Results for "M. Angeli"

total 211825took 0.20s
A priori estimates for excitable modelsApr 16 2013The reaction-diffusion system of Fitzhugh Nagumo is considered. The initial- boundary problems with Neumann and Dirichlet conditions are analyzed. By means of an equivalent semilinear integrodifferential equation which characterizes several dissipative ... More
Non linear travelling waves with diffusionMar 04 2012A third order parabolic operator L_\epsilon typical of a non linear wave operator cal L_0 perturbed by viscous terms, is analyzed. Some particular solutions related to L_0 are explicitly determined and the initial value problem for L_\epsilon is considered. ... More
Limit theorems for cloning algorithmsFeb 01 2019May 29 2019Large deviations for additive path functionals of stochastic processes have attracted significant research interest, in particular in the context of stochastic particle systems and statistical physics. Efficient numerical `cloning' algorithms have been ... More
Nonradiative emission and absorption rates of quantum emitters embedded in metallic systems: microscopic description and their determination from electronic transportMay 29 2018We investigate nonradiative emission and absorption rates of two-level quantum emitters embedded in a metal at low temperatures. We obtain the expressions for both nonradiative transition rates and identify a unique, experimentally accessible way to obtain ... More
Asymptotic estimates related to an integro differential equationApr 14 2014The paper deals with an integrodifferential operator which models numerous phenomena in superconductivity, in biology and in viscoelasticity. Initialboundary value problems with Neumann, Dirichlet and mixed boundary conditions are analyzed. An asymptotic ... More
On hereditary models of polymersMar 02 2012An equivalence between an integro-differential operator M and an evolution operator Ln is determined. From this equivalence the fundamental solution of Ln is estimated in terms of the fundamental solution related to the third-order operator L1 whose behavior ... More
Asymptotic analysis for the strip problem related to a parabolic third - order operatorMar 10 2012Aim of this paper is the qualitative analysis of a boundary value problem for a third order non linear parabolic equation which describes several dissipative models. When the source term is linear, the problem is explictly solved by means of a Fourier ... More
Boundary action of automaton groups without singular points and Wang tilingsApr 26 2016We study automaton groups without singular points, that is, points in the boundary for which the map that associates to each point its stabilizer, is not continuous. This is motivated by the problem of finding examples of infinite bireversible automaton ... More
Resonant, broadband and highly efficient optical frequency conversion in semiconductor nanowire gratings at visible and UV wavelengthsMay 11 2019Using a hydrodynamic approach we examine bulk- and surface-induced second and third harmonic generation from semiconductor nanowire gratings having a resonant nonlinearity in the absorption region. We demonstrate resonant, broadband and highly efficient ... More
The Stern diatomic sequence via generalized Chebyshev polynomialsNov 08 2015Nov 15 2015Let a(n) be the Stern's diatomic sequence, and let x1,...,xr be the distances between successive 1's in the binary expansion of the (odd) positive integer n. We show that a(n) is obtained by evaluating generalized Chebyshev polynomials when the variables ... More
On diffusion effects of the perturbed sine-Gordon equation with Neumann boundary conditionsFeb 29 2016The Neumann boundary problem for the perturbed sine-Gordon equation describing the electrodynamics of Josephson junctions has been considered. The behavior of a viscous term, described by a higher-order derivative with small diffusion coefficient, is ... More
On Adversary Robust Consensus protocols through joint-agent interactionsJan 09 2019A generalized family of Adversary Robust Consensus protocols is proposed and analyzed. These are distributed algorithms for multi-agents systems seeking to agree on a common value of a shared variable, even in the presence of faulty or malicious agents ... More
Existence, uniqueness and a priori estimates for a non linear integro-differential equationMar 02 2012The paper deals with the explicit calculus and the properties of the fundamental solution K of a parabolic operator related to a semilinear equation that models reaction diffusion systems with excitable kinetics. The initial value problem in all of the ... More
On the Fitzhugh-Nagumo modelFeb 26 2012The initial value problem P0, in all of the space, for the spatio - temporal FitzHugh - Nagumo equations is analyzed. When the reaction kinetics of the model can be outlined by means of piecewise linear approximations, then the solution of P0 is explicitly ... More
Diffusion effects on a superconductive modelNov 06 2012A superconductive model characterized by a third order parabolic operator L" is analysed. When the viscous terms, represented by higher - order deriva- tives, tend to zero, a hyperbolic operator L0 appears. Furthermore, if P" is the Dirichlet initial ... More
Asymptotic effects of boundary perturbations in excitable systemsApr 14 2013A Neumann problem in the strip for the Fitzhugh Nagumo system is consid- ered. The transformation in a non linear integral equation permits to deduce a priori estimates for the solution. A complete asymptotic analysis shows that for large t the effects ... More
Optimal dividends with partial information and stopping of a degenerate reflecting diffusionMay 30 2018Mar 29 2019We study the optimal dividend problem for a firm's manager who has partial information on the profitability of the firm. The problem is formulated as one of singular stochastic control with partial information on the drift of the underlying process and ... More
Wreath product of matricesJul 09 2015We introduce a new matrix product, that we call the wreath product of matrices. The name is inspired by the analogous product for graphs, and the following important correspondence is proven: the wreath product of the adjacency matrices of two graphs ... More
The dividend problem with a finite horizonSep 06 2016Nov 23 2017We characterise the value function of the optimal dividend problem with a finite time horizon as the unique classical solution of a suitable Hamilton-Jacobi-Bellman equation. The optimal dividend strategy is realised by a Skorokhod reflection of the fund's ... More
Valley Jahn-Teller effect in twisted bilayer grapheneApr 12 2019The surprising insulating and superconducting states of narrow-band graphene twisted bilayers have been mostly discussed so far in terms of strong electron correlation, with little or no attention to phonons and electron-phonon effects. We found that, ... More
Shuffling matrices, Kronecker product and Discrete Fourier TransformMay 31 2016We define and investigate a family of permutations matrices, called shuffling matrices, acting on a set of $N=n_1\cdots n_m$ elements, where $m\geq 2$ and $n_i\geq 2$ for any $i=1,\ldots, m$. These elements are identified with the vertices of the $m$-th ... More
Playing with ghosts in a Dynkin gameMay 16 2019We study a class of optimal stopping games (Dynkin games) of preemption type, with uncertainty about the existence of competitors. The set-up is well-suited to model, for example, real options in the context of investors who do not want to publicly reveal ... More
Valley Jahn-Teller effect in twisted bilayer grapheneApr 12 2019Apr 16 2019The surprising insulating and superconducting states of narrow-band graphene twisted bilayers have been mostly discussed so far in terms of strong electron correlation, with little or no attention to phonons and electron-phonon effects. We found that, ... More
The lumpability property for a family of Markov chains on poset block structuresApr 15 2013We construct different classes of lumpings for a family of Markov chain products which reflect the structure of a given finite poset. We use essentially combinatorial methods. We prove that, for such a product, every lumping can be obtained from the action ... More
Weighted spanning trees on some self-similar graphsJun 30 2010We compute the complexity of two infinite families of finite graphs: the Sierpi\'{n}ski graphs, which are finite approximations of the well-known Sierpi\'nsky gasket, and the Schreier graphs of the Hanoi Towers group $H^{(3)}$ acting on the rooted ternary ... More
Freeness of automata groups vs boundary dynamicsOct 22 2014Nov 03 2014We prove that the boundary dynamics of the (semi)group generated by the enriched dual transducer characterizes the algebraic property of being free for an automaton group. We specialize this result to the class of bireversible transducers and we show ... More
Data Mining in Gamma Astrophysics ExperimentsMar 24 2005Data mining techniques, including clustering and classification tasks, for the automatic information extraction from large datasets are increasingly demanded in several scientific fields. In particular, in the astrophysical field, large archives and digital ... More
Perspects in astrophysical databasesFeb 09 2004Astrophysics has become a domain extremely rich of scientific data. Data mining tools are needed for information extraction from such large datasets. This asks for an approach to data management emphasizing the efficiency and simplicity of data access; ... More
New Approach to the Stability of Chemical Reaction Networks: Piecewise Linear in Rates Lyapunov FunctionsJul 02 2014Sep 07 2016Piecewise-Linear in Rates (PWLR) Lyapunov functions are introduced for a class of Chemical Reaction Networks (CRNs). In addition to their simple structure, these functions are robust with respect to arbitrary monotone reaction rates, of which mass-action ... More
Analysing Multiple Epidemic Data SourcesAug 13 2018Evidence-based knowledge of infectious disease burden, including prevalence, incidence, severity and transmission, in different population strata and locations, and possibly in real time, is crucial to the planning and evaluation of public health policies. ... More
Robust Lyapunov Functions for Reaction Networks: An Uncertain System FrameworkSep 07 2015We present a framework to transform the problem of finding a Lyapunov function of a Chemical Reaction Network (CRN) in concentration coordinates with arbitrary monotone kinetics into finding a common Lyapunov function for a linear parameter varying system ... More
Data Management and Mining in Astrophysical DatabasesJul 12 2003Jul 16 2003We analyse the issues involved in the management and mining of astrophysical data. The traditional approach to data management in the astrophysical field is not able to keep up with the increasing size of the data gathered by modern detectors. An essential ... More
Wave hierarchies in viscoelasticityMar 02 2012An evolution operator L_n with n arbitrary, typical of several models, is analyzed. When n= 1, the operator characterizes the standard linear solid of viscoelasticity, whose properties are already established in previous papers. The fundamental solution ... More
Non linear problems in dissipative modelsMar 09 2012Aim of the paper is the qualitative analysis of a quasi-linear parabolic third order equation, which describes the evolution in a large class of dissipative models. As examples of some typical boundary problems, both Dirichlet's and Neumann's type boundary ... More
Existence and uniqueness results for a class of non linear modelsMar 11 2012The qualitative analysis of the initial value problem P related to a non linear third order parabolic equation typical of diffusive models is discussed. Some basic properties of the the fundamental solution of a related linear operator are determined ... More
Optimal stopping of a Hilbert space valued diffusion: an infinite dimensional variational inequalityJul 03 2012Jan 31 2015A finite horizon optimal stopping problem for an infinite dimensional diffusion $X$ is analyzed by means of variational techniques. The diffusion is driven by a SDE on a Hilbert space $\mathcal{H}$ with a non-linear diffusion coefficient $\sigma(X)$ and ... More
Limit theorems for cloning algorithmsFeb 01 2019Large deviations for additive path functionals of stochastic processes have attracted significant research interest, in particular in the context of stochastic particle systems and statistical physics. Efficient numerical `cloning' algorithms have been ... More
Optimal Boundary Surface for Irreversible Investment with Stochastic CostsJun 17 2014Jan 08 2017This paper examines a Markovian model for the optimal irreversible investment problem of a firm aiming at minimizing total expected costs of production. We model market uncertainty and the cost of investment per unit of production capacity as two independent ... More
A Non Convex Singular Stochastic Control Problem and its Related Optimal Stopping BoundariesMay 10 2014Nov 12 2014Equivalences are known between problems of singular stochastic control (SSC) with convex performance criteria and related questions of optimal stopping, see for example Karatzas and Shreve [SIAM J. Control Optim. 22 (1984)]. The aim of this paper is to ... More
Ends of Schreier graphs and cut-points of limit spaces of self-similar groupsJan 27 2016Every self-similar group acts on the space $X^\omega$ of infinite words over some alphabet $X$. We study the Schreier graphs $\Gamma_w$ for $w\in X^\omega$ of the action of self-similar groups generated by bounded automata on the space $X^\omega$. Using ... More
A numerical scheme for stochastic differential equations with distributional driftJun 26 2019In this paper we present a scheme for the numerical solution of stochastic differential equations (SDEs) with distributional drift. The approximating process, obtained by the scheme, converges in law to the (virtual) solution of the SDE in a general multi-dimensional ... More
Photon propagation and the VHE gamma-ray spectra of blazars: how transparent is really the Universe?Jul 26 2008Nov 23 2008Recent findings by gamma-ray Cherenkov telescopes suggest a higher transparency of the Universe to very-high-energy (VHE) photons than expected from current models of the Extragalactic Background Light. It has been shown that such transparency can be ... More
On fast and slow times in models with diffusionMar 09 2012The linear Kelvin{Voigt operator L_\epsilon is a typical example of wave operator L_0 perturbed by higher-order viscous terms as \epsilonu_xxt. If P\epsilon is a prefixed boundary value problem for L_\epsilon, when \epsilon = 0, L_\epsilon turns into ... More
Importance of axion-like particles for very-high-energy astrophysicsJul 02 2012Several extensions of the Standard Model predict the existence of Axion-Like Particles (ALPs), very light spin-zero bosons with a two-photon coupling. ALPs can give rise to observable effects in very-high-energy astrophysics. Above roughly 100 GeV the ... More
A solvable two-dimensional singular stochastic control problem with non convex costsNov 10 2014Oct 28 2015In this paper we provide a complete theoretical analysis of a two-dimensional degenerate non convex singular stochastic control problem. The optimisation is motivated by a storage-consumption model in an electricity market, and features a stochastic real-valued ... More
Study of dynamical supersymmetry breaking for the two dimensional lattice Wess-Zumino modelDec 13 2004A new approach to the study of the transition point in a class of two dimensional Wess-Zumino models is presented. The method is based on the calculation of rigorous lower bounds on the ground state energy density in the infinite lattice limit. Such bounds ... More
Rare event simulation for stochastic dynamics in continuous timeOct 01 2018Large deviations for additive path functionals and convergence properties for numerical approaches based on population dynamics have attracted recent research interest. The aim of this paper is twofold. Extending results from the literature of particle ... More
Homogeneous isotropic turbulence in dilute polymers: scale by scale budgetAug 09 2002The turbulent energy cascade in dilute polymers solution is addressed here by considering a direct numerical simulation of homogeneous isotropic turbulence of a FENE-P fluid in a triply periodic box. On the basis of the DNS data, a scale by scale analysis ... More
Rare event simulation for stochastic dynamics in continuous timeOct 01 2018Jun 10 2019Large deviations for additive path functionals of stochastic dynamics and related numerical approaches have attracted significant recent research interest. We focus on the question of convergence properties for cloning algorithms in continuous time, and ... More
Decoherence and collective effects in critical mediaMar 29 2019We investigate the influence of critical phenomena on two distinct physical processes: the center-of-mass decoherence of a single emitter, and the collective radiation of two emitters. We address these different physical mechanisms with an unified formalism ... More
Self-Organising Networks for Classification: developing Applications to Science Analysis for Astroparticle PhysicsFeb 09 2004Physics analysis in astroparticle experiments requires the capability of recognizing new phenomena; in order to establish what is new, it is important to develop tools for automatic classification, able to compare the final result with data from different ... More
Evidence synthesis for stochastic epidemic modelsJun 08 2017In recent years the role of epidemic models in informing public health policies has progressively grown. Models have become increasingly realistic and more complex, requiring the use of multiple data sources to estimate all quantities of interest. This ... More
On Path-Complete Lyapunov Functions: Geometry and ComparisonDec 01 2017We study optimization-based criteria for the stability of switching systems, known as Path-Complete Lyapunov Functions, and ask the question "can we decide algorithmically when a criterion is less conservative than another". Our contribution is twofold. ... More
Path-Complete Graphs and Common Lyapunov FunctionsDec 13 2016A Path-Complete Lyapunov Function is an algebraic criterion composed of a finite number of functions, called its pieces, and a directed, labeled graph defining Lyapunov inequalities between these pieces. It provides a stability certificate for discrete-time ... More
Experimental test of the no signaling theoremMay 14 2007May 17 2007In 1981 N. Herbert proposed a gedanken experiment in order to achieve by the ''First Laser Amplified Superluminal Hookup'' (FLASH) a faster than light communication (FTL) by quantum nonlocality. The present work reports the first experimental realization ... More
Excited States in 52Fe and the Origin of the Yrast Trap at I=12+Dec 11 1997Excited states in 52Fe have been determined up to spin 10\hbar in the reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the GASP array. The excitation energy of the yrast 10+ state has been determined to be 7.381 MeV, almost ... More
Automaton Semigroups and Groups: on the Undecidability of Problems Related to Freeness and FinitenessDec 20 2017Apr 16 2019In this paper, we study algorithmic problems for automaton semigroups and automaton groups related to freeness and finiteness. In the course of this study, we also exhibit some connections between the algebraic structure of automaton (semi)groups and ... More
Emergent $\text{D}_6$ symmetry in fully-relaxed magic-angle twisted bilayer grapheneSep 28 2018Oct 23 2018We present a tight-binding calculation of a twisted bilayer graphene at magic angle $\theta\sim 1.08^\circ$, allowing for full, in- and out-of-plane, relaxation of the atomic positions. The resulting band structure displays as usual four narrow mini bands ... More
Isospin Symmetry violation in mirror E1 transitions: Coherent contributions from the Giant Isovector Monopole Resonance in 67As - 67SeSep 24 2012The assumption of an exact isospin symmetry would imply equal strengths for mirror E1 transitions (at least, in the long-wavelength limit). Actually, large violations of this symmetry rule have been indicated by a number of experimental results, the last ... More
Drag Reduction by Polymers in Turbulent Channel Flows: Energy Redistribution Between Invariant Empirical ModesOct 29 2002We address the phenomenon of drag reduction by dilute polymeric additive to turbulent flows, using Direct Numerical Simulations (DNS) of the FENE-P model of viscoelastic flows. It had been amply demonstrated that these model equations reproduce the phenomenon, ... More
Review of methods for assessing the causal effect of binary interventions from aggregate time-series observational dataApr 20 2018Researchers are often interested in assessing the impact of an intervention on an outcome of interest in situations where the intervention is non-randomised, information is available at an aggregate level, the intervention is only applied to one or few ... More
Search and analysis of blue straggler stars in open clustersAug 22 2006Aims: This paper presents a new homogeneous catalogue of blue straggler stars (BSS) in Galactic open clusters. Methods: Photometric data for 216 clusters were collected from the literature and 2782 BSS candidates were extracted from 76 of them. Results: ... More
Neural networks for gamma-hadron separation in MAGICMar 24 2005Neural networks have proved to be versatile and robust for particle separation in many experiments related to particle astrophysics. We apply these techniques to separate gamma rays from hadrons for the MAGIC Cerenkov Telescope. Two types of neural network ... More
MultiBUGS: A parallel implementation of the BUGS modelling framework for faster Bayesian inferenceApr 11 2017Nov 29 2018MultiBUGS (https://www.multibugs.org) is a new version of the general-purpose Bayesian modelling software BUGS that implements a generic algorithm for parallelising Markov chain Monte Carlo (MCMC) algorithms to speed up posterior inference of Bayesian ... More
Isospin symmetry breaking at high spins in the mirror pair 67Se and 67AsNov 27 2010Recent experimental data have revealed large mirror energy differences (MED) between high-spin states in the mirror nuclei 67Se and 67As, the heaviest pair where MED have been determined so far. The MED are generally attributed to the isospin symmetry ... More
Multinucleon transfer reactions in closed-shell nucleiJul 03 2007Multinucleon transfer reactions in 40Ca+96Zr and 90Zr+208Pb have been measured at energies close to the Coulomb barrier in a high resolution gamma-particle coincidence experiment. The large solid angle magnetic spectrometer PRISMA coupled to the CLARA ... More
Plasmon-Assisted Suppression of Surface Trap States and Enhanced Band-Edge Emission in a Bare CdTe Quantum DotMar 08 2019Colloidal quantum dots have emerged as a versatile photoluminescent and optoelectronic material. Issues like fluorescence intermittency, non-radiative Auger recombination and surface traps are commonly addressed by growing a wide-bandgap shell around ... More
Conflict diagnostics for evidence synthesis in a multiple testing frameworkFeb 23 2017Sep 13 2017Evidence synthesis models that combine multiple datasets of varying design, to estimate quantities that cannot be directly observed, require the formulation of complex probabilistic models that can be expressed as graphical models. An assessment of whether ... More
Conflict Diagnostics in Directed Acyclic Graphs, with Applications in Bayesian Evidence SynthesisOct 02 2013Complex stochastic models represented by directed acyclic graphs (DAGs) are increasingly employed to synthesise multiple, imperfect and disparate sources of evidence, to estimate quantities that are difficult to measure directly. The various data sources ... More
Estimation of HIV Burden through Bayesian Evidence SynthesisMay 19 2014Planning, implementation and evaluation of public health policies to control the human immunodeficiency virus (HIV) epidemic require regular monitoring of disease burden. This includes the proportion living with HIV, whether diagnosed or not, and the ... More
Model surgery: joining and splitting models with Markov meldingJul 22 2016Sep 02 2016Analysing multiple evidence sources is often feasible only via a modular approach, with separate submodels specified for smaller components of the available evidence. Here we introduce a generic framework that enables fully Bayesian analysis in this setting. ... More
Sources and fluxes of scale-energy in the overlap layer of wall turbulenceMar 30 2017Direct Numerical Simulations of turbulent channel flows at friction Reynolds number 550, 1000, 1500, are used to analyse the turbulent production, transfer and dissipation mechanisms in the compound space of scales and wall-distances by means of the Kolmogorov ... More
Plasmon-Assisted Suppression of Surface Trap States and Enhanced Band-Edge Emission in a Bare CdTe Quantum DotMar 08 2019Apr 16 2019Colloidal quantum dots have emerged as a versatile photoluminescent and optoelectronic material. Limitations like fluorescence intermittency, non-radiative Auger recombination and surface traps are commonly addressed by growing a wide-bandgap shell. However, ... More
On the existence of superradiant excitonic states in microtubulesAug 12 2018Microtubules are biological protein polymers with critical and diverse functions. Their structures share some similarities with photosynthetic antenna complexes, particularly in the ordered arrangement of photoactive molecules with large transition dipole ... More
Joining and splitting models with Markov meldingJul 22 2016Sep 12 2017Analysing multiple evidence sources is often feasible only via a modular approach, with separate submodels specified for smaller components of the available evidence. Here we introduce a generic framework that enables fully Bayesian analysis in this setting. ... More
All-Sky-ASTROGAM: The MeV Gamma-Ray Companion to Multimessenger AstronomyMay 19 2019All-Sky-ASTROGAM is a gamma-ray observatory operating in a broad energy range, 100 keV to a few hundred MeV, recently proposed as the "Fast" (F) mission of the European Space Agency for a launch in 2028 to an L2 orbit. The scientific payload is composed ... More
Transition probabilities in the X(5) candidate $^{122}$BaOct 21 2010To investigate the possible X(5) character of 122Ba, suggested by the ground state band energy pattern, the lifetimes of the lowest yrast states of 122Ba have been measured, via the Recoil Distance Doppler-Shift method. The relevant levels have been populated ... More
A Homogenous Set of Globular Cluster Relative Distances and ReddeningsAug 25 2004We present distance modulus and reddening determinations for 72 Galactic globular clusters from the homogeneous photometric database of Piotto et al. (2002), calibrated to the HST flight F439W and F555W bands. The distances have been determined by comparison ... More
The Red Giant Branch Luminosity Function BumpAug 25 2003We present observational estimates of the magnitude difference between the luminosity function RGB bump and the HB (Delta(bump-zahb)), and of star counts in the bump region (R_bump), for a sample of 54 Galactic globular clusters (GCs) observed by the ... More
Is our Sun a Singleton?Sep 19 2007Most stars are formed in a cluster or association, where the number density of stars can be high. This means that a large fraction of initially-single stars will undergo close encounters with other stars and/or exchange into binaries. We describe how ... More
Studies on a silicon-photomultiplier-based camera for Imaging Atmospheric Cherenkov TelescopesJan 13 2017Imaging Atmospheric Cherenkov Telescopes (IACTs) represent a class of instruments which are dedicated to the ground-based observation of cosmic VHE gamma ray emission based on the detection of the Cherenkov radiation produced in the interaction of gamma ... More
Discovery of $^{68}$Br in secondary reactions of radioactive beamsJun 10 2019The proton-rich isotope 68Br was discovered in secondary fragmentation reactions of fast radioactive beams. Proton-rich secondary beams of 70,71,72Kr and 70Br, produced at the RIKEN Nishina Center and identified by the BigRIPS fragment separator, impinged ... More
Hadronic Events at LEPAug 05 2003The hadronic events collected by LEP between 1989 and 2000 have changed dramatically our understanding of QCD, which has now been established as a part of the Standard Model. Still in many sectors (nonperturbative in particular) science analysis needs ... More
Study of Hadronic Decays of the Z Boson at LEPAug 04 2000This report summarizes four recent papers on the characteristics of the hadronic decays of the Z by the LEP collaborations ALEPH, DELPHI and OPAL.
(Very)-High-Energy Gamma-Ray Astrophysics: the FutureJan 12 2016Several projects planned or proposed can significantly expand our knowledge of the high-energy Universe in gamma rays. Construction of the Cherenkov telescope array CTA is started, and other detectors are planned which will use the reconstruction of extensive ... More
On exponentially shaped Josephson junctionsFeb 23 2012The paper deals with a third order semilinear equation which char- acterizes exponentially shaped Josephson junctions in superconductivity. The initial-boundary problem with Dirichlet conditions is analyzed. When the source term F is a linear function, ... More
Recent results from VHE gamma astrophysics related to fundamental physics and cosmic raysApr 27 2011High-energy photons are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the most violent phenomena in the universe has impressively progressed thanks to the advent of new ... More
GLAST, the Gamma-ray Large Area Space TelescopeSep 18 2000GLAST, a detector for cosmic gamma rays in the range from 20 MeV to 300 GeV, will be launched in space in 2005. Breakthroughs are expected in particular in the study of particle acceleration mechanisms in space and of gamma ray bursts, and maybe on the ... More
On a parabolic operator of dissipative systemsJul 07 2013A parabolic integro differential operator operator L suitable to describe many phenomena in various physical fields,is considered. By means of equivalence between L and the third order equation which describe the evolution inside an exponentially shaped ... More
On a non linear third - order parabolic equationJul 09 2012Aim of this paper is the qualitative analysis of the solution of a boundary value problem for a third-order non linear parabolic equation which describes several dissipative models. When the source term is linear, the problem is explictly solved by means ... More
On the transition from parabolicity to hyperbolicity for a nonlinear equation under Neumann boundary conditionsOct 21 2018An integro differential equation which is able to describe the evolution of a large class of dissipative models, is considered. By means of an equivalence, the focus shifts to the perturbed sine- Gordon equation that in superconductivity finds interesting ... More
A note on the continuity of free-boundaries in finite-horizon optimal stopping problems for one dimensional diffusionsMay 06 2013We provide sufficient conditions for the continuity of the free-boundary in a general class of finite-horizon optimal stopping problems arising for instance in finance and economics. The underlying process is a strong solution of one dimensional, time-homogeneous ... More
Small scale dynamics of a shearless turbulent/non-turbulent interface in dilute polymer solutionsDec 18 2016Jul 17 2017We study the physics of turbulent/non-turbulent interface of an isolated turbulent region in dilute polymer solutions and Newtonian fluid. The performance of a FENE-P model with a localized homogeneous forcing is verified using the specially designed ... More
Optimal dividends with partial information and stopping of a degenerate reflecting diffusionMay 30 2018Motivated by the optimal dividend problem, we study a problem of singular stochastic control with partial information on the drift of the underlying process and with absorption. In the Markovian formulation, we have a 2-dimensional degenerate diffusion, ... More
Fundamental Physics With Cosmic High-Energy Gamma RaysOct 26 2016High-energy photons (above the MeV) are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the high-energy gamma-ray sky has impressively progressed thanks to the advent of ... More
Interconnection Effects in Multiparticle Production from WW Events at LEPMay 07 1998Interactions between the products of the hadronic decays of different Ws in WW pair events can occur at several stages: from the colour rearrangement between the quarks coming from the primary branching, to the gluon exchange during the parton cascade, ... More
The simulation of astroparticle experiments and the GEANT4 toolkitDec 15 2001The new generation of astroparticle experiments will use technologies common to High Energy Physics. Among such technologies a central place is given to the role of simulation.
On a Model of Superconductivity and BiologyMar 02 2012The paper deals with a semilinear integrodifferential equation that characterizes several dissipative models of Viscoelasticity, Biology and Superconductivity. The initial - boundary problem with Neumann conditions is analyzed. When the source term F ... More
Mathematical Contributions to the Dynamics of the Josephson Junctions: State of the Art and Open ProblemsSep 10 2015Mathematical models related to some Josephson junctions are pointed out and attention is drawn to the solutions of certain initial boundary problems and to some of their estimates. In addition, results of rigorous analysis of the behaviour of these solutions ... More
Convergence in strongly monotone systems with an increasing first integralJun 01 2009In this paper we generalise a useful result due to J. Mierczynski which states that for a strictly cooperative system on the positive orthant, with increasing first integral, all bounded orbits are convergent. Moreover any equilibrium attracts its entire ... More