Results for "Pietro Danzi"

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Anti-Jamming Strategy for Distributed Microgrid Control based on Power Talk CommunicationDec 21 2016Dec 22 2016In standard implementations of distributed secondary control for DC MicroGrids (MGs), the exchange of local measurements among neighboring control agents is enabled via off-the-shelf wireless solutions, such as IEEE 802.11. However, Denial of Service ... More
Analysis of the Communication Traffic for Blockchain Synchronization of IoT DevicesNov 01 2017Feb 12 2018Blockchain is a technology uniquely suited to support massive number of transactions and smart contracts within the Internet of Things (IoT) ecosystem, thanks to the decentralized accounting mechanism. In a blockchain network, the states of the accounts ... More
Delay and Communication Tradeoffs for Blockchain Systems with Lightweight IoT ClientsJul 19 2018Oct 17 2018The emerging blockchain protocols provide a decentralized architecture that is suitable of supporting Internet of Things (IoT) interactions. However, keeping a local copy of the blockchain ledger is infeasible for low-power and memory-constrained devices. ... More
Distributed Proportional-Fairness Control in MicroGrids via Blockchain Smart ContractsMay 03 2017May 16 2017Residential microgrids (MGs) may host a large number of Distributed Energy Resources (DERs). The strategy that maximizes the revenue for each individual DER is the one in which the DER operates at capacity, injecting all available power into the grid. ... More
Software-Defined Microgrid Control for Resilience Against Cyber AttacksFeb 08 2018Microgrids (MGs) rely on networked control supported by off-the-shelf wireless communications. This makes them vulnerable to cyber-attacks, such as denial-of-service (DoS). In this paper, we mitigate those attacks by applying the concepts of (i) separation ... More
Secure and Robust Authentication for DC MicroGrids based on Power Talk CommunicationDec 21 2016Dec 22 2016We propose a novel framework for secure and reliable authentication of Distributed Energy Resources to the centralized secondary/tertiary control system of a DC MicroGrid (MG), networked using the IEEE 802.11 wireless interface. The key idea is to perform ... More
Secure and Resilient Low-Rate Connectivity for Smart Energy Applications through Power Talk in DC MicrogridsMar 29 2017The future smart grid is envisioned as a network of interconnected microgrids (MGs) - small-scale local power networks comprising generators, storage capacities and loads. MGs bring unprecedented modularity, efficiency, sustainability, and resilience ... More
On the Impact of Wireless Jamming on the Distributed Secondary Microgrid ControlSep 22 2016The secondary control in direct current microgrids (MGs) is used to restore the voltage deviations caused by the primary droop control, where the latter is implemented locally in each distributed generator and reacts to load variations. Numerous recent ... More
Communication Aspects of the Integration of Wireless IoT Devices with Distributed Ledger TechnologyMar 05 2019The pervasive need to safely share and store information between devices calls for the replacement of centralized trust architectures with the decentralized ones. Distributed Ledger Technologies (DLTs) are seen as the most promising enabler of decentralized ... More
Constraints on R-Parity violating stop couplings from flavor physicsAug 25 2000Nov 22 2000We perform a critical reassessment of the constraints on the R-parity and baryon number violating (s)top couplings coming from flavor physics. In particular, we study K0-K0bar mixing, including QCD corrections and a class of diagrams that were neglected ... More
Spectrally Perron Polynomials and the Cauchy-Ostrovsky TheoremAug 26 2016Oct 23 2016In this note, proofs of theorems attributed to Cauchy and Ostrovsky via combinatorial matrix theory and nonnegative matrix theory are given. We show that the sufficient conditions in each theorem are also necessary. In addition, we introduce the notion ... More
Supersymmetry and First Order Equations for Extremal States: Monopoles, Hyperinstantons, Black-Holes and p-BranesJan 13 1997Jan 16 1997In this lecture I review recent results on the first order equations describing BPS extremal states, in particular N=2 extremal black-holes. The role of special geometry is emphasized also in the rigid theory and a comparison is drawn with the supersymmetric ... More
CKM matrix: the `over-consistent' picture of the unitarity triangleNov 21 2000Dec 21 2000In presenting an up-to-date account of the experimental knowledge of the CKM matrix, special emphasis is placed on the exceptional degree of consistency shown by the current Standard Model determination of the unitarity triangle; some implications in ... More
Wall-Crossing Invariants from Spectral NetworksNov 01 2016A new construction of BPS monodromies for 4d ${\mathcal N}=2$ theories of class S is introduced. A novel feature of this construction is its manifest invariance under Kontsevich-Soibelman wall crossing, in the sense that no information on the 4d BPS spectrum ... More
Parameter free calculation of hadronic masses from instantonsNov 25 2001We propose a non-perturbative calculation scheme which is based on the semi-classical approximation of QCD and can be used to evaluate quantities of interest in hadronic physics. As a first application, we evaluate the mass of the pion and of the nucleon. ... More
Classification of deformation quantization algebroids on complex symplectic manifoldsMar 19 2005Dec 21 2005Deformation quantization algebroids over a complex symplectic manifold X are locally given by rings of WKB operators, that is, microdifferential operators with an extra central parameter \tau. In this paper, we will show that such algebroids are classified ... More
Comparing the automorphism group of the measure algebra with some groups related to the infinite permutation group of the natural numbersDec 27 2003We prove, by a straight construction, that the automorphism group of the measure algebra and the subgroup of the measure preserving ones cannot be isomorphic to the trivial automorphisms of P(N)/fin.
Representations of Atiyah algebroids and logarithmic connectionsMay 18 2015In this paper, we investigate representations of $\operatorname{At}(N)$, the Atiyah algebroids of a holomorphic line bundles $N$ over a complex manifold $Y$. In particular, we relate $\operatorname{At}(N)$-modules with logarithmic connections through ... More
A Tenth Hilbert Problem-like Result: The Decidability of MLS with Unordered Cartesian ProductFeb 27 2019Using the technique of formative processes, I solve the decidability problem of MLS with unordered cartesian product in the positive. Moreover I give a pure combinatorial description of the satisfiable MLS with unordered cartesian product-formulas for ... More
Free Differential Algebras, Rheonomy, and Pure SpinorsJan 20 2008We report on progresses on the derivation of pure spinor constraints, BRST algebra and BRST invariant sigma models a la pure spinors from the algebraic structure of the FDA underlying supergravity.
Constrained Supermanifolds for AdS M-Theory BackgroundsApr 25 2007A long standing problem is the supergauge completion of AdS_4 x (G/H)_7 or AdS_5 x (G/H)_5 backgrounds which preserve less then maximal supersymmetry. In parallel with the supersolvable realization of the AdS_4 x S^7 background based on Kappa-symmetry, ... More
Spectrally Perron Polynomials and the Cauchy-Ostrovsky TheoremAug 26 2016Oct 06 2016In this note, proofs of theorems attributed to Cauchy and Ostrovsky via combinatorial matrix theory and nonnegative matrix theory are given. We show that the sufficient conditions in each theorem are also necessary. In addition, we introduce the notion ... More
Rare $B$-Decays and Heavy to Light Semileptonic Transitions in the Isgur and Wise LimitNov 10 1993From the experimental branching ratios for $B^- --> \rho^0 l^-\bar\nu_l$ and $D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e$ one finds, in the Heavy Quark Limit of $HQET$, $ |V_{bu}|=(8.1\pm 1.7) x 10^{-3}$, larger but consistent with the actual quoted ... More
Gaugings and other supergravity tools of p-brane physicsFeb 19 2001Apr 01 2001In this series of lectures I present a review of the geometric structures of supergravity in diverse dimensions mostly relevant to p-brane physics and to pinpoint the correspondence between the macroscopic and microscopic description of branes. In particular ... More
The role of diffeomorphisms in the integration over a finite dimensional space of geometriesSep 24 1997Starting from the De Witt supermetric and limiting ourselves to a family of geometries characterized by a finite number of geometric invariants we extract the unique integration measure. Such a measure turns out to be a geometric invariant, i.e. independent ... More
The INTEGRAL - HESS/MAGIC connection: a new class of cosmic high energy accelerators from keV to TeVMay 09 2006The recent completion and operation of the High Energy Stereoscopic System, an array of ground based imaging Cherenkov telescopes, has provided a survey with unprecedented sensitivity of the inner part of the Galaxy and revealed a new population of very ... More
Long distance contributions to the eta_b => Jpsi Jpsi decayMar 21 2007Apr 08 2008It was argued long ago that eta_b could be observed through the eta_b => Jpsi(=> mu+ mu-) Jpsi(=> mu+ mu-) decay chain. Recent calculations indicate that the width of eta_b into two Jpsi is almost 3 orders of magnitude smaller than the one into the D ... More
Critical behavior of frustrated spin systems with nonplanar orderingsMay 13 2003Sep 26 2003The critical behavior of frustrated spin systems with nonplanar orderings is analyzed by a six-loop study in fixed dimension of an effective O$(N) \times $O$(M)$ Landau-Ginzburg-Wilson Hamiltonian. For this purpose the large-order behavior of the field ... More
Two-loop corrections to the Higgs boson masses in the MSSMMay 15 2002We present a computation of the O(at*as + at^2) two--loop corrections to the MSSM Higgs masses. An appropriate use of the effective potential approach allows us to obtain simple analytical formulae, valid for arbitrary values of mA and of the mass parameters ... More
Characterizing downwards closed, strongly first order, relativizable dependenciesSep 01 2018Feb 22 2019In Team Semantics, a dependency notion is strongly first order if every sentence of the logic obtained by adding the corresponding atoms to First Order Logic is equivalent to some first order sentence. In this work it is shown that all nontrivial dependency ... More
Combinatorial interpretations of particular evaluations of complete and elementary symmetric functionsNov 11 2011The Jacobi-Stirling numbers and the Legendre-Stirling numbers of the first and second kind were first introduced in [6], [7]. In this paper we note that Jacobi-Stirling numbers and Legendre-Stirling numbers are specializations of elementary and complete ... More
Human Computation and ConvergenceMar 19 2015May 06 2015Humans are the most effective integrators and producers of information, directly and through the use of information-processing inventions. As these inventions become increasingly sophisticated, the substantive role of humans in processing information ... More
Uniqueness of quantization of complex contact manifoldsDec 21 2005Using the language of algebroid stacks, we will show that Kashiwara's quantization of a complex contact manifold is unique.
Periodic solutions of forced Kirchhoff equationsJan 14 2007Jun 14 2007We consider Kirchhoff equations for vibrating bodies in any dimension in presence of a time-periodic external forcing with period 2pi/omega and amplitude epsilon, both for Dirichlet and for space-periodic boundary conditions. We prove existence, regularity ... More
An explicit bound for the log-canonical degree of curves on open surfacesJan 08 2019Let $X$, $D$ be a smooth projective surface and a simple normal crossing divisor on $X$, respectively. Suppose $\kappa (X, K_X + D)\ge 0$, let $C$ be an irreducible curve on $X$ whose support is not contained in $D$ and $\alpha$ a rational number in $ ... More
Pure Spinors, Free Differential Algebras, and the SupermembraneJun 19 2006The lagrangian formalism for the supermembrane in any 11d supergravity background is constructed in the pure spinor framework. Our gauge-fixed action is manifestly BRST, supersymmetric, and 3d Lorentz invariant. The relation between the Free Differential ... More
Dynamic Logics of Imperfect Information: from Teams and Games to TransitionsNov 22 2011Dec 15 2011We introduce a new semantical formalism for logics of imperfect information, based on Game Logic (and, in particular, on van Benthem, Ghosh and Lu's Concurrent Dynamic Game Logic). This new kind of semantics combines aspects from game theoretic semantics ... More
Riemann-Hilbert treatment of Liouville theory on the torusOct 24 2010Dec 05 2010We apply a perturbative technique to study classical Liouville theory on the torus. After mapping the problem on the cut-plane we give the perturbative treatment for a weak source. When the torus reduces to the square the problem is exactly soluble by ... More
Recent Results in Charmonium Spectroscopy at B-factoriesSep 14 2010Charmonium spectroscopy gained renewed interest after the discovery in 2003 of the unpredicted X(3872) charmonium-like state, above the $D\overline{D}$ threshold. To date many charmonium-like states above the $D\overline{D}$ threshold have been claimed. ... More
On the semiclassical treatment of Hawking radiationNov 23 2009Sep 19 2010In the context of the semiclassical treatment of Hawking radiation we prove the universality of the reduced canonical momentum for the system of a massive shell self gravitating in a spherical gravitational field within the Painlev\'e family of gauges. ... More
Measurements of Time-Dependent CP Asymmetries in b\to s Penguin Dominated Hadronic B Decays at BaBarSep 26 2009We report measurements of Time-Dependent CP asymmetries in several $b\to s$ penguin dominated hadronic B decays, where New Physics contributions may appear. We find no significant discrepancies with respect to the Standard Model expectations.
Rational fixed points for linear group actionsOct 23 2006Aug 16 2007Let $k$ be a finitely generated field, let $X$ be an algebraic variety and $G$ a linear algebraic group, both defined over $k$. Suppose $G$ acts on $X$ and every element of a Zariski-dense semigroup $\Gamma \subset G(k)$ has a rational fixed point in ... More
Semiclassical and quantum Liouville theoryDec 22 2005We develop a functional integral approach to quantum Liouville field theory completely independent of the hamiltonian approach. To this end on the sphere topology we solve the Riemann-Hilbert problem for three singularities of finite strength and a fourth ... More
BPS D3-branes on smooth ALE manifoldsOct 30 2001In this talk I review the recent construction of a new family of classical BPS solutions of type IIB supergravity describing 3-branes transverse to a 6-dimensional space with topology $\mathbb{R}^{2}\times$ALE. They are characterized by a non-trivial ... More
Solvable Lie Algebras, BPS Black Holes and Supergravity GaugingsFeb 07 1998In this talk I review both accomplished results and work in progress on the use of solvable Lie algebras as an intrinsic algebraic characterization of the scalar field sector of M--theory low energy effective lagrangians. In particular I review the application ... More
Non-Leptonic Two-Body Weak Decays of Charmed Mesons and CP-Violating AsymmetriesAug 06 1996The non-leptonic two body decays of D mesons are studied in the framework of an improved factorization approximation. The final state interaction effects are taken into account assuming them dominated by nearby resonances. The agreement with experimental ... More
Hamiltonian structure of 2+1 dimensional gravityFeb 14 2001A summary is given of some results and perspectives of the hamiltonian ADM approach to 2+1 dimensional gravity. After recalling the classical results for closed universes in absence of matter we go over the the case in which matter is present in the form ... More
On the monodromy problem for the four-punctured sphereJan 10 2014Apr 06 2014We consider the monodromy problem for the four-punctured sphere in which the character of one composite monodromy is fixed, by looking at the expansion of the accessory parameter in the modulus $x$ directly, without taking the limit of the quantum conformal ... More
Upwards Closed Dependencies in Team SemanticsMay 18 2013Jul 17 2013We prove that adding upwards closed first-order dependency atoms to first-order logic with team semantics does not increase its expressive power (with respect to sentences), and that the same remains true if we also add constancy atoms. As a consequence, ... More
SM single-top production at hadron collidersFeb 15 2013We give an overview of the status of theoretical predictions for single-top production in the Standard Model. We focus in particular on recent developments, including calculations of off-shell effects at next-to-leading order beyond the narrow-width approximation, ... More
$Λ$-modules and holomorphic Lie algebroid connectionsAug 16 2011Mar 21 2012Let $X$ be a complex smooth projective variety, and $\mathcal{G}$ a locally free sheaf on $X$. We show that there is a 1-to-1 correspondence between pairs $(\Lambda,\Xi)$, where $\Lambda$ is a sheaf of almost polynomial filtered algebras over $X$ satisfying ... More
Transition Semantics - The Dynamics of Dependence LogicMar 05 2012May 21 2013We examine the relationship between Dependence Logic and game logics. A variant of Dynamic Game Logic, called Transition Logic, is developed, and we show that its relationship with Dependence Logic is comparable to the one between First-Order Logic and ... More
Eisenstein's criterion, Fermat's last theorem, and a conjecture on powerful numbersApr 05 2017Feb 13 2018Given integers $\ell > m >0$, we define monic polynomials $X_n$, $Y_n$, and $Z_n$ with the property that $\mu$ is a zero of $X_n$ if and only if the triple $(\mu,\mu+m,\mu+\ell)$ satisfies $x^n + y^n = z^n$. It is shown that the irreducibility of these ... More
Periodic solutions of fully nonlinear autonomous equations of Benjamin-Ono typeFeb 15 2012Feb 20 2012We prove the existence of time-periodic, small amplitude solutions of autonomous quasilinear or fully nonlinear completely resonant pseudo-PDEs of Benjamin-Ono type in Sobolev class. The result holds for frequencies in a Cantor set that has asymptotically ... More
Characterizing Strongly First Order Dependencies: The Non-Jumping Relativizable CaseFeb 20 2019Team Semantics generalizes Tarski's Semantics for First Order Logic by allowing formulas to be satisfied or not satisfied by sets of assignments rather than by single assignments. Because of this, in Team Semantics it is possible to extend the language ... More
Applications of pathwise Burkholder-Davis-Gundy inequalitiesJul 05 2015We present several applications of the pathwise Burkholder-Davis-Gundy (BDG) inequalities. Most importantly we prove them for cadlag semimartingales and a general function $\Phi$, and use this to derive BDG inequalities (non-pathwise ones) for the Bessel ... More
On quantizations of complex contact manifoldsNov 20 2012Dec 31 2014A (holomorphic) quantization of a complex contact manifold is a filtered algebroid stack which is locally equivalent to the ring E of microdifferential operators and which has trivial graded. The existence of a canonical quantization has been proved by ... More
The arithmetical rank of a special class of monomial idealsMay 14 2010Jun 08 2010We give an affirmative answer to a question due to J. He and A. Van Tuyl, proving that the arithmetical rank of a special monomial ideal equals to the projective dimension of corresponding quotient module.
Riemann-Hilbert treatment of Liouville theory on the torus: The general caseApr 16 2011May 06 2011We extend the previous treatment of Liouville theory on the torus, to the general case in which the distribution of charges is not necessarily symmetric. This requires the concept of Fuchsian differential equation on Riemann surfaces. We show through ... More
Consistent gravitational anomalies for chiral scalarsOct 09 2010Starting from the Henneaux-Teitelboim action for a chiral scalar, which generalizes to curved space the Floreanini-Jackiw action, we give two simple derivations of the exact consistent gravitational anomaly. The first derivation is through the Schwinger-DeWitt ... More
Reduced Hamiltonian for intersecting shells and Hawking radiationDec 19 2009We consider the dynamics of one or more self gravitating shells of matter in a centrally symmetric gravitational field in the Painleve' family of gauges. We give the reduced hamiltonian for two intersecting shells, both massless and massive. Such a formulation ... More
Branching fractions and charge asymmetries in charmless hadronic B decays at BABARSep 14 2009We present measurements of branching fraction, polarization and charge asymmetry in charmless hadronic B decays with eta, eta', omega, and b_1 in the final state. All the results use the final BABAR dataset.
Final state interaction effects on the eta(b) => J/psi J/psi decayOct 15 2008We study the effects of final state interactions on the eta(b) => J/psi J/psi decay. In particular, we discuss the effects of the annihilation of eta(b) into two charmed meson and their rescattering into J/psi J/psi. We find that the inclusion of this ... More
Characterization of Protein Folding by Dominant Reaction PathwaysJun 23 2008We assess the reliability of the recently developed approach denominated Dominant Reaction Pathways (DRP) by studying the folding of a 16-residue beta-hairpin, within a coarse-grained Go-type model. We show that the DRP predictions are in quantitative ... More
Non invariant zeta-function regularization in quantum Liouville theoryDec 26 2006We consider two possible zeta-function regularization schemes of quantum Liouville theory. One refers to the Laplace-Beltrami operator covariant under conformal transformations, the other to the naive non invariant operator. The first produces an invariant ... More
A generalized small model property for languages which force the infinityNov 10 2004Dec 30 2004This paper deals with formulas of set theory which force the infinity. For such formulas, we provide a technique to infer satisfiability from a finite assignment.
On the $h \to V \ell^+ \ell^-$ decaysOct 05 2016A set of exclusive decays of the Higgs boson into a vector meson and a dilepton pair ($h\to V \ell^+ \ell^-$, with $V=\Upsilon, J/\psi,\phi$, and $\ell=\mu, \tau$) are studied in the framework of the Standard Model. We have evaluated the decay rates, ... More
Group theoretical derivation of Liouville action for Regge surfacesJul 10 1997We show that the structure of the Liouville action on a two dimensional Regge surface of the topology of the sphere and of the torus is determined by the invariance under the transformations induced by the conformal Killing vector fields and under modular ... More
U Duality, Solvable Lie Algebras and Extremal Black-HolesFeb 24 1997In this lecture I review recent results on the use of Solvable Lie Algebras as an efficient description of the scalar field sector of supergravities in relation with their non perturbative structure encoded in the U-duality group. I also review recent ... More
Partitions of a Finite Partially Ordered SetJul 05 2013In this paper, we investigate the notion of partition of a finite partially ordered set (poset, for short). We will define three different notions of partition of a poset, namely, monotone, regular, and open partition. For each of these notions we will ... More
A note on the Lovasz-Schrijver Semidefinite Programming Relaxation for Binary Integer ProgramsAug 10 2012Aug 18 2012Binary Integer Programming (BIP) problems are of interest due in part to the difficulty they pose and because of their various applications, including those in graph theory, combinatorial optimization and network optimization. In this note, we explicitly ... More
Late-time expansion in the semiclassical theory of the Hawking radiationJul 17 2011Sep 07 2011We give a detailed treatment of the back-reaction effects on the Hawking spectrum in the late-time expansion within the semiclassical approach to the Hawking radiation. We find that the boundary value problem defining the action of the modes which are ... More
Optimal Investment with Stocks and DerivativesOct 19 2012Oct 08 2013This paper studies the problem of maximizing expected utility from terminal wealth combining a static position in derivative securities, which we assume can be traded only at time zero, with a traditional dynamic trading strategy in stocks. We work in ... More
A general proof system for logics of imperfect informationJan 27 2012We develop a semantics for logics of imperfect information with respect to general models. Then we build a proof system and prove its soundness and completeness with respect to this semantics.
Indirect constraints on R-parity violating stop couplingsMar 31 2000Aug 04 2000It was recently claimed that single stop production at the Tevatron, occurring via R-parity (and baryon number) violating couplings, could lead to observable signals. In this talk I present some results of a work in progress, showing that rare B decays ... More
QCD Sum Rule Analysis of B \to (K,K^*) (\ell^+\ell^-,ν\barν) DecaysNov 15 1997We use three-point QCD sum rules to calculate the form factors governing the rare exclusive decays B \to (K,K^*) \ell^+ \ell^-, B \to (K,K^*) \nu \bar\nu. We predict the branching ratios, the invariant mass distributions of the lepton pair for B \to (K,K^*) ... More
The Complete Form of N=2 Supergravity and its Place in the General Framework of D=4 N--Extended SupergravitiesNov 22 1996Relying on the geometrical set up of Special K\"ahler Geometry and Quaternionic Geometry, which I discussed at length in my Lectures at the 1995 edition of this Spring School, I present here the recently obtained fully general form of N=2 supergravity ... More
Lectures on Special Kahler Geometry and Electric--Magnetic Duality RotationsDec 06 1995In these lectures I review the general structure of electric--magnetic duality rotations in every even space--time dimension. In four dimensions, which is my main concern, I discuss the general issue of symplectic covariance and how it relates to the ... More
Gravity in 2+1 dimensionsDec 06 1994A review is given of some classical and quantum aspects of 2+1 dimensional gravity.
Molecular Dynamics at Low Time ResolutionJun 25 2010The internal dynamics of macro-molecular systems is characterized by widely separated time scales, ranging from fraction of ps to ns. In ordinary molecular dynamics simulations, the elementary time step dt used to integrate the equation of motion needs ... More
Nonlinear Boltzmann equation for the homogeneous isotropic case: Minimal deterministic Matlab programApr 20 2010The homogeneous isotropic Boltzmann equation (HIBE) is a fundamental dynamic model for many applications in thermodynamics, econophysics and sociodynamics. Despite recent hardware improvements, the solution of the Boltzmann equation remains extremely ... More
CP Violation Results from B Decays at BaBarFeb 07 2011In the present paper we review recent experimental results from the BaBar experiment concerning the measurement of the CKM angles. A particular highlight is given to the novel independent determination of the angle alpha from B0 -> a_1(1260)+/- pi -/+ ... More
On the eta(b) => J/psi J/psi decayDec 21 2007It has been argued long ago that eta(b) could be observed through the eta(b) => J/psi(=> mu+ mu-) J/psi(=> mu+ mu-) decay chain. Recent calculations indicate that the width of eta(b) into two J/psi is almost three order of magnitude smaller than the one ... More
M-theory FDA, Twisted Tori and Chevalley CohomologyOct 09 2005Oct 18 2005The FDA algebras emerging from twisted tori compactifications of M-theory with fluxes are discussed within the general classification scheme provided by Sullivan's theorems and by Chevalley cohomology. It is shown that the generalized Maurer Cartan equations ... More
Instanton-Induced Correlations in HadronsNov 05 2004Dec 23 2004QCD instantons generate non-perturbative spin- and flavor- dependent forces between quarks. We review the results of a series of studies on instanton-induced correlations in hadrons. We first present some evidence for instanton-mediated interactions in ... More
Strong CP breaking and quark-antiquark repulsion in QCD, at finite thetaApr 16 2004May 05 2005This work is devoted to the study of the CP-breaking dynamics in QCD, at finite theta-angle. By working in the semi-classical limit, in which the topology of the vacuum is clustered around instantons and anti-instantons, we show that quantum fluctuations ... More
Uniform Poincare inequalities for unbounded conservative spin systems: The non-interacting caseFeb 04 2002Mar 17 2003We prove a uniform Poincare' inequality for non-interacting unbounded spin systems with a conservation law, when the single-site potential is a bounded perturbation of a convex function. The result is then applied to Ginzburg-Landau processes to show ... More
On the spectral gap of the Kac walk and other binary collision processesJul 22 2008We give a new and elementary computation of the spectral gap of the Kac walk on the N-sphere. The result is obtained as a by-product of a more general observation which allows to reduce the analysis of the spectral gap of an N-component system to that ... More
Quasi-periodic solutions of the equation v_{tt}-v_{xx}+v^3=f(v)Jun 05 2005Jul 06 2005We consider 1D completely resonant nonlinear wave equations of the type v_{tt}-v_{xx}=-v^3+O(v^4) with spatial periodic boundary conditions. We prove the existence of a new type of quasi-periodic small amplitude solutions with two frequencies, for more ... More
Safe Dependency Atoms and Possibility Operators in Team SemanticsAug 02 2018Sep 11 2018I consider the question of which dependencies are safe for a Team Semantics-based logic FO(D), in the sense that they do not increase its expressive power over sentences when added to it. I show that some dependencies, like totality, non-constancy and ... More
Lectures on gravitationMar 15 2017Lecture notes on selected topics in the theory of gravitation.
Wall-Crossing Invariants from Spectral NetworksNov 01 2016Jun 01 2017A new construction of BPS monodromies for 4d ${\mathcal N}=2$ theories of class S is introduced. A novel feature of this construction is its manifest invariance under Kontsevich-Soibelman wall crossing, in the sense that no information on the 4d BPS spectrum ... More
Equations and Rational Points of the Modular Curves $X^+_0(p)$Jul 15 2016Let $p$ be an odd prime number and let $X_0^+(p)$ be the quotient of the classical modular curve $X_0(p)$ by the action of the Atkin-Lehner operator $w_p$. In this paper we show how to compute explicit equations for the canonical model of $X_0^+(p)$. ... More
A Mathematica package to cope with partially ordered setsJul 04 2013Mathematica offers, by way of the package Combinatorics, many useful functions to work on graphs and ordered structures, but none of these functions was specific enough to meet the needs of our research group. Moreover, the existing functions are not ... More
The Doxastic Interpretation of Team SemanticsMay 21 2013We advance a doxastic interpretation for many of the logical connectives considered in Dependence Logic and in its extensions, and we argue that Team Semantics is a natural framework for reasoning about beliefs and belief updates.
Project G.N.O.S.I.S.: Geographical Network Of Synoptic Information SystemNov 03 2012Everybody knows how much synoptic maps are useful today. An excellent example above all is Google Earth: its simplicity and friendly interface allows every user to have the Earth maps ready in just one simple layout; nevertheless a crucial dimension is ... More
Tensor Networks: a quantum-information perspective on numerical renormalization groupsMay 18 2012Exact many-body quantum problems are known to be computationally hard due to the exponential scaling of the numerical resources required. Since the advent of the Density Matrix Renormalization Group, it became clear that a successful strategy to work ... More
Inclusion and Exclusion Dependencies in Team Semantics: On Some Logics of Imperfect InformationJun 07 2011Jun 11 2011We introduce some new logics of imperfect information by adding atomic formulas corresponding to inclusion and exclusion dependencies to the language of first order logic. The properties of these logics and their relationships with other logics of imperfect ... More
Matrix functions that preserve the strong Perron-Frobenius propertyJul 03 2014Jun 03 2015In this note, we characterize matrix functions that preserve the strong Perron-Frobenius property using the real Jordan canonical form of a real matrix.
On a dyadic approximation of predictable processes of finite variationJun 26 2013Mar 27 2014We show that any cadlag predictable process of finite variation is an a.s. limit of elementary predictable processes; it follows that predictable stopping times can be approximated `from below' by predictable stopping times which take finitely many values. ... More