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 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
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
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
Sum of one prime and two squares of primes in short intervalsJun 13 2014Jul 30 2015Assuming the Riemann Hypothesis we prove that the interval $[N, N + H]$ contains an integer which is a sum of a prime and two squares of primes provided that $H \ge C (\log N)^{4}$, where $C > 0$ is an effective constant.
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
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.
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
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 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
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
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
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.
A Diophantine approximation problem with two primes and one $k$-th power of a primeMay 31 2017Feb 13 2018We refine a result of the last two Authors of [8] on a Diophantine approximation problem with two primes and a $k$-th power of a prime which was only proved to hold for $1<k<4/3$. We improve the $k$-range to $1<k\le 3$ by combining Harman's technique ... More
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
Bubble propagation in a helicoidal molecular chainJul 26 2000We study the propagation of very large amplitude localized excitations in a model of DNA that takes explicitly into account the helicoidal structure. These excitations represent the ``transcription bubble'', where the hydrogen bonds between complementary ... More
On a Rigorous Proof of the Joos-Zeh Formula for Decoherence in a Two-Body ProblemJul 30 2003We consider a simple one dimensional system consisting of two particles interacting with a $\delta$-potential and we discuss a rigorous derivation of the asymptotic wave function of the system in the limit of small mass ratio. We apply the result to the ... More
Geometry of non-compact minimal and marginally outer-trapped surfaces in asymptotically flat manifoldsOct 18 2013Apr 07 2014In this article we extend several foundational results of the theory of complete minimal surfaces of finite index in the Euclidean space to minimal surfaces in asymptotically flat manifolds and, more generally, to marginally outer-trapped surfaces in ... 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
Quaternionic regularity and the dibar-Neumann problem in C^2Dec 04 2006Dec 13 2006Let D be a domain in the quaternionic space H. We prove a differential criterion that characterizes Fueter-regular quaternionic functions f:bD -> H of class C^1. We find differential operators T and N, with complex coefficients, such that a function f ... 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
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
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
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
On the decomposition numbers of $\mathrm{SO}_8^+(2^f)$Oct 16 2017Let $q=2^f$, and let $G=\mathrm{SO}_8^+(q)$ and $U$ be a Sylow $2$-subgroup of $G$. We first describe the fusion of the conjugacy classes of $U$ in $G$. We then use this information to prove the unitriangularity of the $\ell$-decomposition matrices of ... 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.
Review of AdS/CFT Integrability, Chapter VI.2: Yangian AlgebraDec 17 2010Nov 07 2011We review the study of Hopf algebras, classical and quantum R-matrices, infinite-dimensional Yangian symmetries and their representations in the context of integrability for the N=4 vs AdS5xS5 correspondence.
Universal Enveloping Algebras of PBW TypeAug 26 2010Dec 23 2010We continue our investigation of the general notion of universal enveloping algebra introduced in [A. Ardizzoni, \emph{A Milnor-Moore Type Theorem for Primitively Generated Braided Bialgebras}, J. Algebra \textbf{327} (2011), no. 1, 337--365]. Namely ... 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
Polycomp: efficient and configurable compression of astronomical timelinesApr 27 2016This paper describes the implementation of polycomp, a open-sourced, publicly available program for compressing one-dimensional data series in tabular format. The program is particularly suited for compressing smooth, noiseless streams of data like pointing ... More
Positive operator measures, generalised imprimitivity theorem, and their applicationsMay 30 2005Given a topological group $G$ and a unitary representation $U$ of $G$, we consider the problem of classifying the positive operator measures which are based on a $G$-homogeneous space $X$ and covariant with respect to the representation $U$. We completely ... More
Order Parameter for the Transition from Phase to Amplitude TurbulenceAug 06 1996The maximal conserved phase gradient is introduced as an order parameter to characterize the transition from phase- to defect-turbulence in the complex Ginzburg-Landau equation. It has a finite value in the phase-turbulent regime and decreases to zero ... More
Ab initio calculations on nuclear matter properties including the effects of three-nucleons interactionOct 01 2012In this thesis, the ground state properties of nuclear matter, namely the energy per particle and the response to weak probes, are computed, studying the effects of three nucleon interactions. Both the variational approach, based on the formalism of correlated ... More
Thermal production of axino Dark MatterMar 30 2010Jun 24 2010We reconsider thermal production of axinos in the early universe, adding: a) missed terms in the axino interaction; b) production via gluon decays kinematically allowed by thermal masses; c) a precise modeling of reheating. We find an axino abunance a ... More
Theory summary of Moriond Electro-Weak 2015Apr 30 2015I summarise the theoretical talks at Moriond 2015, with emphasis on naturalness.
Naturalness of supersymmetric modelsApr 06 1999After presenting a simple procedure for testing naturalness (similar to Bayesian inference and not more subjective than it) we show that LEP2 experiments pose a naturalness problem for `conventional' supersymmetric models. About 95% of the parameter space ... More
Resonant Activation in Asymmetric PotentialsMay 15 2008Oct 23 2008The resonant activation effect (RA) has been well studied in different ways during the last two decades. It consists in the presence of a minimum in the mean time spent by a Brownian particle to exit from a potential well in the presence of a fluctuating ... More
Multi-azimuthal-angle effects in self-induced supernova neutrino flavor conversions without axial symmetryAug 06 2013Oct 16 2013The flavor evolution of neutrinos emitted by a supernova (SN) core is strongly affected by the refractive effects associated with the neutrino-neutrino interactions in the deepest stellar regions. Till now, all numerical studies have assumed the axial ... More
Finite Size Corrections for DimersAug 10 2012In this paper we derive the finite size corrections to the energy eigenvalues of the energy for 2D dimers on a square lattice. These finite size corrections, as in the case of Critical Dense Polymers, are proportional to the eigenvalues of the Local Integrals ... More
Cosmology Rounding the CapeApr 16 2002A survey is made of the present observational status on cosmological parameters from microwave background anisotropies. I then move to some non-standard aspect of parameter extraction like quintessence, extra-background of relativistic particles and variations ... More
Gravitational recoil in nonspinning black hole binaries: the span of test-mass resultsJun 26 2013Dec 16 2013We consider binary systems of coalescing, nonspinning, black holes of masses $m_{1}$ and $m_{2}$ and show that the gravitational recoil velocity for any mass ratio can be obtained accurately by extrapolating the waveform of the test-mass limit case. The ... More
A proof of the Bekenstein bound for any strength of gravity through holographyMar 02 2009Jul 09 2010The universal entropy bound of Bekenstein is considered, at any strength of the gravitational interaction. A proof of it is given, provided the considered general-relativistic spacetimes allow for a meaningful and inequivocal definition of the quantities ... More
A note on the connection between the universal relaxation bound and the covariant entropy boundJul 02 2008Jun 24 2009A recently proposed universal lower-bound to the characteristic relaxation times of perturbed thermodynamic systems, derived from quantum information theory and (classical) thermodynamics and known to be saturated for (certain) black holes, is investigated ... More
On the statistical-mechanical meaning of the Bousso boundMar 18 2008Jun 04 2008The Bousso entropy bound, in its generalized form, is investigated for the case of perfect fluids at local thermodynamic equilibrium and evidence is found that the bound is satisfied if and only if a certain local thermodynamic property holds, emerging ... More
From Unruh temperature to generalized Bousso boundAug 28 2007Nov 28 2007In a classical spacetime satisfying Einstein's equation and the null convergence condition, the same quantum mechanical effects that cause black holes to have a temperature are found to imply, if joined to the macroscopic nature of entropy, the covariant ... More
(A class of) Hodge duality operators over the quantum SU(2)Apr 03 2011Oct 03 2012On the exterior algebra over the quantum SU(2) coming from the four dimensional bicovariant calculus \`a la Woronowicz we introduce, using sesquilinear contraction maps, a class of metrics and Hodge duality operators, and compare this formulation with ... More
Applications of the Weyl-Wigner formalism to noncommutative geometryMay 31 2005In this dissertation the Weyl-Wigner approach is presented as a map between functions on a real cartesian symplectic vector space and a set of operators on a Hilbert space, to analyse some aspects of the relations between quantum and classical formalism, ... More
Separable and tree-like asymptotic cones of groupsOct 06 2010Mar 06 2011Using methods from nonstandard analysis, we will discuss which metric spaces can be realized as asymptotic cones. Applying the results we will find in the context of groups, we will prove that a group with "a few" separable asymptotic cones is virtually ... More
Steinitz classes of tamely ramified Galois extensions of algebraic number fieldsOct 27 2009The 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 rt(k,G) the classes which are Steinitz classes ... More
Dynamical evolution of planetary systemsJun 21 2011The apparent regularity of the motion of the giant planets of our solar system suggested for decades that said planets formed onto orbits similar to the current ones and that nothing dramatic ever happened during their lifetime. The discovery of extra-solar ... More
Cluster variation - Pade` approximants method for the simple cubic Ising modelOct 20 1999Jun 06 2000The cluster variation - Pade` approximant method is a recently proposed tool, based on the extrapolation of low/high temperature results obtained with the cluster variation method, for the determination of critical parameters in Ising-like models. Here ... More
Transverse-momentum-dependent parton distributions (TMDs)Dec 10 2010Transverse-momentum-dependent parton distributions (TMDs) provide three-dimensional images of the partonic structure of the nucleon in momentum space. We made impressive progress in understanding TMDs, both from the theoretical and experimental point ... More
What can we learn from TMD measurements?Feb 16 2009Transverse-momentum-dependent parton distribution and fragmentation functions describe the partonic structure of the nucleon in a three-dimensional momentum space. They are subjects of flourishing theoretical and experimental activity. They provide novel ... More
The analog of the Hawking effect in BECsNov 28 2014The observation of the Hawking effect from black holes in the astrophysical context is unlikely. However, the analog of this effect is present in condensed matter systems. We focus on Bose-Einstein condensates, and on a proposal to detect it through correlation ... More
Generic finiteness of minimal surfaces with bounded Morse indexSep 23 2015Jun 13 2016Given a compact 3-manifold N without boundary, we prove that for a bumpy metric of positive scalar curvature the space of minimal surfaces having a uniform upper bound on the Morse index is always finite unless the manifold itself contains an embedded ... More
Ultraproducts, weak equivalence and sofic entropySep 10 2015In this work, we study pmp actions of countable groups on arbitrary diffuse probability spaces under the point of view of weak equivalence. We will show that any such an action is weakly equivalent to an action on a standard probability space. We also ... More
Statistical Mechanics of Quantum-Classical Systems with Holonomic ConstraintsNov 15 2005The statistical mechanics of quantum-classical systems with holonomic constraints is formulated rigorously by unifying the classical Dirac bracket and the quantum-classical bracket in matrix form. The resulting Dirac quantum-classical theory, which conserves ... More
On the universal abelian variety of dimension 4Nov 25 2007Aug 08 2008Let A be the moduli space of principally polarized abelian varieties of dimension 4 over an algebraically closed field k of characteristic different from 2,3. It is proved that the universal principally polarized abelian variety over A, as well as the ... More
Holomorphic functions and regular quaternionic functions on the hyperkähler space HNov 28 2007Let H be the space of quaternions, with its standard hypercomplex structure. Let R(D) be the module of regular functions on D. For every unitary vector p in S^2, R(D) contains the space of holomorphic functions w.r.t. the complex structure J_p induced ... More
Linear Collisionless Landau Damping in Hilbert SpaceDec 16 2014The equivalence between the Laplace transform [Landau L., J. Phys. USSR, 10 (1946), 25] and Hermite transform [Zocco and Schekochihin, Phys. Plasmas, 18, 102309 (2011)] solutions of the linear collisionless Landau damping problem is proven.
On a solution to display non-filled-in quaternionic Julia setsAug 01 2006Aug 01 2006During early 1980s, the so-called `escape time' method, developed to display the Julia sets for complex dynamical systems, was exported to quaternions in order to draw analogous pictures in this wider numerical field. Despite of the fine results in the ... More
Playing with the critical point. An experiment with the Mandelbrot set connectivityAug 15 2006By means of a graphical journey across the Mandelbrot set for the classic quadratic iterator $f(z):z^2+q$, we illustrate how connectivity breaks as the seed $z_0$ is no longer at the critical point of $f(z)$. Finally we suggest an attack to the MLC conjecture. ... More
Néron models of $Pic^0$ via $Pic^0$Sep 22 2015We provide a new description of the N\'eron model of the Jacobian of a smooth curve $C_K$ with stable reduction $C_R$ on a discrete valuation ring $R$ with field of fractions $K$. Instead of the regular semistable model, our approach uses the regular ... More
Special Lagrangian Geometry in irreducible symplectic 4-foldsJan 11 2000Having fixed a Kaehler class and the unique corresponding hyperkaehler metric, we prove that all special Lagrangian submanifolds of an irreducible symplectic 4-fold X are bi-Lagrangian and that they are obtained by complex submanifolds via a sort of "hyperkaehler ... More
A note on the computation of the Euler-Kronecker constants for cyclotomic fieldsMar 13 2019Mar 22 2019The goal of this note is to introduce an alternative method to compute the Euler-Kronecker constants for cyclotomic fields and to compare it with other two different ways of computing the same quantity. The new algorithm requires the values of the generalised ... More
Normal projectivity of complete symmetric varietiesMay 16 2006Chiriv\`{\i} and Maffei \cite{CM II} have proved that the multiplication of sections of any two ample spherical line bundles on the wonderful symmetric variety $X=\bar{G/H}$ is surjective. We have proved two criterions that allows ourselves to reduce ... More
The Selberg integral and a new pair-correlation function for the zeros of the Riemann zeta-functionMar 09 2016The present paper is a report on joint work with Alessandro Languasco and Alberto Perelli on our recent investigations on the Selberg integral and its connections to Montgomery's pair-correlation function. We introduce a more general form of the Selberg ... More
On Whitney numbers of the Order Ideals of Generalized Fences and CrownsMay 30 2005Jun 17 2005We solve some recurrences given by E. Munarini and N. Zagaglia Salvi proving explicit closed formulas for Whitney numbers of the distributive lattices of order ideals of the fence poset and crown poset. Moreover, we get explicit closed formulas for Whitney ... More
Asymptotic analysis for radial sign-changing solutions of the Brezis-Nirenberg problemDec 20 2013We study the asymptotic behavior, as $\lambda \rightarrow 0$, of least energy radial sign-changing solutions $u_\lambda$, of the Brezis-Nirenberg problem \begin{equation*} \begin{cases} -\Delta u = \lambda u + |u|^{2^* -2}u & \hbox{in}\ B_1\\ u=0 & \hbox{on}\ ... More
Geometry of genus 8 Nikulin surfaces and rationality of their moduliSep 10 2015Let S be a general complex Nikulin surface of genus 8, a geometric construction of S is given as follows. Consider a smooth 3-fold linear section T of the Grassmannian G(1,4) and the Hilbert scheme of rational normal sextic curves of T. In it consider ... More
Bilinear quantum systems on compact graphs: well-posedness and global exact controllabilityOct 16 2017Jul 12 2018We consider the bilinear Schr\"odinger equations on compact quantum graphs. We prove the well-posedness and the global exact controllability according to the structure of the graph. We apply the main results to examples involving star graphs and tadpole ... More
Rigidity ConjecturesDec 04 2018We prove several rigidity results for corona $\mathrm{C}^*$-algebras and \v{C}ech-Stone remainders under the assumption of Forcing Axioms. In particular, we prove that a strong version of Todor\v{c}evi\'c's OCA and Martin's Axiom at level $\aleph_1$ imply: ... More
X-ray Resonant Magnetic Scattering : Polarisation Dependence in the non-spherical caseJun 06 2006Jul 24 2006We develop a simple tensorial contraction method to obtain analytical formula for X-ray resonant magnetic scattering. We apply the method considering first electric dipole-dipole and electric quadrupole-quadrupole scattering in the isolated atom approximation ... More
Sommerfeld corrections to type-II and III leptogenesisJun 10 2008Oct 09 2008We study thermal leptogenesis from decays of the electroweak triplets that mediate neutrino masses in type-II and type-III see-saw. We find that Sommerfeld corrections reduce the baryon asymmetry by ~30%, and that successful leptogenesis needs triplets ... More
Oscillations of three neutrinos with all Delta m^2 approx 10^{-3} eV^2Apr 06 1999Apr 27 1999Oscillations of three neutrinos with all squared mass splittings around 10^{-3} eV^2 are not firmly excluded by solar neutrino experiments. We carefully verify that they are also perfectly compatible with atmospheric neutrino experiments: due to accidental ... More
Baryogenesis via leptogenesisAug 31 2006We discuss how leptogenesis can explain the observed baryon asymmetry and summarize attempts of testing leptogenesis. We first perform estimates and discuss the main physics, and later outline the techniques that allow to perform precise computations. ... More
A primer on Answer Set ProgrammingAug 23 2005A introduction to the syntax and Semantics of Answer Set Programming intended as an handout to [under]graduate students taking Artificial Intlligence or Logic Programming classes.
Epigenetic Tracking: Implementation DetailsJan 18 2010"Epigenetic Tracking" is the name of a model of cellular development that, coupled with an evolutionary technique, becomes an evo-devo (or "artificial embryology", or "computational development") method to generate 2d or 3d sets of artificial cells arbitrarily ... More