Results for "L. Rossi"

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Study of solid 4He in two dimensions. The issue of zero-point defects and study of confined crystalMar 21 2012Defects are believed to play a fundamental role in the supersolid state of 4He. We report on studies by exact Quantum Monte Carlo (QMC) simulations at zero temperature of the properties of solid 4He in presence of many vacancies, up to 30 in two dimensions ... More
Quantum dislocations: the fate of multiple vacancies in two dimensional solid 4HeJul 21 2009Mar 18 2010Defects are believed to play a fundamental role in the supersolid state of 4He. We have studied solid 4He in two dimensions (2D) as function of the number of vacancies n_v, up to 30, inserted in the initial configuration at rho = 0.0765 A^-2, close to ... More
New ${\cal W}_{q,p}(sl(2))$ algebras from the elliptic algebra ${\cal A}_{q,p}({\hat sl}(2)_c)$Jun 13 1997We construct operators t(z) in the elliptic algebra introduced by Foda et al. ${\cal A}_{q,p}({\hat sl}(2)_c)$. They close an exchange algebra when p^m=q^{c+2} for m integer. In addition they commute when p=q^{2k} for k integer non-zero, and they belong ... More
On the Quasi-Hopf structure of deformed double YangiansJan 06 2000We construct universal twists connecting the centrally extended double Yangian DY(sl(2))_c with deformed double Yangians DY_r(sl(2))_c, thereby establishing the quasi-Hopf structures of the latter.
Universal construction of W_{p,q} algebrasJul 09 1998We present a direct construction of abstract generators for q-deformed W_N algebras. This procedure hinges upon a twisted trace formula for the elliptic algebra A_{q,p}(sl(N)_c) generalizing the previously known formulae for quantum groups.
Poisson structures on the center of the elliptic algebra A_{p,q}(sl(2)_c)May 16 1997It is shown that the elliptic algebra A_{p,q}(sl(2)_c) has a non trivial center at the critical level $c=-2$, generalizing the result of Reshetikhin and Semenov-Tian-Shansky for trigonometric algebras. A family of Poisson structures indexed by a non-negative ... More
Ionic liquid gating of ultra-thinYBa$_2$Cu$_3$O$_{7-x}$ filmsNov 16 2016In this paper, we present a detailed investigation of the self-field transport properties of an ionic liquid gated ultra-thin YBa$_2$Cu$_3$O$_{7-x}$ film. From the high temperature dynamic of the resistivity ($> 220 \textrm{ K}$) different scenarios pertaining ... More
The U_A(1) Problem on the Lattice with Ginsparg-Wilson FermionsAug 07 2001Oct 11 2001We show how it is possible to give a precise and unambiguous implementation of the Witten--Veneziano formula for the eta' mass on the lattice, which looks like the formal continuum one, if the expression of the topological charge density operator, suggested ... More
Equivariant cohomology and localization for Lie algebroidsJun 20 2005Oct 14 2008Let M be a manifold carrying the action of a Lie group G, and A a Lie algebroid on M equipped with a compatible infinitesimal G-action. Out of these data we construct an equivariant Lie algebroid cohomology and prove for compact G a related localization ... More
Manufacturing and Testing of Accelerator Superconducting MagnetsJan 28 2015Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of ... More
Geometric TransitionsDec 28 2004The purpose of this paper is to give, on one hand, a mathematical exposition of the main topological and geometrical properties of geometric transitions, on the other hand, a quick outline of their principal applications, both in mathematics and in physics. ... More
The geometric lattice of embedded subsetsDec 17 2016This work proposes an alternative approach to the so-called lattice of embedded subsets, which is included in the product of the subset and partition lattices of a finite set, and whose elements are pairs consisting of a subset and a partition where the ... More
Weighted paths between partitionsSep 06 2015Dec 10 2016How to quantify the distance between any two partitions of a finite set is an important issue in statistical classification, whenever different clustering results need to be compared. Developing from the traditional Hamming distance between subsets or ... More
The Geometry of Spherical Random FieldsMar 24 2016In this PhD Thesis we investigate the geometry of random fields on compact Riemannian manifolds, in particular the two-dimensional sphere. In the first part, we characterize isotropic Gaussian fields on homogeneous spaces of a compact group and then we ... 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
Well-posedness of general 1D Initial Boundary Value Problems for scalar balance lawsSep 17 2018We focus on the initial boundary value problem for a general scalar balance law in one space dimension. Under rather general assumptions on the flux and source functions, we prove the well-posedness of this problem and the stability of its solutions with ... More
Embedding non-projective Mori Dream SpacesSep 07 2018Jan 29 2019This paper is devoted to extend some Hu-Keel results on Mori dream spaces (MDS) beyond the projective setup. Namely, $\Q$-factorial algebraic varieties with finitely generated class group and Cox ring, here called \emph{weak} Mori dream spaces (wMDS), ... More
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
Étale coverings in codimension 1 with applications to Mori Dream SpacesFeb 13 2019The present paper is devoted to developing relations between Galois \'etale coverings in codimension 1 and \'etale fundamental groups in codimension 1 of algebraic varieties, aimed to studying the topology of Mori dream spaces. In particular, the universal ... More
Symmetrization and anti-symmetrization in parabolic equationsApr 13 2016Apr 28 2016We derive some symmetrization and anti-symmetrization properties of parabolic equations. First, we deduce from a result by Jones a quantitative estimate of how far the level sets of solutions are from being spherical. Next, using this property, we derive ... More
Conceptual design of 20 T dipoles for high-energy LHCAug 08 2011Availability of 20 T operational field dipole magnets would open the way for a 16.5 TeV beam energy accelerator in the LHC tunnel. Here we discuss the main issues related to the magnet design of this extremely challenging dipole: main constraints, superconductor ... More
Microscopic studies of solid 4He with Path Integral Projector Monte CarloJul 27 2007We have investigated the ground state properties of solid $^4$He with the Shadow Path Integral Ground State method. This exact T=0 K projector method allows to describes quantum solids without introducing any a priori equilibrium position. We have found ... More
Revisiting Role Discovery in Networks: From Node to Edge RolesOct 04 2016Nov 07 2016Previous work in network analysis has focused on modeling the mixed-memberships of node roles in the graph, but not the roles of edges. We introduce the edge role discovery problem and present a generalizable framework for learning and extracting edge ... More
HE-LHC beam-parameters, optics and beam-dynamics issuesAug 08 2011The Higher-Energy LHC (HE-LHC) should collide two proton beams of 16.5-TeV energy, circulating in the LHC tunnel. We discuss the main parameter choices, as well as some optics and beam dynamics issues, in particular the time evolution of emittances, beam-beam ... More
Two-strain ecoepidemic systems: the obligated mutualism caseFeb 28 2014We present a model for obligated mutualistic associations, in which two transmissible diseases are allowed to infect just one population. As the general model proves too hard to be fully analytically investigated, some special cases are analysed. Among ... More
Definitions of solutions to the IBVP for multiD scalar balance lawsMay 25 2017We consider four definitions of solution to the initial-boundary value problem for a scalar balance laws in several space dimensions. These definitions are generalised to the same most general framework and then compared. The first aim of this paper is ... More
New Physics at CDFJun 06 2010We present the current status of searches for physics beyond the Standard Model at the Tevatron 1.96-TeV proton-antiproton collider using data collected with the CDF experiment. We cover searches for supersymmetry, extra dimensions and new gauge bosons. ... More
Second-order Dirac superconductors and magnetic field induced Majorana hinge modesJan 22 2019We identify three dimensional higher-order superconductors characterized by the coexistence of one-dimensional Majorana hinge states and gapped or gapless surface sates. We show how such superconductors can be obtained starting from the model of a spinful ... More
Minimal free resolution of a finitely generated module over a regular local ringApr 28 2008Nov 05 2009Numerical invariants of a minimal free resolution of a module $M$ over a regular local ring $(R,\n)$ can be studied by taking advantage of the rich literature on the graded case. The key is to fix suitable $\n$-stable filtrations ${\mathbb M} $ of $M ... More
On properties of the Generalized Wasserstein distanceApr 25 2013Nov 17 2014The Wasserstein distances $W_p$ ($p\geq 1$), defined in terms of solution to the Monge-Kantorovich problem, are known to be a useful tool to investigate transport equations. In particular, the Benamou-Brenier formula characterizes the square of the Wasserstein ... More
Invariant Carnot-Caratheodory metrics on $S^3$, $SO(3)$, $SL(2)$ and lens spacesSep 25 2007Jan 24 2008In this paper we study the invariant Carnot-Caratheodory metrics on $SU(2)\simeq S^3$, $SO(3)$ and $SL(2)$ induced by their Cartan decomposition and by the Killing form. Beside computing explicitly geodesics and conjugate loci, we compute the cut loci ... More
Projective Reeds-Shepp car on $S^2$ with quadratic costMay 30 2008Fix two points $x,\bar{x}\in S^2$ and two directions (without orientation) $\eta,\bar\eta$ of the velocities in these points. In this paper we are interested to the problem of minimizing the cost $$ J[\gamma]=\int_0^T g_{\gamma(t)}(\dot\gamma(t),\dot\gamma(t))+ ... More
A low-temperature scanning tunneling microscope capable of microscopy and spectroscopy in a Bitter magnet at up to 34 TJul 10 2017We present the design and performance of a cryogenic scanning tunneling microscope (STM) which operates inside a water-cooled Bitter magnet, which can attain a magnetic field of up to 38 T. Due to the high vibration environment generated by the magnet ... More
Master Wilson loop operators in large-N lattice QCD$_2$Dec 20 1994An explicit solution is found for the most general independent correlation functions in lattice QCD$_2$ with Wilson action. The large-$N$ limit of these correlations may be used to reconstruct the eigenvalue distributions of Wilson loop operators for ... More
Finite size scaling in CP(N-1) modelsJan 18 1993Finite size effects in Euclidean ${\rm CP}^{N-1}$ models with periodic boundary conditions are investigated by means of the $1/N$ expansion and by Monte Carlo simulations. Analytic and numerical results for magnetic susceptibility and correlation length ... More
Singular vanishing-viscosity limits of gradient flows: the finite-dimensional caseNov 24 2016In this note we study the singular vanishing-viscosity limit of a gradient flow set in a finite-dimensional Hilbert space and driven by a smooth, but possibly non convex, time-dependent energy functional. We resort to ideas and techniques from the variational ... More
On the correlation between nodal and boundary lengths for random spherical harmonicsFeb 15 2019We study the correlation between the nodal length of random spherical harmonics and the measure of the boundary for excursion sets at any non-zero level. We show that the correlation is asymptotically zero, while the partial correlation after controlling ... More
On measures that improve $L^q$ dimension under convolutionDec 13 2018Mar 19 2019The $L^q$ dimensions, for $1<q<\infty$, quantify the degree of smoothness of a measure. We study the following problem on the real line: when does the $L^q$ dimension improve under convolution? This can be seen as a variant of the well-known $L^p$-improving ... More
Hölder coverings of sets of small dimensionFeb 03 2017Feb 06 2018We show that a set of small box counting dimension can be covered by a H\"older graph from all but a small set of directions, and give sharp bounds for the dimension of the exceptional set, improving a result of B. Hunt and V. Kaloshin. We observe that, ... 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
Quantum Information in Semiconductors: Noiseless Encoding in a Quantum-Dot ArrayApr 06 1998Nov 20 1998A potential implementation of quantum-computation schemes in semiconductor-based structures is proposed. In particular, an array of quantum dots is shown to be an ideal quantum register for a noiseless information encoding. In addition to the suppression ... More
Stein-Malliavin Approximations for Nonlinear Functionals of Random Eigenfunctions on ${\mathbb{S}}^{d}$May 14 2014We investigate Stein-Malliavin approximations for nonlinear functionals of geometric interest of Gaussian random eigenfunctions on the unit $d$ -dimensional sphere ${\mathbb{S}}^{d},$ $d\geq 2.$ All our results are established in the high energy limit, ... More
A traffic flow model with non-smooth metric interaction: well-posedness and micro-macro limitOct 15 2015We prove existence and uniqueness of solutions to a transport equation modelling vehicular traffic in which the velocity field depends non-locally on the downstream traffic density via a discontinuous anisotropic kernel. The result is obtained recasting ... More
Theoretical Considerations on the Computation of Generalized Time-Periodic WavesMay 20 2011We present both, theory and an algorithm for solving time-harmonic wave problems in a general setting. The time-harmonic solutions will be achieved by computing time-periodic solutions of the original wave equations. Thus, an exact controllability technique ... More
A numerical ampleness criterion via Gale dualityApr 27 2015Nov 16 2016The main object of the present paper is a numerical criterion determining when a Weil divisor of a $\Q$--factorial complete toric variety admits a positive multiple Cartier divisor which is either numerically effective (nef) or ample. It is a consequence ... More
Weighted Projective Spaces from the toric point of view with computational applicationsDec 07 2011Feb 12 2013The purpose of the present paper is threefold. First: giving a treatise on weighted projective spaces by the toric point of view. Second: providing characterizations of fans and polytopes giving weighted projective spaces, with particular focus on a kind ... More
Stability for Borell-Brascamp-Lieb inequalitiesJul 19 2016We study stability issues for the so-called Borell-Brascamp-Lieb inequalities, proving that when near equality is realized, the involved functions must be $L^1$-close to be $p$-concave and to coincide up to homotheties of their graphs.
The high spin expansion of twist sector dimensions: the planar N=4 super Yang-Mills theoryApr 07 2010May 12 2010This review is devoted to collecting some results on the high spin expansion of (minimal) anomalous dimension. Thanks to the recent rationale on integrability, planar ${\cal N}=4$ super Yang-Mills theory (or its $\text{AdS}_5\times\text{S}^5$ string counterpart) ... More
IDNet: Smartphone-based Gait Recognition with Convolutional Neural NetworksJun 10 2016Oct 19 2016Here, we present IDNet, a user authentication framework from smartphone-acquired motion signals. Its goal is to recognize a target user from their way of walking, using the accelerometer and gyroscope (inertial) signals provided by a commercial smartphone ... More
On Lévy's Brownian motion indexed by the elements of compact groupsOct 02 2013We investigate positive definiteness of the Brownian kernel K(x,y)=1/2(d(x,x_0) + d(y,x_0) - d(x,y)) on a compact group G and in particular for G=SO(n).
Flavour non-conservation in goldstino interactionsJun 03 2000Aug 28 2000We point out that the interactions of goldstinos with matter supermultiplets are a potential source of flavour violation, if fermion and sfermion mass matrices are not aligned and supersymmetry is spontaneously broken at a low scale. We study the impact ... More
Comment on A. Patrascioiu and E. Seiler's paper ``Nonuniformity of the $1/N$ Expansion for Two-Dimensional $O(N)$ Models''Jul 14 1994We remind that the non-uniformity in the temperature of the $1/N$ expansion for dimensionful quantities pointed out in Patrascioiu and Seiler's paper is not only compatible with but is predicted by asymptotic freedom, and it is present in the continuum ... More
Fibration and classification of smooth projective toric varieties of low Picard numberJul 02 2015Dec 24 2015In this paper we show that a smooth toric variety $X$ of Picard number $r\leq 3$ always admits a nef primitive collection supported on a hyperplane admitting non-trivial intersection with the cone $\Nef(X)$ of numerically effective divisors. In particular ... More
A Batyrev type classification of $Q$--factorial projective toric varietiesApr 24 2015Sep 13 2017The present paper is devoted to generalizing, inside the class of projective toric varieties, the classification [Batyrev91], performed by Batyrev in 1991 for smooth complete toric varieties, to the singular $Q$--factorial case. Moreover, in the first ... More
Holonomy and parallel transport in the differential geometry of the space of loops and the groupoid of generalized gauge transformationsJan 15 2004The motivation for this paper stems \cite{CR} from the need to construct explicit isomorphisms of (possibly nontrivial) principal $G$-bundles on the space of loops or, more generally, of paths in some manifold $M$, over which I consider a fixed principal ... More
Subdecoherent Information Encoding in a Quantum-Dot ArrayAug 21 1998Nov 19 1998A potential implementation of quantum-information schemes in semiconductor nanostructures is studied. To this end, the formal theory of quantum encoding for avoiding errors is recalled and the existence of noiseless states for model systems is discussed. ... More
A Q-factorial complete toric variety is a quotient of a poly weighted spaceFeb 03 2015Sep 01 2017We prove that every Q-factorial complete toric variety is a finite quotient of a poly weighted space (PWS), as defined in our previous work arXiv:1501.05244. This generalizes the Batyrev-Cox and Conrads description of a Q-factorial complete toric variety ... More
Propagation phenomena for time heterogeneous KPP reaction-diffusion equationsApr 19 2011May 02 2011We investigate in this paper propagation phenomena for the heterogeneous reaction-diffusion equation $\partial_t u -\Delta u = f(t,u)$, $x\in R^N$, $t\in\R$, where f=f(t,u) is a KPP monostable nonlinearity which depends in a general way on t. A typical ... More
The logarithmic star product in the linear case and the Grothendieck--Teichmüller groupMay 22 2012Jun 09 2012The purpose of this short note is to establish an explicit equivalence between two star products $\star$ and $\star_{\log}$ on the symmetric algebra $\mathrm S(\mathfrak g)$ of a finite-dimensional Lie algebra $\mathfrak g$ over a field $\mathbb K\supset\mathbb ... More
Measure dynamics with Probability Vector Fields and sourcesSep 09 2018We introduce a new formulation for differential equation describing dynamics of measures on an Euclidean space, that we call Measure Differential Equations with sources. They mix two different phenomena: on one side, a transport-type term, in which a ... More
On the space of injective linear maps from $\bbR^d$ into $\bbR^m$Jan 31 2005In this short note, we investigate some features of the space $\Inject{d}{m}$ of linear injective maps from $\bbR^d$ into $\bbR^m$; in particular, we discuss in detail its relationship with the Stiefel manifold $V_{m,d}$, viewed, in this context, as the ... More
A Large-Scale Study on Source Code Reviewer RecommendationJun 20 2018Context: Software code reviews are an important part of the development process, leading to better software quality and reduced overall costs. However, finding appropriate code reviewers is a complex and time-consuming task. Goals: In this paper, we propose ... More
The Chevalley--Eilenberg complex and deformation quantization in presence of two branesMay 30 2011Jan 10 2012In this note, we prove that, for a finite-dimensional Lie algebra $\mathfrak g$ over a field $\mathbb K$ of characteristic 0 which contains $\mathbb C$, the Chevalley--Eilenberg complex $\mathrm U(\mathfrak g)\otimes \wedge(\mathfrak g)$, which is in ... More
Computational procedures for weighted projective spacesDec 07 2011This is a pdf print of the homonymous Maple file, freely available at http://www.maplesoft.com/applications/view.aspx?SID=127621, providing procedures which are able to produce the toric data associated with a (polarized) weighted projective space i.e. ... More
Reconstructing the initial mass function of disc-bulge Galactic globular clusters from N-body simulationsOct 08 2014We propose an evolutionary model to describe the dynamical evolution of star cluster systems in tidal fields, in which we calibrated the parametric equations defining the model by running direct N-body simulations of star clusters with a wide range of ... More
Bose Einstein Condensation in solid 4HeMar 17 2005We have computed the one--body density matrix rho_1 in solid 4He at T=0 K using the Shadow Wave Function (SWF) variational technique. The accuracy of the SWF has been tested with an exact projector method. We find that off-diagonal long range order is ... More
Topological susceptibility in full QCD with Ginsparg-Wilson fermionsFeb 23 2004We show that, if the formula for the topological charge density operator suggested by fermions obeying the Ginsparg-Wilson relation is employed, it is possible to give a precise and unambiguous definition of the topological susceptibility in full QCD, ... More
The structure of the inverse system of Gorenstein k-algebrasMay 16 2017Macaulay's Inverse System gives an effective method to construct Artinian Gorenstein k-algebras. To date a general structure for Gorenstein k-algebras of any dimension (and codimension) is not understood. In this paper we extend Macaulay's correspondence ... More
Hyperbolic predators vs parabolic preysFeb 10 2014We present a nonlinear predator-prey system consisting of a nonlocal conservation law for predators coupled with a parabolic equation for preys. The drift term in the predators' equation is a nonlocal function of the prey density, so that the movement ... More
Construction of nice nilpotent Lie groupsMar 25 2018Feb 15 2019We illustrate an algorithm to classify nice nilpotent Lie algebras of dimension $n$ up to a suitable notion of equivalence; applying the algorithm, we obtain complete listings for $n\leq9$. On every nilpotent Lie algebra of dimension $\leq 7$, we determine ... More
Isomorphism classes of short Gorenstein local rings via Macaulay's inverse systemNov 18 2009In this paper we study the isomorphism classes of Artinian Gorenstein local rings with socle degree three by means of Macaulay's inverse system. We prove that their classification is equivalent to the projective classification of the hypersurfaces of ... More
Einstein nilpotent Lie groupsJul 14 2017Apr 26 2018We study the Ricci tensor of left-invariant pseudoriemannian metrics on Lie groups. For an appropriate class of Lie groups that contains nilpotent Lie groups, we introduce a variety with a natural $\mathrm{GL}(n,\mathbb{R})$ action, whose orbits parametrize ... More
The Ricci tensor of almost parahermitian manifoldsMay 06 2016Oct 15 2017We study the pseudoriemannian geometry of almost parahermitian manifolds, obtaining a formula for the Ricci tensor of the Levi-Civita connection. The formula uses the intrinsic torsion of an underlying SL(n,R)-structure; we express it in terms of exterior ... More
Cohomology of D-complex manifoldsJan 12 2012In order to look for a well-behaved counterpart to Dolbeault cohomology in D-complex geometry, we study the de Rham cohomology of an almost D-complex manifold and its subgroups made up of the classes admitting invariant, respectively anti-invariant, representatives ... More
Stability of the 1D IBVP for a Non Autonomous Scalar Conservation LawJan 22 2016We prove the stability with respect to the flux of solutions to initial-boundary value problems for scalar non-autonomous conservation laws in one space dimension. Key estimates are obtained through a careful construction of the solutions.
Differential operators on toric varieties and Fourier transformMay 11 2007Jun 01 2007We show that Fourier transforms on the Weyl algebras have a geometric counterpart in the framework of toric varieties, namely they induce isomorphisms between twisted rings of differential operators on regular toric varieties, whose fans are related to ... More
On the Nature of Charge Transport in Quantum-Cascade LasersAug 21 2001The first global quantum simulation of semiconductor-based quantum-cascade lasers is presented. Our three-dimensional approach allows to study in a purely microscopic way the current-voltage characteristics of state-of-the-art unipolar nanostructures, ... More
Analytic Isomorphisms of compressed local algebrasJul 30 2012In this paper we consider Artin local K-algebras with maximal length in the class of Artin algebras with given embedding dimension and socle type. They have been widely studied by several authors, among others by Iarrobino, Fr\"oberg and Laksov. If the ... More
Ricci-flat and Einstein pseudoriemannian nilmanifoldsDec 04 2018This is partly an expository paper, where the authors' work on pseudoriemannian Einstein metrics on nilpotent Lie groups is reviewed. A new criterion is given for the existence of a diagonal Einstein metric on a nice nilpotent Lie group. Classifications ... More
Games for eigenvalues of the Hessian and concave/convex envelopesJan 10 2018We study the PDE $\lambda_j(D^2 u) = 0$, in $\Omega$, with $u=g$, on $\partial \Omega$. Here $\lambda_1(D^2 u) \leq ... \leq \lambda_N (D^2 u)$ are the ordered eigenvalues of the Hessian $D^2 u$. First, we show a geometric interpretation of the viscosity ... More
Renormalization group evaluation of exponents in family name distributionsFeb 13 2009Apr 03 2009According to many phenomenological and theoretical studies the distribution of family name frequencies in a population can be asymptotically described by a power law. We show that the Galton-Watson process corresponding to the dynamics of a growing population ... More
Hybrid CPU-GPU Framework for Network MotifsAug 18 2016Massively parallel architectures such as the GPU are becoming increasingly important due to the recent proliferation of data. In this paper, we propose a key class of hybrid parallel graphlet algorithms that leverages multiple CPUs and GPUs simultaneously ... More
A Theory of Sampling for Continuous-time Metric Temporal LogicNov 30 2009Apr 06 2010This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models ... More
Lepton flavour violation in the supersymmetric type-II seesaw mechanismSep 17 2008We summarize the predictions for the radiative decays l_j->l_i \gamma within the context of the supersymmetric type II seesaw mechanism considering universal boundary conditions for the soft SUSY breaking terms. The dependence on the low-energy neutrino ... More
Relating seesaw neutrino masses, lepton flavor violation and SUSY breakingSep 29 2006We discuss a GUT realization of the supersymmetric triplet seesaw mechanism(recently proposed by us in hep-ph/0604083 and further analyzed in hep-ph/0607298) where the exchange of the heavy triplet states generates both neutrino masses and soft SUSY breaking ... More
Electronic phase coherence versus dissipation in solid-state quantum devices: Two approximations are better than oneJan 27 2016In the microscopic modeling of new-generation electronic quantum nanodevices a variety of simulation strategies have been proposed and employed. Aim of this Letter is to point out virtues versus intrinsic limitations of non-Markovian density-matrix approaches; ... More
The Ricci tensor of almost parahermitian manifoldsMay 06 2016We study the pseudoriemannian geometry of almost parahermitian manifolds, obtaining a formula for the Ricci tensor of the Levi-Civita connection. The formula uses the intrinsic torsion of an underlying SL(n,R)-structure; we express it in terms of exterior ... More
Streams collision as possible precursor of double tidal disruption eventsMay 23 2018The rate of tidal disruption events (TDEs) can vary by orders of magnitude depending on the environment and the mechanism that launches the stars towards the black hole's vicinity. For the largest rates, two disruptions can take place shortly one after ... More
Indefinite Einstein metrics on nice Lie groupsMay 22 2018Feb 18 2019We introduce a systematic method to produce left-invariant, non-Ricci-flat Einstein metrics of indefinite signature on nice nilpotent Lie groups. On a nice nilpotent Lie group, we give a simple algebraic characterization of non-Ricci-flat left-invariant ... More
Stability of the 1D IBVP for a Non Autonomous Scalar Conservation LawJan 22 2016Oct 24 2016We prove the stability with respect to the flux of solutions to initial-boundary value problems for scalar non-autonomous conservation laws in one space dimension. Key estimates are obtained through a careful construction of the solutions.
The Gamma--Ray Burst catalog obtained with the Gamma Ray Burst Monitor aboard BeppoSAXSep 30 2008We report on the catalog of Gamma--Ray Bursts (GRBs) detected with the Gamma Ray Burst Monitor aboard the BeppoSAX satellite. It includes 1082 GRBs with 40--700 keV fluences in the range from $1.3\times 10^{-7}$ to $4.5\times 10^{-4}$ erg cm$^{-2}$, and ... More
Toward a global description of the nucleus-nucleus interactionFeb 05 2002Extensive systematization of theoretical and experimental nuclear densities and of optical potential strengths exctracted from heavy-ion elastic scattering data analyses at low and intermediate energies are presented.The energy-dependence of the nuclear ... More
Deformed Double Yangian StructuresMay 18 1999Scaling limits when q tends to 1 of the elliptic vertex algebras A_qp(sl(N)) are defined for any N, extending the previously known case of N=2. They realise deformed, centrally extended double Yangian structures DY_r(sl(N)). As in the quantum affine algebras ... More
Central extensions of classical and quantum q-Viraroso algebrasJun 11 1998We investigate the central extensions of the q-deformed (classical and quantum) Virasoro algebras constructed from the elliptic quantum algebra A_{q,p}[sl(N)_c]. After establishing the expressions of the cocycle conditions, we solve them, both in the ... More
Lower and upper bounds for the first eigenvalue of nonlocal diffusion problems in the whole spaceNov 17 2011We find lower and upper bounds for the first eigenvalue of a nonlocal diffusion operator of the form $ T(u) = - \int_{\rr^d} K(x,y) (u(y)-u(x)) \, dy$. Here we consider a kernel $K(x,y)=\psi (y-a(x))+\psi(x-a(y))$ where $\psi$ is a bounded, nonnegative ... More
The high energy X-ray tail of Eta Car revealed by BeppoSAXFeb 13 2004We report on the June 2000 long (100 ks) BeppoSAX exposure that has unveiled above 10 keV a new very high energy component of the X-ray spectrum of Eta Car extending to at least 50 keV. We find that the 2-150 keV spectrum is best reproduced by a thermal ... More
Inhomogeneity and nonlinear screening in gapped bilayer grapheneApr 25 2012Nov 05 2012We demonstrate that for gapped bilayer graphene, the nonlinear nature of the screening of an external disorder potential and the resulting inhomogeneity of the electron liquid are crucial for describing the electronic compressibility. In particular, traditional ... More
Properties of X-Ray Rich Gamma Ray Bursts and X-Ray Flashes detected with BeppoSAX and Hete-2Nov 09 2005Aug 08 2006We study the spectrum of the prompt emission and the X-ray and optical afterglow fluxes of 54 X-Ray Rich Gamma Ray Burst (XRRs) and X-Ray Flashes (XRFs), observed by BeppoSax and HETE-2. A comparison is then performed with classical Gamma Ray Bursts (GRBs). ... More
Zero-point vacancies in quantum solidsJun 13 2008A Jastrow wave function (JWF) and a shadow wave function (SWF) describe a quantum solid with Bose--Einstein condensate; i.e. a supersolid. It is known that both JWF and SWF describe a quantum solid with also a finite equilibrium concentration of vacancies ... More
Quantized vortices in two dimensional solid 4HeNov 08 2011Diagonal and off-diagonal properties of 2D solid 4He systems doped with a quantized vortex have been investigated via the Shadow Path Integral Ground State method using the fixed-phase approach. The chosen approximate phase induces the standard Onsager-Feynman ... More