Results for "Alessandro Tomasi"

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Binary linear code weight distribution estimation by random bit stream compressionJun 06 2018A statistical estimation algorithm of the weight distribution of a linear code is shown, based on using its generator matrix as a compression function on random bit strings.
Colour image segmentation by the vector-valued Allen-Cahn phase-field model: a multigrid solutionOct 03 2007We propose a new method for the numerical solution of a PDE-driven model for colour image segmentation and give numerical examples of the results. The method combines the vector-valued Allen-Cahn phase field equation with initial data fitting terms. This ... More
Code generator matrices as RNG conditionersFeb 05 2015Mar 02 2017We quantify precisely the distribution of the output of a binary random number generator (RNG) after conditioning with a binary linear code generator matrix by showing the connection between the Walsh spectrum of the resulting random variable and the ... More
Code generator matrices as entropy extractorsFeb 05 2015We show the connection between the Walsh spectrum of the output of a binary random number generator (RNG) and the bias of individual bits, and use this to show how previously known bounds on the performance of linear binary codes as entropy extractors ... More
A weight-distribution bound for entropy extractors using linear binary codesMay 12 2014We consider a bound on the bias reduction of a random number generator by processing based on binary linear codes. We introduce a new bound on the total variation distance of the processed output based on the weight distribution of the code generated ... More
Latent Variable Time-varying Network InferenceFeb 12 2018Aug 02 2018In many applications of finance, biology and sociology, complex systems involve entities interacting with each other. These processes have the peculiarity of evolving over time and of comprising latent factors, which influence the system without being ... More
Two-tier blockchain timestamped notarization with incremental securityFeb 08 2019Digital notarization is one of the most promising services offered by modern blockchain-based solutions. We present a digital notary design with incremental security and cost reduced with respect to current solutions. A client of the service receives ... More
A Cesàro Average of Hardy-Littlewood numbersJun 01 2012Let $\Lambda$ be the von Mangoldt function and (r_{\textit{HL}}(n) = \sum_{m_1 + m_2^2 = n} \Lambda(m_1),) be the counting function for the Hardy-Littlewood numbers. Let $N$ be a sufficiently large integer. We prove that \sum_{n \le N} r_{\textit{HL}}(n) ... More
Sums of many primesJan 18 2011Assuming that the Generalized Riemann Hypothesis (GRH) holds, we prove an explicit formula for the number of representations of an integer as a sum of $k\geq 5$ primes. Our error terms in such a formula improve by some logarithmic factors an analogous ... More
A Diophantine problem with prime variablesJun 01 2012We study the distribution of the values of the form $\lambda_1 p_1 + \lambda_2 p_2 + \lambda_3 p_3^k$, where $\lambda_1$, $\lambda_2$ and $\lambda_3$ are non-zero real number not all of the same sign, with $\lambda_1 / \lambda_2$ irrational, and $p_1$, ... More
Short intervals asymptotic formulae for binary problems with prime powers, IIOct 26 2018We improve some results about the asymptotic formulae in short intervals for the average number of representations of integers of the forms $n=p_{1}^{\ell_1}+p_{2}^{\ell_2}$ and $n=p^{\ell_1} + m^{\ell_2}$, where $\ell_1, \ell_2\ge 2$ are fixed integers, ... More
Mean-field quantum dynamics for a mixture of Bose-Einstein condensatesMar 08 2016Sep 12 2016We study the effective time evolution of a large quantum system consisting of a mixture of different species of identical bosons in interaction. If the system is initially prepared so as to exhibit condensation in each component, we prove that condensation ... More
Cesàro average in short intervals for Goldbach numbersJun 02 2016We prove that a suitable explicit formula for the Cesaro-averaged number of representations of an integer as a sum of two primes holds in short intervals.
Effective non-linear spinor dynamics in a spin-1 Bose-Einstein condensateMar 14 2018Sep 03 2018We derive from first principles the experimentally observed effective dynamics of a spinor Bose gas initially prepared as a Bose-Einstein condensate and then left free to expand ballistically. In spinor condensates, which represent one of the recent frontiers ... More
Computing the Mertens and Meissel-Mertens constants for sums over arithmetic progressionsJun 11 2009We give explicit numerical values with 100 decimal digits for the Mertens constant involved in the asymptotic formula for $\sum\limits_{\substack{p\leq x p\equiv a \bmod{q}}}1/p$ and, as a by-product, for the Meissel-Mertens constant defined as $\sum_{p\equiv ... More
Short intervals asymptotic formulae for binary problems with prime powersJun 14 2018Jun 21 2018We prove results about the asymptotic formulae in short intervals for the average number of representations of integers of the forms $n=p_{1}^{\ell_1}+p_{2}^{\ell_2}$, with $\ell_1, \ell_2\in\{2,3\}$, $\ell_1+\ell_2\le 5$ are fixed integers, and $n=p^{\ell_1} ... More
On a ternary Diophantine problem with mixed powers of primesJun 01 2012Jul 30 2012Let $1 < k < 33 / 29$. We prove that if $\lambda_1$, $\lambda_2$ and $\lambda_3$ are non-zero real numbers, not all of the same sign and that $\lambda_1 / \lambda_2$ is irrational and $\varpi$ is any real number, then for any $\eps > 0$ the inequality ... More
A Diophantine problem with a prime and three squares of primesJun 01 2012We prove that if $\lambda_1$, $\lambda_2$, $\lambda_3$ and $\lambda_4$ are non-zero real numbers, not all of the same sign, $\lambda_1 / \lambda_2$ is irrational, and $\varpi$ is any real number then, for any $\eps > 0$ the inequality $ \bigl|\lambda_1 ... More
Blowdown of hydrocarbons pressure vessel with partial phase separationJan 05 2011We propose a model for the simulation of the blowdown of vessels containing two-phase (gas-liquid) hydrocarbon fluids, considering non equilibrium between phases. Two phases may be present either already at the beginning of the blowdown process (for instance ... More
A Cesàro Average of generalised Hardy-Littlewood numbersJun 13 2018Jan 04 2019We continue our recent work on additive problems with prime summands: we already studied the \emph{average} number of representations of an integer as a sum of two primes, and also considered individual integers. Furthermore, we dealt with representations ... More
Short-depth circuits for efficient expectation value estimationMay 20 2019The evaluation of expectation values $Tr\left[\rho O\right]$ for some pure state $\rho$ and Hermitian operator $O$ is of central importance in a variety of quantum algorithms. Near optimal techniques developed in the past require a number of measurements ... More
Gross-Pitaevskii non-linear dynamics for pseudo-spinor condensatesApr 01 2017Oct 18 2017We derive the equations for the non-linear effective dynamics of a so called pseudo-spinor Bose-Einstein condensate, which emerges from the linear many-body Schr\"odinger equation at the leading order in the number of particles. The considered system ... More
A Cesàro Average of Goldbach numbersJun 01 2012Let $\Lambda$ be the von Mangoldt function and (r_G(n) = \sum_{m_1 + m_2 = n} \Lambda(m_1) \Lambda(m_2)) be the counting function for the Goldbach numbers. Let $N \geq 2$ be an integer. We prove that &\sum_{n \le N} r_G(n) \frac{(1 - n/N)^k}{\Gamma(k ... More
Short intervals asymptotic formulae for binary problems with primes and powers, II: density $1$Apr 18 2015Nov 28 2015We prove that suitable asymptotic formulae in short intervals hold for the problems of representing an integer as a sum of a prime square and a square, or a prime square. Such results are obtained both assuming the Riemann Hypothesis and in the unconditional ... More
Short intervals asymptotic formulae for binary problems with primes and powers, I: density $3/2$Apr 09 2015Nov 28 2015We prove that suitable asymptotic formulae in short intervals hold for the problems of representing an integer as a sum of a prime and a square, or a prime square. Such results are obtained both assuming the Riemann Hypothesis and in the unconditional ... More
The number of Goldbach representations of an integerNov 14 2010We prove the following result: Let $N \geq 2$ and assume the Riemann Hypothesis (RH) holds. Then \[ \sum_{n=1}^{N} R(n) =\frac{N^{2}}{2} -2 \sum_{\rho} \frac{N^{\rho + 1}}{\rho (\rho + 1)} + O(N \log^{3}N), \] where $\rho=1/2+i\gamma$ runs over the non-trivial ... More
Sums of one prime power and two squares of primes in short intervalsJun 13 2018Let $k\ge 1$ be an integer. We prove that a suitable asymptotic formula for the average number of representations of integers $n=p_{1}^{k}+p_{2}^{2}+p_{3}^{2}$, where $p_1,p_2,p_3$ are prime numbers, holds in intervals shorter than the ones previously ... More
A Cesàro average for an additive problem with prime powersJun 13 2018Jun 21 2018In this paper we extend and improve our results on weighted averages for the number of representations of an integer as a sum of two powers of primes. Let $1\le \ell_1 \le \ell_2$ be two integers, $\Lambda$ be the von Mangoldt function and % \(r_{\ell_1,\ell_2}(n) ... More
Explicit relations between primes in short intervals and exponential sums over primesDec 22 2012Dec 29 2012Under the assumption of the Riemann Hypothesis (RH), we prove explicit quantitative relations between hypothetical error terms in the asymptotic formulae for truncated mean-square average of exponential sums over primes and in the mean-square of primes ... More
On the constant in the Mertens product for arithmetic progressions. I. IdentitiesJun 19 2007Sep 26 2008The aim of the paper is the proof of new identities for the constant in the Mertens product for arithmetic progressions. We deal with the problem of the numerical computation of these constants in another paper.
Hodge duality operators on left covariant exterior algebras over two and three dimensional quantum spheresDec 29 2011Jun 04 2012Using non canonical braidings, we first introduce a notion of symmetric tensors and corresponding Hodge operators on a class of left covariant 3d differential calculi over the quantum SU(2) group, then we induce Hodge operators on the left covariant 2d ... More
Free fall and self-force: an historical perspectiveMay 04 2010Free fall has signed the greatest markings in the history of physics through the leaning Pisa tower, the Cambridge apple tree and the Einstein lift. The perspectives offered by the capture of stars by supermassive black holes are to be cherished, because ... More
Ground state energy of the low density Hubbard model. An upper boundNov 14 2006May 04 2007We derive an upper bound on the ground state energy of the three-dimensional (3D) repulsive Hubbard model on the cubic lattice agreeing in the low density limit with the known asymptotic expression of the ground state energy of the dilute Fermi gas in ... More
Time-reversal odd distribution functions in chiral models with vector mesonsJan 30 2005The so-called time-reversal odd distribution functions are known to be non-vanishing in QCD due to the presence of the link operator in the definition of these quantities. I show that T-odd distributions can be non-vanishing also in chiral models, if ... More
Models for transverse-momentum distributions and transversityNov 28 2011I present a short review of models for transverse-momentum distributions and transversity, with a particular attention on general features common to many models. I compare some model results with experimental extractions. I discuss the existence of relations ... More
GLACIER and related R&DJul 05 2011Liquid argon detectors, with mass up to 100 kton, are being actively studied in the context of proton decay searches, neutrino astrophysics and for the next generation of long baseline neutrino oscillation experiments to study the neutrino mass hierarchy ... More
Variational approximations for stationary states of Ising-like modelsJul 25 2013We introduce a new variational approach to the stationary state of kinetic Ising-like models. The approach is based on the cluster expansion of the entropy term appearing in a functional which is minimized by the system history. We rederive a known mean-field ... More
Deriving exact results for Ising-like models from the cluster variation methodSep 24 1999The cluster variation method (CVM) is an approximation technique which generalizes the mean field approximation and has been widely applied in the last decades, mainly for finding accurate phase diagrams of Ising-like lattice models. Here we discuss in ... More
Applications of some exponential sums on prime powers: a surveyJun 02 2016A survey paper on some recent results on additive problems with prime powers.
A Formal Framework for Modeling Trust and Reputation in Collective Adaptive SystemsJul 08 2016Trust and reputation models for distributed, collaborative systems have been studied and applied in several domains, in order to stimulate cooperation while preventing selfish and malicious behaviors. Nonetheless, such models have received less attention ... More
Many Haken Heegaard splittingsOct 31 2016We give a simple criterion for a Heegaard splitting to yield a Haken manifold. As a consequence, we construct many Haken manifolds, in particular homology spheres, with prescribed properties, namely Heegaard genus, Heegaard distance and Casson invariant. ... More
Hilbert++ ManualJun 28 2007Mar 01 2009We present here an installation guide, a hand-on mini-tutorial through examples, and the theoretical foundations of the Hilbert++ code.
Operation and calibration of the Silicon Drift Detectors of the ALICE experiment during the 2008 cosmic ray data taking periodJan 18 2010The calibration and performance of the Silicon Drift Detector of the ALICE experiment during the 2008 cosmic ray run will be presented. In particular the procedures to monitor the running parameters (baselines, noise, drift speed) are detailed. Other ... More
Towards the Modeling of Behavioral Trajectories of Users in Online Social MediaNov 17 2016In this paper, we introduce a methodology that allows to model behavioral trajectories of users in online social media. First, we illustrate how to leverage the probabilistic framework provided by Hidden Markov Models (HMMs) to represent users by embedding ... More
Implications of first LHC resultsJul 06 2011We discuss implications of first LHC results for models motivated by the hierarchy problem: large extra dimensions and supersymmetry. We present bounds, global fits and implications for naturalness.
The fine-tuning price of the early LHCJan 11 2011Jul 26 2011LHC already probed and excluded half of the parameter space of the Constrained Minimal Supersymmetric Standard Model allowed by previous experiments. Only about 0.3% of the CMSSM parameter space survives. This fraction rises to about 0.9% if the bound ... More
Radiatively induced light right-handed stopSep 08 1996Sep 10 1996A right-handed stop not much heavier or even lighter than the Z boson has today desirable phenomenological consequences. We study how it can result within the usual radiative scenario of electroweak symmetry breaking. A restriction on the gaugino mass ... More
Interpreting the 750 GeV digamma excess: a reviewMay 30 2016Aug 05 2016We summarise the main experimental, phenomenological and theoretical issues related to the 750 GeV digamma excess
The world underground scientific facilities. A compendiumDec 07 2007Underground laboratories provide the low radioactive background environment necessary to explore the highest energy scales that cannot be reached with accelerators, by searching for extremely rare phenomena. I have requested to the Directors of the Laboratories ... More
Controllability of bilinear quantum systems in explicit times via explicit control fieldsMay 09 2017Feb 07 2019We consider the bilinear Schroedinger equation on a bounded one-dimensional domain and we provide explicit times such that the global exact controllability is verified. In addition, we show how to construct controls for the global approximate controllability. ... More
Apolar Ideal and Normal Bundle of Rational CurvesMar 22 2012As in our previous work [1] we address the problem to determine the splitting of the normal bundle of rational curves. With apolarity theory we are able to characterize some particular subvarieties in some Hilbert scheme of rational curves, defined by ... More
On Farber sequences in locally compact groupsDec 12 2018We will prove that any sequence of lattices in a fixed locally compact group which satisfy the conclusion of the Stuck-Zimmer theorem is Farber.
Asymptotic invariants of lattices in locally compact groupsDec 05 2018The aim of this work is to understand some of the asymptotic properties of sequences of lattices in a fixed locally compact group. In particular we will study the asymptotic growth of the Betti numbers of the lattices renormalized by the covolume and ... More
H2 chemistry in galaxy simulations: an improved supernova feedback modelAug 30 2018Jan 18 2019In this study, we present and validate a variation of recently-developed physically motivated sub-grid prescriptions for supernova feedback that account for the unresolved energy-conserving phase of the bubble expansion. Our model builds upon the implementation ... More
Decay estimates for the linear damped wave equation on the Heisenberg groupAug 07 2019This paper is devoted to the derivation of $L^2$ - $L^2$ decay estimates for the solution of the homogeneous linear damped wave equation on the Heisenberg group $\mathbf{H}_n$, for its time derivative and for its horizontal gradient. Moreover, we consider ... More
A $K$-theoretical invariant and bifurcation for a parameterized family of functionalsMay 24 2009Jul 24 2013For a family of functionals defined on a Hilbert manifold and smoothly depending on a compact finite dimensional manifold, we give a sufficient condition on the parameter space in such a way the family bifurcate from the trivial branch.
An introduction to universality and renormalization group techniquesOct 08 2012Jun 25 2013These lecture notes have been written for a short introductory course on universality and renormalization group techniques given at the VIII Modave School in Mathematical Physics by the author, intended for PhD students and researchers new to these topics. ... More
A Jarník-type theorem for a problem of approximation by cubic polynomialsSep 25 2018For a given decreasing positive real function $\psi$, let $\mathcal{A}_n(\psi)$ be the set of real numbers for which there are infinitely many integer polynomials $P$ of degree up to $n$ such that $\left\lvert P(x) \right\rvert \leq \psi(\operatorname{H}(P))$. ... More
Global existence of solutions for semi-linear wave equation with scale-invariant damping and mass in exponentially weighted spacesAug 02 2017In this paper we consider the following Cauchy problem for the semi-linear wave equation with scale-invariant dissipation and mass and power non-linearity: \begin{align}\label{CP abstract} \begin{cases} u_{tt}-\Delta u+\dfrac{\mu_1}{1+t} u_t+\dfrac{\mu_2^2}{(1+t)^2}u=|u|^p, ... More
Bistable reaction equations with doubly nonlinear diffusionJul 05 2017Jan 11 2019Reaction-diffusion equations appear in biology and chemistry, and combine linear diffusion with different kind of reaction terms. Some of them are remarkable from the mathematical point of view, since they admit families of travelling waves that describe ... More
Effective and Big Divisors on a Projective Symmetric VarietyJun 29 2009May 03 2010We describe the effective and the big cones of a projective symmetric variety. Moreover, we give a necessary and sufficient combinatorial criterion for the bigness of a nef divisor on a projective symmetric variety. When the variety is toroidal and the ... More
Geometrical description of smooth projective symmetric varieties with Picard number oneDec 11 2008In a previous paper we have classified the smooth projective symmetric G-varieties with Picard number one (and G semisimple). In this work we give a geometrical description of such varieties. In particular, we determine their group of automorphisms. When ... More
Clustering Strategies for Multicast Precoding in Multi-Beam Satellite SystemsApr 11 2018Jan 28 2019Next generation multi-beam SatCom architectures will heavily exploit full frequency reuse schemes along with interference management techniques, e.g., precoding or multiuser detection, to drastically increase the system throughput. In this framework, ... More
Quasi-convexity of hyperbolically embedded subgroupsOct 29 2013We show that any infinite order element $g$ of a virtually cyclic hyperbolically embedded subgroup of a group $G$ is Morse, that is to say any quasi-geodesic connecting points in the cyclic group $C$ generated by $g$ stays close to $C$. This answers a ... More
Laplacians and gauged Laplacians on a quantum Hopf bundleMar 29 2010This paper presents an analysis of the set of connections and covariant derivatives on a U(1) quantum Hopf bundle on the standard Podles sphere, whose total space quantum SU(2) is equipped with the 3d left covariant differential calculus by Woronowicz. ... More
Steinitz classes of tamely ramified nonabelian extensions of odd prime power orderJan 19 2010The Steinitz class of a number field extension K/k is an ideal class in the ring of integers O_k of k, which, together with the degree [K:k] of the extension determines the O_k-module structure of O_K. We call R_t(k,G) the classes which are Steinitz classes ... More
Neutron Stars, Supernova Explosions and the Transition to Quark MatterApr 09 1999The transition to quark matter can take place in neutron stars. The structure of a hybrid star, containing a core made of quark matter is discussed. The maximum mass of the non-rotating hybrid star turns out to be 1.6 M_s. Possible signatures of the quark ... More
Trends in Fast Feedback R&DJun 11 2008In this paper, starting from the basic description of the equation that governs the bunch motion and looking at the advances of the technology, three examples of feedback designs versus technology trend are presented and discussed. In particular the author ... More
The nematic phase of a system of long hard rods - ICMP12 talk, Aalborg, August 2012Sep 13 2012In this talk I consider a two-dimensional lattice model for liquid crystals consisting of long rods interacting via purely hard core interactions, with two allowed orientations defined by the underlying lattice. I report a rigorous proof of the existence ... More
On the low-temperature phase of the three-state antiferromagnetic Potts model on the simple cubic latticeNov 25 1996The three-state antiferromagnetic Potts model on the simple cubic lattice is investigated using the cluster variation method in the cube and the star-cube approximations. The broken-sublattice-symmetry phase is found to be stable in the whole low-temperature ... More
Single-spin asymmetries and Qiu-Sterman effect(s)Nov 08 2005Nov 15 2005I discuss the relation between the Qiu-Sterman effects on one hand and the Collins, Sivers and Boer-Mulders effects on the other hand. It was suggested before that some of these effects are in fact the same, thus providing interesting connections between ... More
Quantum black holes and holographyDec 15 2005It is technically difficult (if not impossible) to write down and solve self-consistently the semiclassical Einstein equations in the case of evaporating black holes. These difficulties can in principle be overcome in an apparently very different context, ... More
Generalized belief propagation for the magnetization of the simple cubic Ising modelJan 16 2014A new approximation of the cluster variational method is introduced for the three-dimensional Ising model on the simple cubic lattice. The maximal cluster is, as far as we know, the largest ever used in this method. A message-passing algorithm, generalized ... More
On the Integrable Structure of the Ising ModelOct 23 2007Oct 31 2007Starting from the lattice $A_3$ realization of the Ising model defined on a strip with integrable boundary conditions, the exact spectrum (including excited states) of all the local integrals of motion is derived in the continuum limit by means of TBA ... More
Mass and temperature limits for blackbody radiationMar 24 2006A spherically symmetric distribution of classical blackbody radiation is considered, at conditions in which gravitational self-interaction effects become not negligible. Static solutions to Einstein field equations are searched for, for each choice of ... More
A semiclassical approach to η/s bound through holographyOct 05 2009We consider the holographic principle, in its lightsheet formulation, in the semiclassical context of statistical-mechanical systems in classical Einstein spacetimes. A local condition, in terms of entropy and energy local densities of the material medium ... More
New Constraints on Dark EnergyJun 29 2004Jun 30 2004New Cosmic Microwave Background, Galaxy Clustering and Supernovae type Ia data are increasingly constraining the dark energy component of our Universe. While the cosmological constant scenario remains consistent with these new tight constraints, the data ... More
Is psychosis caused by defective dissociation? An Artificial Life model for schizophreniaOct 11 2016Both neurobiological and environmental factors are known to play a role in the origin of schizophrenia, but no model has been proposed that accounts for both. This work presents a functional model of schizophrenia that merges psychodynamic elements with ... More
On the statistical properties of viral misinformation in online social mediaSep 29 2016The massive diffusion of online social media allows for the rapid and uncontrolled spreading of conspiracy theories, hoaxes, unsubstantiated claims, and false news. Such an impressive amount of misinformation can influence policy preferences and encourage ... More
Beams of particles and papers. How digital preprint archives shape authorship and creditFeb 27 2016Jun 23 2016In high energy physics, scholarly papers circulate primarily through online preprint archives based on a centralized repository, arXiv, that physicists simply refer to as "the archive". This is not just a tool for preservation and memory, but also a space ... More
Bose particles in a box II. A convergent expansion of the ground state of the Bogoliubov Hamiltonian in the mean field limiting regimeNov 22 2015May 19 2016In this paper we consider an interacting Bose gas at zero temperature, in a finite box and in the mean field limiting regime. The N gas particles interact through a pair potential of positive type and with an ultraviolet cut-off. Its (nonzero) Fourier ... More
Bose particles in a box I. A convergent expansion of the ground state of a three-modes Bogoliubov HamiltonianNov 22 2015Sep 16 2016In this paper we introduce a novel multi-scale technique to study many-body quantum systems where the total number of particles is kept fixed. The method is based on Feshbach map and the scales are represented by occupation numbers of particle states. ... More
A comparison between the Bergman and Szegő kernels of the non-smooth worm domain $D'_β$May 09 2015Nov 30 2015In this work we provide an asymptotic expansion for the Szeg\H{o} kernel associated to a suitably defined Hardy space on the the non-smooth worm domain $D'_\beta$. After describing the singularities of the kernel, we compare it with an asymptotic expansion ... More
Speeding up lower bound estimation in powerlaw distributionsMar 17 2015The traditional lower bound estimation method for powerlaw distributions based on the Kolmogorov-Smirnov distance proved to perform better than other competing methods. However, if applied to very large collections of data, such a method can be computationally ... More
Breaking the symmetries in self-induced flavor conversions of neutrino beams from a ringJun 22 2015Oct 29 2015Self-induced flavor conversions of supernova (SN) neutrinos have been characterized in the spherically symmetric "bulb" model, reducing the neutrino evolution to a one dimensional problem along a radial direction. We lift this assumption, presenting a ... More
Ground state and excitation spectra of a strongly correlated lattice by the coupled cluster methodFeb 16 2012Mar 19 2012We apply Coupled Cluster Method to a strongly correlated lattice and develop the Spectral Coupled Cluster equations by finding an approximation to the resolvent operator, that gives the spectral response for an certain class of probe operators. We apply ... More
Explaining the magnetic moment reduction of Fullerene encapsulated Gadolinium through a theoretical modelNov 01 2004We propose a Theoretical model accounting for the recently observed reduced magnetic moment of Gadolinium in fullerenes. While this reduction has been observed also for other trivalent rare-hearth atoms (Dy3+, Er3+, Ho3+) in fullerenes and can be ascribed ... More
QCD in the Regge limit: from gluon Reggeization to physical amplitudesJan 23 2006Jan 25 2006This paper is a brief survey of the Balitskii-Fadin-Kuraev-Lipatov (BFKL) approach for the description of hard or semi-hard processes in the so-called Regge limit of perturbative QCD. The starting point is a fundamental property of perturbative QCD, the ... More
Computer Simulation of Quantum Dynamics in a Classical Spin EnvironmentApr 24 2014In this paper a formalism for studying the dynamics of quantum systems coupled to classical spin environments is reviewed. The theory is based on generalized antisymmetric brackets and naturally predicts open-path off-diagonal geometric phases in the ... More
Searches for sterile neutrinos (and other light particles)Jul 12 2004Future neutrino and cosmological experiments will perform powerful searches for new light particles. After a general introduction we discuss how a new light fermion (`sterile neutrino') could manifest.
Universal aspects in the equation of state for Yang-Mills theoriesOct 05 2015We present high-precision lattice calculations of the thermodynamics of Yang-Mills theories with different gauge groups. In the confining phase, we show that the equation of state is described remarkably well by a gas of massive, non-interacting glueballs, ... More
A new indexed approach to render the attractors of Kleinian groupsSep 23 2017One widespread procedure to render the attractor of Kleinian groups, published in the renown book "Indra's Pearls" and based upon a combinatorial tree model, wants huge memory resources to compute and store all the words required. We will present here ... More
Bose particles in a box III. A convergent expansion of the ground state of the Hamiltonian in the mean field limiting regimeNov 22 2015May 19 2016In this paper we consider an interacting Bose gas at zero temperature, constrained to a finite box and in the mean field limiting regime. The N gas particles interact through a pair potential of positive type and with an ultraviolet cut-off. The (nonzero) ... More
The unirationality of the moduli space of curves of genus $\leq 14$Feb 03 2004The new result is the unirationality of the moduli space of curves of genus 14. The method applies to lower genus.
Quantum BiologyJul 11 2009A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched ... More
Ambrosio-Tortorelli Approximation of Quasi-Static Evolution of Brittle FracturesMar 04 2003We define a notion of quasi-static evolution for the elliptic approximation of the Mumford-Shah functional proposed by Ambrosio and Tortorelli. Then we prove that this regular evolution converges to a quasi-static growth of brittle fractures in linearly ... More
Quantum metric for null separated events and spacetime atomsDec 04 2018Mar 13 2019Recently, a proposal has been made to figure out the expected discrete nature of spacetime at the smallest scales in terms of atoms of spacetime, capturing their effects through a scalar $\rho$, related to their density, function of the point $P$ and ... More
A retrospective look at Regge polesJul 06 2018The theoretical motivations that led Tullio Regge to investigate the analytical properties of the scattering amplitude of the collision process between two particles in terms of complex energy and complex angular momentum are briefly reviewed and set ... More
On the Waring-Goldbach problem on averageJun 15 2018Jan 21 2019Let $s$, $\ell$ be two integers such that $2\le s\le \ell-1$, $\ell\ge 3$. We prove that a suitable asymptotic formula for the average number of representations of integers $n=\sum_{i=1}^{s} p_{i}^{\ell}$, where $p_i$, $i=1,\dotsc,s$, are prime numbers, ... More
On a Transform Method for the Efficient Computation of Conditional VaR (and VaR) with Application to Loss Models with Jumps and Stochastic VolatilityJul 03 2014In this paper we consider Fourier transform techniques to efficiently compute the Value-at-Risk and the Conditional Value-at-Risk of an arbitrary loss random variable, characterized by having a computable generalized characteristic function. We exploit ... More