Results for "Michele Di Fraia"

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Photophysics of indole upon x-ray absorptionFeb 08 2018A photofragmentation study of gas-phase indole (C$_8$H$_7$N) upon single-photon ionization at a photon energy of 420 eV is presented. Indole was primarily inner-shell ionized at its nitrogen and carbon $1s$ orbitals. Electrons and ions were measured in ... More
High-repetition-rate and high-photon-flux 70 eV high-harmonic source for coincidence ion imaging of gas-phase moleculesFeb 11 2016Apr 28 2016Unraveling and controlling chemical dynamics requires techniques to image structural changes of molecules with femtosecond temporal and picometer spatial resolution. Ultrashort-pulse x-ray free-electron lasers have significantly advanced the field by ... More
The Importance of the Pre-exponential Factor in Semiclassical Molecular DynamicsDec 02 2016This paper deals with the critical issue of approximating the pre-exponential factor in semiclassical molecular dynamics. The pre-exponential factor is important because it accounts for the quantum contribution to the semiclassical propagator of the classical ... More
A computational spectral approach to interest rate modelsAug 25 2015The Polynomial Chaos Expansion (PCE) technique recovers a finite second order random variable exploiting suitable linear combinations of orthogonal polynomials which are functions of a given stochas- tic quantity {\xi}, hence acting as a kind of random ... More
EUV ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization and electron energy-loss spectraMay 16 2013The ionization dynamics of pure He nanodroplets irradiated by EUV radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence (VMI-PEPICO) spectroscopy. We present photoelectron energy spectra and angular distributions measured ... More
Critical Points for Elliptic Equations with Prescribed Boundary ConditionsNov 21 2016This paper concerns the existence of critical points for solutions to second order elliptic equations of the form $\nabla\cdot \sigma(x)\nabla u=0$ posed on a bounded domain $X$ with prescribed boundary conditions. In spatial dimension $n=2$, it is known ... More
Strong thermal leptogenesis and the absolute neutrino mass scaleJan 23 2014Mar 24 2014We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass $m_1 \gtrsim ... More
Energy and water vapor transport across a simplified cloud-clear air interfaceFeb 24 2015We consider a simplified physics of the could interface where condensation, evaporation and radiation are neglected and momentum, thermal energy and water vapor transport is represented in terms of the Boussinesq model coupled to a passive scalar transport ... More
On the convergence of the affine hull of the Chvátal-Gomory closuresOct 23 2012Nov 08 2012Given an integral polyhedron P and a rational polyhedron Q living in the same n-dimensional space and containing the same integer points as P, we investigate how many iterations of the Chv\'atal-Gomory closure operator have to be performed on Q to obtain ... More
Reverse Chvátal-Gomory rankNov 02 2012Sep 26 2014We introduce the reverse Chv\'atal-Gomory rank r*(P) of an integral polyhedron P, defined as the supremum of the Chv\'atal-Gomory ranks of all rational polyhedra whose integer hull is P. A well-known example in dimension two shows that there exist integral ... More
Estimating the cost of generic quantum pre-image attacks on SHA-2 and SHA-3Mar 30 2016We investigate the cost of Grover's quantum search algorithm when used in the context of pre-image attacks on the SHA-2 and SHA-3 families of hash functions. Our cost model assumes that the attack is run on a surface code based fault-tolerant quantum ... More
Multistep kinetic self-assembly of DNA-coated colloidsFeb 22 2013Self-assembly is traditionally described as the process through which an initially disordered system relaxes towards an equilibrium ordered phase only driven by local interactions between its building blocks. However, This definition is too restrictive. ... More
Enabling Mutation Testing for Android AppsJul 27 2017Aug 01 2017Mutation testing has been widely used to assess the fault-detection effectiveness of a test suite, as well as to guide test case generation or prioritization. Empirical studies have shown that, while mutants are generally representative of real faults, ... More
Recent Results from CDFDec 06 1999We present the latest results from the CDF experiment at the Tevatron Collider in \ppbar collisions at $\sqrt{s} = 1.8$ TeV. The large data sample collected during Run 1, from 1992 until 1995, allows measurements in many domains of high-energy physics. ... More
A New Scintillator Tile/Fiber Preshower Detector for the CDF Central CalorimeterNov 05 2004Aug 19 2005A detector designed to measure early particle showers has been installed in front of the central CDF calorimeter at the Tevatron. This new preshower detector is based on scintillator tiles coupled to wavelength-shifting fibers read out by multi-anode ... More
Beyond Fisher: exact sampling distributions of the maximum-likelihood estimator in gravitational-wave parameter estimationAug 04 2011Nov 04 2011Gravitational-wave astronomers often wish to characterize the expected parameter-estimation accuracy of future observations. The Fisher matrix provides a lower bound on the spread of the maximum-likelihood estimator across noise realizations, as well ... More
Synthetic LISA: Simulating Time Delay Interferometry in a Model LISAJul 27 2004Jan 05 2005We report on three numerical experiments on the implementation of Time-Delay Interferometry (TDI) for LISA, performed with Synthetic LISA, a C++/Python package that we developed to simulate the LISA science process at the level of scientific and technical ... More
Prospects for gravitational-wave observations of neutron-star tidal disruption in neutron-star/black-hole binariesDec 08 1999Apr 19 2000For an inspiraling neutron-star/black-hole binary (NS/BH), we estimate the gravity-wave frequency f_td at the onset of NS tidal disruption. We model the NS as a tidally distorted, homogeneous, Newtonian ellipsoid on a circular, equatorial geodesic around ... More
Use and Abuse of the Fisher Information Matrix in the Assessment of Gravitational-Wave Parameter-Estimation ProspectsMar 15 2007Feb 04 2008The Fisher-matrix formalism is used routinely in the literature on gravitational-wave detection to characterize the parameter-estimation performance of gravitational-wave measurements, given parametrized models of the waveforms, and assuming detector ... More
Gutzwiller description of non-magnetic Mott insulators: a dimer lattice modelApr 11 2007We introduce a novel extension of the Gutzwiller variational wavefunction able to deal with insulators that escape any mean-field like description, as for instance non-magnetic insulators. As an application, we study the Mott transition from a paramagnetic ... More
Advanced engineering design as practiced today from the view point of the CERN Industrial Liaison OfficerJan 16 2012After an introduction about CERN, a brief description of the Large Hadron Collider(LHC) it is reviewed. Pros and cons of a few advanced engineering design cases are taken in consideration together with the involvement of the European Industry. The conclusion ... More
Binary dynamics from spin1-spin2 coupling at fourth post-Newtonian orderJul 21 2011Jun 25 2014We calculate via the effective field theory (EFT) approach the next-to-next-to-leading order (NNLO) spin1-spin2 conservative potential for a binary. Hereby, we first demonstrate the ability of the EFT approach to go at NNLO in post-Newtonian (PN) corrections ... More
Next-to-leading order gravitational spin1-spin2 coupling with Kaluza-Klein reductionFeb 11 2008Sep 24 2010We use the recently proposed Kaluza-Klein (KK) reduction over the time dimension, within an effective field theory (EFT) approach, to calculate the next to leading order (NLO) gravitational spin1-spin2 interaction between two spinning compact objects. ... More
Zero-point quantum fluctuations and dark energyApr 11 2010Feb 25 2011In the Hamiltonian formulation of General Relativity the energy associated to an asymptotically flat space-time with metric $g_{\mu\nu}$ is related to the Hamiltonian $H_{GR}$ by $E=H_{GR}[g_{\mu\nu}]-H_{\rm GR}[\eta_{\mu\nu}]$, where the subtraction ... More
High-Energy Physics with Gravitational-Wave ExperimentsMar 07 1998We discuss the possible relevance of gravitational-wave (GW) experiments for physics at very high energy. We examine whether, from the experience gained with the computations of various specific relic GW backgrounds, we can extract statements and order ... More
The graviton background at early times in string cosmologyJan 14 1997We discuss some peculiar properties of the stochastic graviton background predicted by string cosmology. At Planckian times, for the values of the parameters of the model which are more interesting for the detection in gravitational wave experiments, ... More
The physical interpretation of the spectrum of black hole quasinormal modesNov 20 2007Mar 13 2008When a classical black hole is perturbed, its relaxation is governed by a set of quasinormal modes with complex frequencies \omega= \omega_R+i\omega_I. We show that this behavior is the same as that of a collection of damped harmonic oscillators whose ... More
The Atick-Witten free energy, closed tachyon condensation and deformed Poincare' symmetryMay 01 2002The dependence of the free energy of string theory on the temperature at T much larger than the Hagedorn temperature was found long ago by Atick and Witten and is $F(T)\sim \Lambda T^2$, where $\Lambda$ diverges because of a tachyonic instability. We ... More
Black holes as quantum membranes: path integral approachApr 28 1994We describe the horizon of a quantum black hole in terms of a dynamical surface which defines the boundary of space-time as seen by external static observers, and we define a path integral in the presence of this dynamical boundary. Using renormalization ... More
Gabor Frame Decomposition of Evolution Operators and ApplicationsAug 12 2013Feb 25 2014We compute the Gabor matrix for Schr\"odinger-type evolution operators. Precisely, we analyze the Heat Equation, already presented in \cite{2012arXiv1209.0945C}, giving the exact expression of the Gabor matrix which leads to better numerical evaluations. ... More
Experimental results on diffraction at CDFSep 08 2010Diffractive events are studied by means of identification of one or more rapidity gaps and/or a leading antiproton. Measurements of soft and hard diffractive processes have been performed at the Tevatron $p\bar p$ collider and presented. We report on ... More
QCD Results from the CDF Experiment at sqrt{s}=1.96 TeVApr 22 2003First QCD results obtained from the CDF experiment using Run II data are reported. The Run II physics program at the Tevatron started in the spring of 2001, with protons and anti-protons colliding at an energy of sqrt(s) = 1.96 TeV. The size of the data ... More
What can we learn about neutron stars from gravity-wave observations?Feb 11 2002In the next few years, the first detections of gravity-wave signals using Earth-based interferometric detectors will begin to provide precious new information about the structure and dynamics of compact bodies such as neutron stars. The intrinsic weakness ... More
A homotopy for a complex of free Lie algebrasMar 06 2011Jul 12 2011Using the Guichardet construction, we compute the cohomology groups of a complex of free Lie algebras introduced by Alekseev and Torossian.
Applications of Equivariant CohomologyJul 17 2006Aug 14 2006We will discuss the equivariant cohomology of a manifold endowed with the action of a Lie group. Localization formulae for equivariant integrals are explained by a vanishing theorem for equivariant cohomology with generalized coefficients. We then give ... More
Superconductivity from doping a spin liquid insulator: a simple one-dimensional exampleMar 15 1996Mar 28 1996We study the phase diagram of a one-dimensional Hubbard model where, in addition to the standard nearest neighbor hopping $t$, we also include a next-to-nearest neighbor hopping $t'$. For strong enough on-site repulsion, this model has a transition at ... More
Hydrophobicity and Unique Folding of Selected PolymersJan 05 1998In suitable environments, proteins, nucleic acids and certain synthetic polymers fold into unique conformations. This work shows that it is possible to construct lattice models of foldable heteropolymers by expressing the energy only in terms of individual ... More
A conic bundle degenerating on the Kummer surfaceFeb 18 2007Let $C$ be a genus 2 curve and $\su$ the moduli space of semi-stable rank 2 vector bundles on $C$ with trivial determinant. In \cite{bol:wed} we described the parameter space of non stable extension classes (invariant with respect to the hyperelliptic ... More
Black Holes as Quantum MembranesJan 25 1994We propose a quantum description of black holes. The degrees of freedom to be quantized are identified with the microscopic degrees of freedom of the horizon, and their dynamics is governed by the action of the relatistic bosonic membrane in $D=4$. We ... More
Quantum Groups, Gravity, and the Generalized Uncertainty PrincipleMay 28 1993Nov 04 1993We investigate the relationship between the generalized uncertainty principle in quantum gravity and the quantum deformation of the Poincar\'e algebra. We find that a deformed Newton-Wigner position operator and the generators of spatial translations ... More
Phantom dark energy from non-local infrared modifications of General RelativityJul 15 2013Jan 31 2014We discuss the cosmological consequences of a model based on a non-local infrared modification of Einstein equations. We find that the model generates a dynamical dark energy that can account for the presently observed value of $\Omega_{\rm DE}$, without ... More
New interactions: past and future experimentsOct 20 2008In this talk I will review the present status and future perspectives of some popular extensions of the conventional three-neutrino oscillation scenario, from a purely phenomenological point of view. For concreteness I will focus only on three specific ... More
Next-to-leading order gravitational spin-orbit coupling in an effective field theory approachJun 21 2010Nov 03 2010We use an effective field theory (EFT) approach to calculate the next to leading order (NLO) gravitational spin-orbit interaction between two spinning compact objects. The NLO spin-orbit interaction provides the most computationally complex sector of ... More
Constructing free actions of p-groups on products of spheresNov 04 2010We prove that, for p an odd prime, every finite p-group of rank 3 acts freely on a finite complex X homotopy equivalent to a product of three spheres.
On Weddle Surfaces And Their ModuliJan 11 2006Oct 04 2006The Weddle surface is classically known to be a birational (partially desingularized) model of the Kummer surface. In this note we go through its relations with moduli spaces of abelian varieties and of rank two vector bundles on a genus 2 curve. First ... More
The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in SpaceOct 13 2011The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in ... More
Polysymplectic spaces, s-Kahler manifolds and lagrangian fibrationsJun 21 2000In the first part of this paper we begin the study of polysymplectic manifolds, and of their relationship with PDE's. This notion provides a generalization of symplectic manifolds which is very well suited for the geometric study of PDE's with values ... More
Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functionsJul 28 2016Nov 18 2016I start by providing an updated summary of the penalized pixel-fitting (pPXF) method, which is used to extract the stellar and gas kinematics, as well as the stellar population of galaxies, via full spectrum fitting. I then focus on the problem of extracting ... More
Can classical physics agree with quantum physics on quantum phenomena?Apr 13 2015Classical physics fails where quantum physics prevails. This common understanding applies to quantum phenomena that are acknowledged to be beyond the reach of classical physics. Here, we make an attempt at weakening this solid belief that classical physics ... More
Implication of Sterile Fermions in Particle Physics and CosmologySep 22 2016The neutrino mass generation mechanism, the nature of dark matter and the origin of the baryon asymmetry of the Universe are three compelling questions that cannot be accounted for in the Standard Model of particle physics. In this thesis we focus on ... More
Production, storage and release of spin currents in quantum circuitsJul 18 2014Jul 23 2014Quantum rings connected to ballistic circuits couple strongly to external magnetic fields if the connection is not symmetric. By analytical theory and computer simulation I show that properly connected rings can be used to pump currents in the wires giving ... More
Metal abundances in the high-redshift intergalactic mediumDec 18 2013Twenty years of high-resolution spectroscopy at the 8-10 m class telescopes have drastically expanded our view of the gas-phase metallicity in the z>2 universe. This contribution briefly summarizes how these studies reveal a widespread metal pollution ... More
Nonlinear optical response of a two-dimensional atomic crystalOct 19 2015Dec 15 2015The theory of Bloembergen and Pershan for the light waves at the boundary of nonlinear media is extended to a nonlinear two-dimensional atomic crystal, i.e. a single planar atomic lattice, placed in between linear bulk media. The crystal is treated as ... More
Optimizations for Decision Making and Planning in Description Logic Dynamic Knowledge BasesFeb 16 2015May 04 2015Artifact-centric models for business processes recently raised a lot of attention, as they manage to combine structural (i.e. data related) with dynamical (i.e. process related) aspects in a seamless way. Many frameworks developed under this approach, ... More
A layman's note on a class of frequentist hypothesis testing problemsFeb 04 2015It is observed that for testing between simple hypotheses where the cost of Type I and Type II errors can be quantified, it is better to let the optimization choose the test size.
A remark on Einstein warped productsApr 22 2010Nov 24 2010We prove triviality results for Einstein warped products with non-compact bases. These extend previous work by D.-S. Kim and Y.-H. Kim. The proof, from the viewpoint of "quasi-Einstein manifolds" introduced by J. Case, Y.-S. Shu and G. Wei, rely on maximum ... More
Cyclotomic torsion points in elliptic schemesFeb 07 2018An elliptic curve defined over a number field possesses only a finite number of torsion points defined over the cyclotomic closure of its field of definition. In analogy to the relative version of the Manin-Mumford conjecture stated by Masser and Zannier, ... More
Electrolyte-gated organic synapse transistor interfaced with neuronsAug 03 2016We demonstrate an electrolyte-gated hybrid nanoparticle/organic synapstor (synapse-transistor, termed EGOS) that exhibits short-term plasticity as biological synapses. The response of EGOS makes it suitable to be interfaced with neurons: short-term plasticity ... More
The distance to NGC1316 (Fornax A): yet another curious caseFeb 28 2013Mar 18 2013The distance of NGC1316, the brightest galaxy in Fornax, is an interesting test for the cosmological distance scale. First, because Fornax is the 2nd largest cluster of galaxies at <~25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight ... More
A LISA Data-Analysis PrimerDec 03 2008Feb 20 2009This article is an introduction for the nonpractitioner to the ideas and issues of LISA data analysis, as reflected in the explorations and experiments of the participants in the Mock LISA Data Challenges. In particular, I discuss the methods and codes ... More
A Remark on the Convolution with Box SplinesMar 08 2010The semi-discrete convolution with the Box Spline is an important tool in approximation theory. We give a formula for the difference between semi-discrete convolution and convolution with the Box Spline. This formula involves multiple Bernoulli polynomials. ... More
Performance of the CDF Miniplug CalorimetersDec 16 2002Two Miniplug calorimeters, designed to measure the energy and lateral position of particles in the forward pseudorapidity region of 3.6<|\eta |<5.1, have been installed as part of the CDF upgraded detector for Run II at the Tevatron. Proton-antiproton ... More
Real space Renormalization Group analysis of a non-mean field spin-glassMay 25 2011Aug 23 2011A real space Renormalization Group approach is presented for a non-mean field spin-glass. This approach has been conceived in the effort to develop an alternative method to the Renormalization Group approaches based on the replica method. Indeed, non-perturbative ... More
The Out-of-Equilibrium Time-Dependent Gutzwiller ApproximationApr 10 2012We review the recently proposed extension of the Gutzwiller approximation, M. Schiro' and M. Fabrizio, Phys. Rev. Lett. 105, 076401 (2010), designed to describe the out-of-equilibrium time-evolution of a Gutzwiller-type variational wave function for correlated ... More
Exponential localization in one-dimensional quasiperiodic optical latticesJan 02 2009We investigate the localization properties of a one-dimensional bichromatic optical lattice in the tight binding regime, by discussing how exponentially localized states emerge upon changing the degree of commensurability. We also review the mapping onto ... More
On the UV dimensions of Loop Quantum GravityMay 19 2016Jul 28 2016Planck-scale dynamical dimensional reduction is attracting more and more interest in the quantum-gravity literature since it seems to be a model independent effect. However different studies base their results on different concepts of spacetime dimensionality. ... More
Anticipating Moves to Prevent Botnet Generated DDoS Flooding AttacksNov 30 2016Volumetric Distributed Denial of Service (DDoS) attacks have been a recurrent issue on the Internet. These attacks generate a flooding of fake network traffic to interfere with targeted servers or network links. Despite many efforts to detect and mitigate ... More
Analytic equivalence of geometric transitionsJul 25 2008Aug 28 2014In this paper \emph{analytic equivalence} of geometric transition is defined in such a way that equivalence classes of geometric transitions turn out to be the \emph{arrows} of the \cy web. Then it seems natural and useful, both from the mathematical ... More
On a remark by Y. NamikawaJul 25 2008Aug 28 2014The aim of the present paper is on the one hand to produce examples supporting the conclusion of Y. Namikawa in Remark 2.8 of \cite{N} and improving considerations of Example 1.11 of the same paper. On the other hand, it is intended to give a geometric ... More
The Renormalization Group for Disordered SystemsJul 25 2013In this thesis we investigate the Renormalization Group (RG) approach in finite-dimensional glassy systems, whose critical features are still not well-established, or simply unknown. We focus on spin and structural-glass models built on hierarchical lattices, ... More
Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functionsJul 28 2016I start by providing an updated summary of the penalized pixel-fitting (pPXF) method, which is used to extract the stellar and gas kinematics, as well as the stellar population of galaxies, via full spectrum fitting. I then focus on the problem of extracting ... More
Quantum Monte Carlo study of a two dimensional dipolar Bose gas in a harmonic trapMay 26 2013Apr 07 2014We present a Quantum Monte Carlo study of the ground state properties of a two dimensional system of Bose particle with dipole moment in a harmonic trap. The direction of the dipoles is assumed to be fixed by an external field. We study how the system ... More
Geometric Time Delay InterferometryApr 29 2005Jun 28 2005The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using Time Delay Interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser ... More
Poisson summation formula and Box splinesFeb 26 2013Mar 05 2013We generalize Dahmen-Micchelli deconvolution formula for Box splines with parameters. Our proof is based on identities for Poisson summation of rational functions with poles on hyperplanes.
Homological Type of Geometric TransitionsJan 04 2010Sep 19 2010The present paper gives an account and quantifies the change in topology induced by small and type II geometric transitions, by introducing the notion of the \emph{homological type} of a geometric transition. The obtained results agree with, and go further ... More
A rigidity theorem for small resolutionsMar 07 2012Aug 28 2014This paper presents a rigidity property of the exceptional locus of some kind of small birational contractions. An application in the context of geometric transitions and Calabi-Yau threefolds moduli space is then given, with some physical implication ... More
Accelerating the convergence of path integral dynamics with a generalized Langevin equationFeb 18 2012The quantum nature of nuclei plays an important role in the accurate modelling of light atoms such as hydrogen, but it is often neglected in simulations due to the high computational overhead involved. It has recently been shown that zero-point energy ... More
IDNet: Smartphone-based Gait Recognition with Convolutional Neural NetworksJun 10 2016Jun 15 2016Here, we present IDNet, an original user authentication framework from smartphone-acquired motion signals. Its goal is to recognize a target user from her/his way of walking, using the accelerometer and gyroscope (inertial) signals provided by a commercial ... More
Parameter estimation from Gravitational waves generated by non-spinning binary black holes with laser interferometers: beyond the Fisher informationApr 26 2010Nov 12 2010In this paper we apply to gravitational waves from non-spinning binary systems a recently intro- duced frequentist methodology to calculate analytically the error for a maximum likelihood estimate (MLE) of physical parameters. While existing literature ... More
An evolutionary model for simple ecosystemsJun 11 1999In this review some simple models of asexual populations evolving on smooth landscapes are studied. The basic model is based on a cellular automaton, which is analyzed here in the spatial mean-field limit. Firstly, the evolution on a fixed fitness landscape ... More
Competition in a Fitness LandscapeFeb 13 1997Aug 14 1997We present an extension of Eigen's model for quasi-species including the competition among individuals, proposed as the simplest mechanism for the formation of new species in a smooth fitness landscape. We are able to obtain analytically the critical ... More
Thermodynamics of the quantum butterfly effectSep 19 2016Sep 20 2016In this letter we consider the quantum analogue of the butterfly effect which is well known in the field of classical non-linear dynamics. Recently, it has been proposed to measure the effect using an out-of-time-order correlator (OTOC) between two local ... More
Mixed toric residues and tropical degenerationsOct 04 2004Oct 29 2005Building on our earlier work on toric residues and reduction, we give a proof for the mixed toric residue conejecture of Batyrev and Materov. We simplify and streamline our technique of tropical degenerations, which allows one to interpolate between two ... More
Quantum Quenches in the Hubbard Model: Time Dependent Mean Field Theory and The Role of Quantum FluctuationsFeb 08 2011Apr 18 2011We study the non equilibrium dynamics in the fermionic Hubbard model after a sudden change of the interaction strength. To this scope, we introduce a time dependent variational approach in the spirit of the Gutzwiller ansatz. At the saddle-point approximation, ... More
Real-Time Diagrammatic Monte Carlo for Nonequilibrium Quantum TransportAug 05 2008We propose a novel approach to nonequilibrium real-time dynamics of quantum impurities models coupled to biased non-interacting leads, such as those relevant to quantum transport in nanoscale molecular devices. The method is based on a Diagrammatic Monte ... More
On the Rabin signatureNov 10 2011Dec 17 2011Some Rabin signature schemes may be exposed to forgery; several variants are here described to counter this vulnerability. Blind Rabin signatures are also discussed.
Improvements on Cantor-Zassenhaus Factorization AlgorithmDec 23 2010May 27 2011After revisiting Cantor-Zassenhaus polynomial factorization algorithm, we describe a new simplified version of it, which requires less computational cost. Moreover we show that it is able to find a factor of a fully splitting polynomial of degree $t$ ... More
Categorical representability and intermediate Jacobians of Fano threefoldsMar 18 2011We define, basing upon semiorthogonal decompositions of $\Db(X)$, categorical representability of a projective variety $X$ and describe its relation with classical representabilities of the Chow ring. For complex threefolds satisfying both classical and ... More
(Un)detectable cluster structure in sparse networksNov 09 2007We study the problem of recovering a known cluster structure in a sparse network, also known as the planted partitioning problem, by means of statistical mechanics. We find a sharp transition from un-recoverable to recoverable structure as a function ... More
Replica bounds for optimization problems and diluted spin systemsAug 14 2002In this paper we generalize to the case of diluted spin models and random combinatorial optimization problems a technique recently introduced by Guerra (cond-mat/0205123) to prove that the replica method generates variational bounds for disordered systems. ... More
Topology of the ground state of two interacting Bose-Einstein condensatesFeb 20 2002We investigate the spatial patterns of the ground state of two interacting Bose-Einstein condensates. We consider the general case of two different atomic species (with different mass and in different hyperfine states) trapped in a magnetic potential ... More
Testing the Symmetrization Postulate on Molecules with Three Identical NucleiMar 24 2000We propose an experiment to look for possible small violations of the symmetrization postulate of Quantum Mechanics, in systems composed by three identical particles. Such violations could be detected by investigating the population of particular roto-vibrational ... More
Effects of confinement on thermal stability and folding kinetics in a simple Ising-like modelDec 06 2011Feb 08 2012In cellular environment, confinement and macromulecular crowding play an important role on thermal stability and folding kinetics of a protein. We have resorted to a generalized version of the Wako-Saito-Munoz-Eaton model for protein folding to study ... More
Preferential attachment in growing spatial networksNov 23 2010Nov 15 2011We obtain the degree distribution for a class of growing network models on flat and curved spaces. These models evolve by preferential attachment weighted by a function of the distance between nodes. The degree distribution of these models is similar ... More
Path Integral Approach to non-Markovian First-Passage Time ProblemsMay 04 2009The computation of the probability of the first-passage time through a given threshold of a stochastic process is a classic problem that appears in many branches of physics. When the stochastic dynamics is markovian, the probability admits elegant analytic ... More
Density Perturbations in String CosmologyMay 29 1997We discuss the generation and evolution of density perturbations during the large curvature phase of string cosmology. We find that perturbations in the scalar components of the metric evolve with cosmic time as $\exp (\gamma H_st)$ where $H_s$ is the ... More
Three-flavour neutrino oscillation update and comments on possible hints for a non-zero theta_{13}Dec 17 2008We provide a short summary of three-flavour neutrino oscillation parameters as determined from a global fit to 2008 data, and we comment on possible hints in favour of a non-zero value of the mixing angle theta_{13} found in arXiv:0806.2649. We do confirm ... More
On the meaning of logical completenessNov 07 2010Dec 22 2010Goedel's completeness theorem is concerned with provability, while Girard's theorem in ludics (as well as full completeness theorems in game semantics) are concerned with proofs. Our purpose is to look for a connection between these two disciplines. Following ... More
The Halo Mass Function from Excursion Set Theory. II. The Diffusing BarrierMar 06 2009Oct 21 2009In excursion set theory the computation of the halo mass function is mapped into a first-passage time process in the presence of a barrier, which in the spherical collapse model is a constant and in the ellipsoidal collapse model is a fixed function of ... More
Building Projected Entangled Pair States with a Local Gauge SymmetryNov 26 2015Apr 08 2016Tensor network states, and in particular projected entangled pair states (PEPS), suggest an innovative approach for the study of lattice gauge theories, both from a pure theoretic point of view, and as a tool for the analysis of the recent proposals for ... More