity information. This domain is endowed with an optimal abstract ... More
Low-Scale See-Saw Mechanisms for Light NeutrinosJul 03 2000Jun 27 2001Alternatives to the see-saw mechanism are explored in supersymmetric models with three right-handed or sterile neutrinos. Tree-level Yukawa couplings can be drastically suppressed in a natural way to give sub-eV Dirac neutrino masses. If, in addition, ... More
Modeling and Estimation of Discrete-Time Reciprocal Processes via Probabilistic Graphical ModelsMar 14 2016May 13 2016Reciprocal processes are acausal generalizations of Markov processes introduced by Bernstein in 1932. In the literature, a significant amount of attention has been focused on developing dynamical models for reciprocal processes. In this paper, we provide ... More
Perturbations in Quintessential InflationNov 24 1998Recently Peebles and Vilenkin proposed and quantitatively analyzed the fascinating idea that a substantial fraction of the present cosmic energy density could reside in the vacuum potential energy of the scalar field responsible for inflation (quintessential ... More
Interpretation of abundance ratiosSep 24 2004In this paper we discuss abundance ratios and their relation to stellar nucleosynthesis and other parameters of chemical evolution models, reviewing and clarifying the correct use of the observed abundance ratios in several astrophysical contests. In ... More
On the fundamental group of an abelian coverMay 20 1993We study the behaviour of the topological fundamental group under totally ramified abelian covers (a special case of abelian Galois covers) of complex projective varieties of dimension at least 2.
Justifying Answer Sets using ArgumentationNov 20 2014Dec 02 2014An answer set is a plain set of literals which has no further structure that would explain why certain literals are part of it and why others are not. We show how argumentation theory can help to explain why a literal is or is not contained in a given ... More
Large spin expansion of the long-range Baxter equation in the sl(2) sector of N=4 SYMOct 10 2007Jan 24 2008Recently, several multi-loop conjectures have been proposed for the spin dependence of anomalous dimensions of twist-2 and 3 operators in the sl(2) sector of N=4 SYM. Currently, these conjectures are not proven, although several consistency checks have ... More
Pre-big-bang black-hole remnants and the past low entropyMay 08 2018Nov 09 2018Dark matter could be composed by black-hole remnants formed before the big-bang era in a bouncing cosmology. This hypothetical scenario has major implications on the issue of the arrow of time: it would upset a common attribution of past low entropy to ... More
Small black/white hole stability and dark matterMay 10 2018Nov 09 2018We show that the expected lifetime of white holes formed as remnants of evaporated black holes is consistent with their production at reheating. We give a simple quantum description of these objects and argue that a quantum superposition of black and ... More
On the implementation of a finite volumes scheme with monotone transmission conditions for scalar conservation laws on a star-shaped networkFeb 06 2019In this paper we validate the implementation of the numerical scheme proposed in [3]. The validation is made by comparison with an explicit solution here obtained, and the solutions of Riemann problems for several networks. We then perform some simulations ... More
Symmetry and rigidity for the hinged composite plate problemMay 25 2018Oct 09 2018The composite plate problem is an eigenvalue optimization problem related to the fourth order operator $(-\Delta)^2$. In this paper we continue the study started in [10], focusing on symmetry and rigidity issues in the case of the hinged composite plate ... More
Poincaré-Bendixson theorems for meromorphic connections and homogeneous vector fieldsMar 20 2009Dec 16 2009We first study the dynamics of the geodesic flow of a meromorphic connection on a Riemann surface, and prove a Poincar\'e-Bendixson theorem describing recurrence properties and $\omega$-limit sets of geodesics for a meromorphic connection on $\P^1(\C)$. ... More
A characterization related to Schrödinger equations on Riemannian manifoldsApr 07 2017In this paper we consider the following problem $$\begin{cases} -\Delta_{g}u+V(x)u=\lambda\alpha(x)f(u), & \mbox{in }M\\ u\geq0, & \mbox{in }M\\ u\to0, & \mbox{as }d_{g}(x_{0},x)\to\infty \end{cases}$$where $(M,g)$ is a $N$-dimensional ($N\geq3)$, non-compact ... More
Significant Enhancement of Neutralino Dark Matter Annihilation from Electroweak BremsstrahlungAug 05 2013Feb 19 2014Indirect searches for the cosmological dark matter have become ever more competitive during the past years. Here, we report the first full calculation of leading electroweak corrections to the annihilation rate of supersymmetric neutralino dark matter. ... More
The Cuntz-Pimsner extension and mapping cone exact sequencesMay 27 2016For Cuntz-Pimsner algebras of bi-Hilbertian bimodules of finite Jones-Watatani index satisfying some side conditions, we give an explicit isomorphism between the $K$-theory exact sequences of the mapping cone of the inclusion of the coefficient algebra ... More
Infinitely many cyclic solutions to the Hamilton-Waterloo problem with odd length cyclesJan 28 2015Mar 31 2016It is conjectured that for every pair $(\ell,m)$ of odd integers greater than 2 with $m \equiv 1\; \pmod{\ell}$, there exists a cyclic two-factorization of $K_{\ell m}$ having exactly $(m-1)/2$ factors of type $\ell^m$ and all the others of type $m^{\ell}$. ... More
Tied LinksMar 02 2015Jun 03 2016In this paper we introduce the tied links, i.e. ordinary links provided with some ties between strands. The motivation for introducing such objects originates from a diagrammatical interpretation of the defining generators of the so-called algebra of ... More
Homological projective duality for linear systems with base locusNov 30 2015We show how blowing up varieties in base loci of linear systems gives a procedure for creating new homological projective duals from old. Starting with a HP dual pair $X,Y$ and smooth orthogonal linear sections $X_L,Y_L$, we prove that the blowup of $X$ ... More
Partial Regularity for Stationary Solutions to Liouville-Type Equation in dimension 3Feb 12 2008In dimension $n=3$, we prove that the singular set of any stationary solution to the Liouville equation $-\Delta u=e^u$, which belongs to $W^{1,2}$, has Hausdorff dimension at most 1.
Approximate controllability via adiabatic techniques for the three-inputs controlled Schr{ö}dinger equationFeb 24 2015We consider a system described by a controlled bilinear Schr{\"o}dinger equation with three external inputs. We provide a constructive method to approximately steer the system from a given energy level to a superposition of energy levels corresponding ... More
The Godunov Method for a 2-Phase ModelMar 15 2017We consider the Godunov numerical method to the phase-transition traffic model, proposed in [6], by Colombo, Marcellini, and Rascle. Numerical tests are shown to prove the validity of the method. Moreover we highlight the differences between such model ... More
Some Remarks on Pohozaev-Type IdentitiesNov 09 2018The aim of this note is to discuss in more detail the Pohozaev-type identities that have been recently obtained by the author, Paul Laurain and Tristan Rivi\`ere in the framework of half-harmonic maps defined either on $R$ or on the sphere $S^1$ with ... More
Predicting triadic closure in networks using communicability distance functionsNov 20 2014May 07 2015We propose a communication-driven mechanism for predicting triadic closure in complex networks. It is mathematically formulated on the basis of communicability distance functions that account for the quality of communication between nodes in the network. ... More
The effect of softening on dynamical simulations of galaxiesAug 30 2013Dynamical simulations are a fundamental tool for studying the secular evolution of disc galaxies. Even at their maximum resolution, they still follow a limited number of particles and typically resolve scales of the order of a few tens of parsecs. Generally, ... More
On the orbital and internal evolution of cluster galaxiesSep 04 2012Galaxies inhabiting a cluster environment experience significant evolution in their orbital motions throughout time; this is accompanied by changes in the anisotropy parameter, measuring the relative importance of radial and tangential motions for a given ... More
Adaptive gravitational softening in GADGETJul 14 2011Cosmological simulations of structure formation follow the collisionless evolution of dark matter starting from a nearly homogeneous field at early times down to the highly clustered configuration at redshift zero. The density field is sampled by a number ... More
Building Rules on Top of Ontologies for the Semantic Web with Inductive Logic ProgrammingNov 12 2007Building rules on top of ontologies is the ultimate goal of the logical layer of the Semantic Web. To this aim an ad-hoc mark-up language for this layer is currently under discussion. It is intended to follow the tradition of hybrid knowledge representation ... More
Current status of Dirac-Brueckner-Hartree-Fock calculations in asymmetric nuclear matterJun 11 2008We review the current status of our microscopic calculations in asymmetric nuclear matter. Updated predictions of the equation of state are made available to potential users. We discuss the features of our EoS in relation to the predicted neutron star ... More
Nova nucleosynthesis and Galactic evolution of the CNO isotopesFeb 12 2003We study the role played both by novae and single stars in enriching the ISM of the Galaxy with CNO group nuclei, in the framework of a detailed successful model for the chemical evolution of both the Galactic halo and disc. Once all the nucleosynthesis ... More
On the Minimal Messenger ModelFeb 11 1997We study the Minimal Messenger Model, a minimal version of Gauge Mediated Supersymmetry Breaking models. Boundary conditions equal to zero for trilinear and bilinear soft parameters at the messenger scale make this model free from the supersymmetric CP ... More
On the Geometry of Message Passing Algorithms for Gaussian Reciprocal ProcessesMar 30 2016Apr 06 2016Reciprocal processes are acausal generalizations of Markov processes introduced by Bernstein in 1932. In the literature, a significant amount of attention has been focused on developing dynamical models for reciprocal processes. Recently, probabilistic ... More
Topological properties of cellular automata on treesAug 14 2012We prove that there do not exist positively expansive cellular automata defined on the full k-ary tree shift (for k>=2). Moreover, we investigate some topological properties of these automata and their relationships, namely permutivity, surjectivity, ... More
Abstract Interpretation for Probabilistic Termination of Biological SystemsNov 26 2009In a previous paper the authors applied the Abstract Interpretation approach for approximating the probabilistic semantics of biological systems, modeled specifically using the Chemical Ground Form calculus. The methodology is based on the idea of representing ... More
On the Yamabe equation with rough potentialsSep 11 2006We study the existence of non--trivial solutions to the Yamabe equation: $$-\Delta u+ a(x)= \mu u|u|^\frac4{n-2} \hbox{} \mu >0, x\in \Omega \subset {\mathbf R}^n \hbox{with} n\geq 4,$$ $$ u(x)=0 \hbox{on} \partial \Omega$$ under weak regularity assumptions ... More
On the spinfoam expansion in cosmologyNov 16 2009Feb 17 2010We consider the technique introduced in a recent work by Ashtekar, Campiglia and Henderson, which generate a spinfoam-like sum from a Hamiltonian theory. We study the possibility of using it for finding the generalized projector of a constraint on physical ... More
The effects of a Variable IMF on the Chemical Evolution of the GalaxyApr 03 2000In this work we explore the effects of adopting an initial mass function (IMF) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the formation of ... More
Kauffman type invariants for tied linksJul 17 2016Aug 24 2016We define two new invariants for tied links. One of them can be though as an extension of the Kauffman polynomial and the other one as an extension of the Jones polynomial which is constructed via a bracket polynomial for tied links. Also we propose a ... More
Conjugated donor-acceptor chromophores in solution: non-linearity at workNov 12 2001We propose a model that, accounting for the intrinsic non-linearity of the electronic system, is able to rationalize steady-state electronic and vibrational spectra of polar chromophores in solution, as well as time-resolved experiments.
Supramolecular interactions in clusters of polar and polarizable moleculesAug 27 2003We present a model for molecular materials made up of polar and polarizable molecular units. A simple two state model is adopted for each molecular site and only classical intermolecular interactions are accounted for, neglecting any intermolecular overlap. ... More