Results for "Lorenzo Di Pietro"

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Scaling dimensions in QED$_3$ from the $ε$-expansionAug 12 2017We study the fixed point that controls the IR dynamics of QED in $d = 4 - 2\epsilon$. We derive the scaling dimensions of four-fermion and bilinear operators beyond leading order in $\epsilon$-expansion. For the four-fermion operators, this requires the ... More
Cardy Formula for 4d SUSY Theories and LocalizationNov 01 2016Jan 05 2017We study 4d $\mathcal{N}=1$ supersymmetric theories on a compact Euclidean manifold of the form $S^1 \times\mathcal{M}_3$. Partition functions of gauge theories on this background can be computed using localization, and explicit formulas have been derived ... More
Confining vacua in SQCD, the Konishi anomaly and the Dijkgraaf-Vafa superpotentialAug 30 2011Sep 05 2011In this paper we revisit the analysis of vacua in N=2 SQCD with generic bare quark masses, softly broken by a mass term for the chiral superfield \Phi in the adjoint representation of the gauge group. These vacua are labelled by an integer r (r vacua) ... More
Operator mixing in $\boldsymbolε$-expansion: scheme and evanescent (in)dependenceAug 12 2017We consider theories with fermionic degrees of freedom that have a fixed point of Wilson-Fisher type in non-integer dimension $d = 4-2\epsilon$. Due to the presence of evanescent operators, i.e., operators that vanish in integer dimensions, these theories ... More
Programmable interactions with biomimetic DNA linkers at fluid membranes and interfacesMar 31 2019At the heart of the structured architecture and complex dynamics of biological systems are specific and timely interactions operated by biomolecules. In many instances, biomolecular agents are spatially confined to flexible lipid membranes where, among ... More
A Hybrid High-Order method for the incompressible Navier--Stokes equations based on Temam's deviceJul 19 2018Oct 10 2018In this work we propose a novel Hybrid High-Order method for the incompressible Navier--Stokes equations based on a formulation of the convective term including Temam's device for stability. The proposed method has several advantageous features: it supports ... More
On Supersymmetry, Boundary Actions and Brane ChargesFeb 20 2015Feb 22 2016Supersymmetry transformations change the Lagrangian $\mathscr{L}$ into a total derivative $\delta \mathscr{L} = \partial_\mu \mathcal{V}^{\mu}$. On manifolds with boundaries the total derivative term is an obstruction to preserving supersymmetry. Such ... More
't Hooft anomalies and the holomorphy of supersymmetric partition functionsMay 14 2019We study the dependence of supersymmetric partition functions on continuous parameters for the flavor symmetry group, $G_F$, for 2d $\mathcal{N} = (0,2)$ and 4d $\mathcal{N}=1$ supersymmetric quantum field theories. In any diffeomorphism-invariant scheme ... More
Quantum Electrodynamics in d=3 from the epsilon-expansionAug 25 2015Sep 25 2015We study Quantum Electrodynamics in d=3 (QED_3) coupled to N_f flavors of fermions. The theory flows to an IR fixed point for N_f larger than some critical number N_f^c. For N_f<= N_f^c, chiral-symmetry breaking is believed to take place. In analogy with ... More
3d Abelian Gauge Theories at the BoundaryFeb 25 2019A four-dimensional Abelian gauge field can be coupled to a 3d CFT with a $U(1)$ symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFT) parametrized by the gauge coupling $\tau$ in the ... More
A Hybrid High-Order discretisation of the Brinkman problem robust in the Darcy and Stokes limitsMar 29 2018Jul 23 2018In this work, we develop and analyse a novel Hybrid High-Order discretisation of the Brinkman problem. The method hinges on hybrid discrete velocity unknowns at faces and elements and on discontinuous pressures. Based on the discrete unknowns, we reconstruct ... More
The Role of Optical Projection in the Analysis of Membrane FluctuationsNov 16 2015We propose a methodology to measure the mechanical properties of membranes from their fluctuations and apply this to optical microscopy measurements of giant unilamellar vesicles of lipids. We analyze the effect of the projection of thermal shape undulations ... More
Volume and porosity thermal regulation in lipid mesophases by coupling mobile ligands to soft membranesJul 21 2014Jan 09 2015Short DNA linkers are increasingly being exploited for driving specific self-assembly of Brownian objects. DNA-functionalised colloids can assemble into ordered or amorphous materials with tailored morphology. Recently, the same approach has been applied ... More
Holographic Correlators for General Gauge MediationMay 21 2012Jun 27 2012We use holographic techniques to compute two-point functions of operators belonging to a conserved current supermultiplet in theories which break supersymmetry at strong coupling. These are the relevant quantities one has to compute in models of gauge ... More
The Casimir Energy in Curved Space and its Supersymmetric CounterpartMar 18 2015Jul 20 2015We study $d$-dimensional Conformal Field Theories (CFTs) on the cylinder, $S^{d-1}\times \mathbb{R}$, and its deformations. In $d=2$ the Casimir energy (i.e. the vacuum energy) is universal and is related to the central charge $c$. In $d=4$ the vacuum ... More
Cohomological invariants of the stack of hyperelliptic curves of odd genusApr 06 2018Dec 05 2018We compute the cohomological invariants of $\mathcal{H}_g$, the moduli stack of smooth hyperelliptic curves, for every odd $g$.
Picard group of moduli of curves of low genus in positive characteristicDec 05 2018We compute the Picard group of the moduli stack of smooth curves of genus $g$ for $3\leq g\leq 5$, using methods of equivariant intersection theory. We base our proof on the computation of some relations in the integral Chow ring of certain moduli stacks ... More
Diffusion Adaptation Strategies for Distributed Estimation over Gaussian Markov Random FieldsJul 14 2014The aim of this paper is to propose diffusion strategies for distributed estimation over adaptive networks, assuming the presence of spatially correlated measurements distributed according to a Gaussian Markov random field (GMRF) model. The proposed methods ... More
Pluricanonical systems for 3-folds and 4-folds of general typeJan 19 2010Sep 28 2011We explicitly find lower bounds on the volume of threefolds and fourfolds of general type in order to have nonvanishing of pluricanonical systems and birationality of pluricanonical maps. In the case of threefolds of large volume, we also give necessary ... More
The Chow ring of the stack of hyperelliptic curves of odd genusFeb 13 2018Apr 06 2018We find a new presentation of the stack of hyperelliptic curves of odd genus as a quotient stack and we use it to compute its integral Chow ring by means of equivariant intersection theory.
SOS - Securing Open SkiesSep 24 2018Nov 27 2018Automatic Dependent Surveillance - Broadcast (ADS-B) is the next generation communication technology selected for allowing commercial and military aircraft to deliver flight information to both ground base stations and other airplanes. Today, it is already ... More
A Spark is Enough in a Straw World: a Study of Websites Password Management in the WildApr 19 2018Apr 24 2018The widespread usage of password authentication in online websites leads to an ever-increasing concern, especially when considering the possibility for an attacker to recover the user password by leveraging the loopholes in the password recovery mechanisms. ... More
Silence is Golden: exploiting jamming and radio silence to communicateJul 22 2013Jamming techniques require just moderate resources to be deployed, while their effectiveness in disrupting communications is unprecedented. In this paper we introduce several contributions to jamming mitigation. In particular, we introduce a novel adversary ... More
Virtualization Technologies and Cloud Security: advantages, issues, and perspectivesJul 29 2018Aug 02 2018Virtualization technologies allow multiple tenants to share physical resources with a degree of security and isolation that cannot be guaranteed by mere containerization. Further, virtualization allows protected transparent introspection of Virtual Machine ... More
$W^{s,p}$-approximation properties of elliptic projectors on polynomial spaces, with application to the error analysis of a Hybrid High-Order discretisation of Leray-Lions problemsJun 09 2016Jan 30 2017In this work we prove optimal $W^{s,p}$-approximation estimates (with $p\in[1,+\infty]$) for elliptic projectors on local polynomial spaces. The proof hinges on the classical Dupont--Scott approximation theory together with two novel abstract lemmas: ... More
Euler pseudoprimes for half of the basesSep 16 2011We prove that an odd number is an Euler pseudoprime for exactly one half of the admissible bases if and only if it is a special Carmichael number.
Echo State Networks with Self-Normalizing Activations on the Hyper-SphereMar 27 2019Among the various architectures of Recurrent Neural Networks, Echo State Networks (ESNs) emerged due to their simplified and inexpensive training procedure. These networks are known to be sensitive to the setting of hyper-parameters, which critically ... More
A characterization of the Edge of Criticality in Binary Echo State NetworksOct 03 2018Echo State Networks (ESNs) are simplified recurrent neural network models composed of a reservoir and a linear, trainable readout layer. The reservoir is tunable by some hyper-parameters that control the network behaviour. ESNs are known to be effective ... More
Klein-Gordon-Maxwell System in a bounded domainFeb 29 2008This paper is concerned with the Klein-Gordon-Maxwell system in a bounded spatial domain. We discuss the existence of standing waves $\psi=u(x)e^{-i\omega t}$ in equilibrium with a purely electrostatic field $\mathbf{E}=-\nabla\phi(x)$. We assume an homogeneous ... More
Hard X / soft gamma ray polarimetry using a Laue lensSep 06 2011Hard X / soft gamma-ray polarimetric analysis can be performed efficiently by the study of Compton scattering anisotropy in a detector composed of fine pixels. But in the energy range above 100 keV where sources flux are extremely weak and instrumental ... More
Dirichlet and Neumann problems for Klein-Gordon-Maxwell systemsDec 16 2008This paper deals with the Klein-Gordon-Maxwell system in a bounded spatial domain. We study the existence of solutions having a specific form, namely standing waves in equilibrium with a purely electrostatic field. We prescribe Dirichlet boundary conditions ... More
Apolarity, Hessian and Macaulay polynomialsJul 28 2010Oct 08 2012A result by Macaulay states that an Artinian graded Gorenstein ring R of socle dimension one and socle degree b can be realized as the apolar ring of a homogeneous polynomial f of degree b. If R is the Jacobian ring of a smooth hypersurface g=0, then ... More
Restricted volumes of effective divisorsJul 05 2012We study the restricted volume of effective divisors, its properties and the relationship with the related notion of reduced volume, defined via multiplier ideals, and with the asymptotic intersection number. We build upon the fundamental work of Lazarsfeld ... More
Small noise asymptotic of the Gallavotti-Cohen functional for diffusion processesApr 14 2010We consider, for a diffusion process in R^n, the Gallavotti-Cohen functional, defined as the empirical power dissipated in a time interval by the non-conservative part of the drift. We prove a large deviation principle in the limit in which the noise ... More
Asymptotic base loci on singular varietiesMay 06 2011Oct 18 2012We prove that the non-nef locus and the restricted base locus of a pseudoeffective divisor coincide on KLT pairs. We also extend to KLT pairs F. Russo's characterization of nef and abundant divisors by means of asymptotic multiplier ideals.
A Framework for Parallel and Distributed Training of Neural NetworksOct 24 2016The aim of this paper is to develop a general framework for training neural networks (NNs) in a distributed environment, where training data is partitioned over a set of agents that communicate with each other through a sparse, possibly time-varying, ... More
A Framework for Parallel and Distributed Training of Neural NetworksOct 24 2016Apr 20 2017The aim of this paper is to develop a general framework for training neural networks (NNs) in a distributed environment, where training data is partitioned over a set of agents that communicate with each other through a sparse, possibly time-varying, ... More
HyBIS: Windows Guest Protection through Advanced Memory IntrospectionJan 22 2016Effectively protecting the Windows OS is a challenging task, since most implementation details are not publicly known. Windows has always been the main target of malwares that have exploited numerous bugs and vulnerabilities. Recent trusted boot and additional ... More
CloRoFor: Cloud Robust ForensicsJun 04 2015The malicious alteration of machine time is a big challenge in computer forensics. Detecting such changes and reconstructing the actual timeline of events is of paramount importance. However, this can be difficult since the attacker has many opportunities ... More
A Hybrid High-Order method for nonlinear elasticityJul 07 2017In this work we propose and analyze a novel Hybrid High-Order discretization of a class of (linear and) nonlinear elasticity models in the small deformation regime which are of common use in solid mechanics. The proposed method is valid in two and three ... More
Spectral sequence associated with a symplectic manifoldNov 06 2006A method of computation of its terms is presented together with some stabilization results. As an application a characterization of symplectic harmonic manifolds is given and a relationship with the C-spectral sequence is indicated.
From diffusion experiments to mean-field theory simulations and backApr 11 2019Using previous experimental data of diffusion in metallic alloys, we obtain real values for an interpolation parameter introduced in a mean-field theory for diffusion with interaction. Values of order 1 were found as expected, finding relevance for this ... More
A Hybrid High-Order method for the steady incompressible Navier--Stokes problemJul 27 2016In this work we introduce and analyze a novel Hybrid High-Order method for the steady incompressible Navier-Stokes equations. The proposed method is inf-sup stable on general polyhedral meshes, supports arbitrary approximation orders, and is (relatively) ... More
A third Strang lemma and an Aubin-Nitsche trick for schemes in fully discrete formulationApr 25 2018Nov 13 2018In this work, we present an abstract error analysis framework for the approximation of linear partial differential equation (PDE) problems in weak formulation. We consider approximation methods in fully discrete formulation, where the discrete and continuous ... More
Strictly Temporally Periodic Points in Cellular AutomataAug 14 2012We study the set of strictly periodic points in surjective cellular automata, i.e., the set of those configurations which are temporally periodic for a given automaton but they not spatially periodic. This set turns out to be dense for almost equicontinuous ... More
A Majoritarian Representative Voting SystemNov 30 2016We present an alternative voting system that aims at bridging the gap between proportional representative systems and majoritarian, single winner election systems. The system lets people vote for multiple parties, but then assigns each ballot to a single ... More
An introduction to Hybrid High-Order methodsMar 15 2017Apr 20 2017This chapter provides an introduction to Hybrid High-Order (HHO) methods. These are new generation numerical methods for PDEs with several advantageous features: the support of arbitrary approximation orders on general polyhedral meshes, the reproduction ... More
Equilibrated tractions for the Hybrid High-Order methodNov 01 2014Dec 01 2014We show how to recover equilibrated face tractions for the hybrid high-order method for linear elasticity recently introduced in [D. A. Di Pietro and A. Ern, A hybrid high-order locking-free method for linear elasticity on general meshes, Comput. Meth. ... More
CUDA Leaks: Information Leakage in GPU ArchitecturesMay 31 2013Jul 15 2013Graphics Processing Units (GPUs) are deployed on most present server, desktop, and even mobile platforms. Nowadays, a growing number of applications leverage the high parallelism offered by this architecture to speed-up general purpose computation. This ... More
Convergence and synchronization in heterogeneous networks of smooth and piecewise smooth systemsApr 07 2014This paper presents a framework for the study of convergence when the nodes' dynamics may be both piecewise smooth and/or nonidentical across the network. Specifically, we derive sufficient conditions for global convergence of all node trajectories towards ... More
A Hybrid High-Order method for Leray-Lions elliptic equations on general meshesAug 08 2015Dec 07 2016In this work, we develop and analyze a Hybrid High-Order (HHO) method for steady non-linear Leray-Lions problems. The proposed method has several assets, including the support for arbitrary approximation orders and general polytopal meshes. This is achieved ... More
Achieving Convergence and Synchronization in Networks of Piecewise-Smooth Systems via Distributed Discontinuous CouplingMay 14 2019Piecewise-smooth systems are common in applications, ranging from dry friction oscillators in mechanics, to power converters in electrical engineering, to neuron cells in biology. While the properties of stability and the control of such dynamical systems ... More
System-Generated Requests for Rewriting ProposalsNov 30 2016We present an online deliberation system using mutual evaluation in order to collaboratively develop solutions. Participants submit their proposals and evaluate each other's proposals; some of them may then be invited by the system to rewrite 'problematic' ... More
Beyond topological persistence: Starting from networksJan 19 2019Nowadays, data generation, representation and analysis occupy central roles in human society. Therefore, it is necessary to develop frameworks of analysis able of adapting to diverse data structures with minimal effort, much as guaranteeing robustness ... More
Vanishing Viscosity Limits of Scalar Equations with Degenerate DiffusivityJan 05 2018We consider a scalar, possibly degenerate parabolic equation with a source term, in several space dimensions. For initial data with bounded variation we prove the existence of solutions to the initial-value problem. Then we show that these solutions converge, ... More
Sharp profiles in models of collective movementsFeb 17 2017We consider a parabolic partial differential equation that can be understood as a simple model for crowds flows. Our main assumption is that the diffusivity and the source/sink term vanish at the same point; the nonhomogeneous term is different from zero ... More
Ramsey properties of nonlinear Diophantine equationsJun 07 2016We prove general sufficient and necessary conditions for the partition regularity of Diophantine equations, which extend the classic Rado's Theorem by covering large classes of nonlinear equations. Sufficient conditions are obtained by exploiting algebraic ... More
Cardy Formula for 4d SUSY Theories and LocalizationNov 01 2016We study 4d $\mathcal{N}=1$ supersymmetric theories on a compact Euclidean manifold of the form $S^1 \times\mathcal{M}_3$. Partition functions of gauge theories on this background can be computed using localization, and explicit formulas have been derived ... More
Graph topology inference based on sparsifying transform learningJun 05 2018Graph-based representations play a key role in machine learning. The fundamental step in these representations is the association of a graph structure to a dataset. In this paper, we propose a method that aims at finding a block sparse representation ... More
Cardy Formulae for SUSY Theories in d=4 and d=6Jul 22 2014Oct 14 2014We consider supersymmetric theories on a space with compact space-like slices. One can count BPS representations weighted by (-1)^F, or, equivalently, study supersymmetric partition functions by compactifying the time direction. A special case of this ... More
Statistics of nondemolition weak measurementNov 12 2012A measurement consists in coupling a system to a probe and reading the output of the probe to gather information about the system. The weaker the coupling, the smaller the back-action on the system, but also the less information conveyed. If the system ... More
Sampling and Recovery of Graph SignalsDec 26 2017The aim of this chapter is to give an overview of the recent advances related to sampling and recovery of signals defined over graphs. First, we illustrate the conditions for perfect recovery of bandlimited graph signals from samples collected over a ... More
Accidental Peccei-Quinn symmetry protected to arbitrary orderApr 04 2017A $SU(N)_L\times SU(N)_R$ gauge theory for a scalar multiplet $Y$ transforming in the bi-fundamental representation $(N,\bar N)$ preserves, for $N>4$, an accidental $U(1)$ symmetry firstly broken at operator dimension $N$. Two configurations are possible ... More
A monoidal representation for linearized gravityDec 16 2016Jan 30 2017We propose an alternative representation for linear quantum gravity. It is based on the use of a structure that bears some resemblance to the Abelian loop representation used in electromagnetism but with the difference that space of extended object on ... More
Evidence of an exponential speed-up in the solution of hard optimization problemsOct 23 2017Optimization problems pervade essentially every scientific discipline and industry. Many such problems require finding a solution that maximizes the number of constraints satisfied. Often, these problems are particularly difficult to solve because they ... More
Unified Fock space representation of fractional quantum Hall statesMay 19 2017Many bosonic (fermionic) fractional quantum Hall states, such as Laughlin, Moore-Read and Read-Rezayi wavefunctions, belong to a special class of orthogonal polynomials: the Jack polynomials (times a Vandermonde determinant). This fundamental observation ... More
Resilient Design of 5G Mobile-Edge Computing Over Intermittent mmWave LinksJan 07 2019Mar 28 2019Two enablers of the 5th Generation (5G) of mobile communication systems are the high data rates achievable with millimeter-wave radio signals and the cloudification of the network's mobile edge, made possible also by Multi-access Edge Computing (MEC). ... More
A Hybrid High-Order method for Kirchhoff-Love plate bending problemsJun 21 2017Jan 24 2018We present a novel Hybrid High-Order (HHO) discretization of fourth-order elliptic problems arising from the mechanical modeling of the bending behavior of Kirchhoff-Love plates, including the biharmonic equation as a particular case. The proposed HHO ... More
A discontinuous-skeletal method for advection-diffusion-reaction on general meshesNov 01 2014May 27 2018We design and analyze an approximation method for advection-diffusion-reaction equations where the (generalized) degrees of freedom are polynomials of order $k\ge0$ at mesh faces. The method hinges on local discrete reconstruction operators for the diffusive ... More
Jack on a Devil's staircaseNov 21 2017Nov 22 2017We review a simple mechanism for the formation of plateaux in the fractional quantum Hall effect. It arises from a map of the microscopic Hamiltonian in the thin torus limit to a lattice gas model, solved by Hubbard. The map suggests a Devil's staircase ... More
Mapping the File Systems Genome: rationales, technique, results and applicationsJun 12 2013This paper provides evidence of a feature of Hard-Disk Drives (HDDs), that we call File System Genome. Such a feature is originated by the areas where (on the HDD) the file blocks are placed by the operating system during the installation procedure. It ... More
Picking a Needle in a Haystack: Detecting Drones via Network Traffic AnalysisJan 11 2019We propose PiNcH, a methodology to detect the presence of a drone and its current status leveraging just the communication traffic exchanged between the drone and its Remote Controller (RC). PiNcH is built applying standard classification algorithms to ... More
A nonconforming high-order method for the Biot problem on general meshesJun 11 2015Feb 24 2016In this work, we introduce a novel algorithm for the Biot problem based on a Hybrid High-Order discretization of the mechanics and a Symmetric Weighted Interior Penalty discretization of the flow. The method has several assets, including, in particular, ... More
Hölder regularity for non divergence form elliptic equations with discontinuous coefficientsOct 18 2012In this note we study the global regularity in the Morrey spaces for the second derivatives for the strong solutions of non variational elliptic equations.
A Hybrid High-Order method for the Cahn-Hilliard problem in mixed formSep 24 2015Apr 08 2016In this work, we develop a fully implicit Hybrid High-Order algorithm for the Cahn-Hilliard problem in mixed form. The space discretization hinges on local reconstruction operators from hybrid polynomial unknowns at elements and faces. The proposed method ... More
Discontinuous Skeletal Gradient Discretisation Methods on polytopal meshesJun 29 2017Dec 06 2017In this work we develop arbitrary-order Discontinuous Skeletal Gradient Discretisations (DSGD) on general polytopal meshes. Discontinuous Skeletal refers to the fact that the globally coupled unknowns are broken polynomial on the mesh skeleton. The key ... More
A low-order nonconforming method for linear elasticity on general meshesFeb 06 2019In this work we construct a low-order nonconforming approximation method for linear elasticity problems supporting general meshes and valid in two and three space dimensions. The method is obtained by hacking the Hybrid High-Order method, that requires ... More
On varieties with higher osculating defectApr 19 2012In this paper, using the method of moving frames, we generalise some of Terracini's results on varieties with tangent defect. In particular, we characterise varieties with higher order osculating defect in terms of Jacobians of higher fundamental forms ... More
BAD: Blockchain Anomaly DetectionJul 10 2018Jul 12 2018Anomaly detection tools play a role of paramount importance in protecting networks and systems from unforeseen attacks, usually by automatically recognizing and filtering out anomalous activities. Over the years, different approaches have been designed, ... More
Foundations, Properties, and Security Applications of Puzzles: A SurveyApr 23 2019Cryptographic algorithms have been used not only to create robust ciphertexts, but also to generate cryptograms that, contrary to the classic goal of cryptography, are meant to be broken. These cryptograms, generally called puzzles, required the use of ... More
A prototype-based approach to object reclassificationAug 13 2018We investigate, in the context of functional prototype-based lan- guages, a calculus of objects which might extend themselves upon receiving a message, a capability referred to by Cardelli as a self-inflicted operation. We present a sound type system ... More
(Non-)Decoupled Supersymmetric Field TheoriesFeb 14 2014We study some consequences of coupling supersymmetric theories to (super)gravity. To linear order, the couplings are determined by the energy-momentum supermultiplet. At higher orders, the couplings are determined by contact terms in correlation functions ... More
A Study of Quantum Field Theories in AdS at Finite CouplingOct 09 2018Jan 10 2019We study the $O(N)$ and Gross-Neveu models at large $N$ on AdS$_{d+1}$ background. Thanks to the isometries of AdS, the observables in these theories are constrained by the SO$(d,2)$ conformal group even in the presence of mass deformations, as was discussed ... More
Holographic R-symmetric flows and the τ_U conjectureApr 04 2013Jul 17 2013We discuss the holographic counterpart of a recent conjecture regarding R-symmetric RG-flows in four-dimensional supersymmetric field theories. In such theories, a quantity \tau_U can be defined at the fixed points which was conjectured in arXiv:1109.3279 ... More
Dynamical completions of generalized O'Raifeartaigh modelsNov 09 2011Dec 18 2012We present gauge theory completions of Wess-Zumino models admitting supersymmetry breaking vacua with spontaneously broken R-symmetry. Our models are simple deformations of generalized ITIY models, a supersymmetric theory with gauge group Sp(N), N+1 flavors ... More
X-ray spectral evolution of V404 Cygni in the initial phase of the 2015 outburstOct 12 2015The black hole binary GS 2023+338 exhibited an unprecedently bright outburst on June 2015. Since June 17th, the high energy instruments on board INTEGRAL detected an extremely variable emission during both bright and low luminosity phases, with dramatic ... More
First INTEGRAL observations of V404 Cygni during the 2015 outburst : spectral behavior in the 20 - 650 keV energy rangeOct 13 2015In June 2015, the source V404 Cygni (= GS2023+38) underwent an extraordinary outburst. We present the results obtained during the first revolution dedicated to this target by the INTEGRAL mission, and focus on the spectral behavior in the hard X-ray domain, ... More
Quantum effects in muon spin spectroscopy within the stochastic self-consistent harmonic approximationApr 26 2019In muon spin rotation experiments the positive implanted muon vibrates with large zero point amplitude by virtue of its light mass. Quantum mechanical calculations of the host material usually treat the muon as a point impurity, ignoring this large vibrational ... More
Steric interactions between mobile ligands facilitate complete wrapping in passive endocytosisAug 11 2017Aug 21 2018Receptor-mediated endocytosis is an ubiquitous process through which cells internalize biological or synthetic nanoscale objects, including viruses, unicellular parasites, and nanomedical vectors for drug or gene delivery. In passive endocytosis the cell ... More
Slow relaxation of disordered memristive networksAug 30 2016Oct 21 2016Networks with memristive elements (resistors with memory) are being explored for a variety of applications ranging from unconventional computing to models of the brain. Using graph-theoretic tools, we show that the memory dynamics promotes scale-free ... More
Distributed Adaptive Learning of Graph SignalsSep 20 2016The aim of this paper is to propose distributed strategies for adaptive learning of signals defined over graphs. Assuming the graph signal to be band-limited, the method enables distributed reconstruction, with guaranteed performance in terms of mean-square ... More
Observing and Tracking Bandlimited Graph ProcessesDec 01 2017Oct 19 2018One of the most crucial challenges in graph signal processing is the sampling of bandlimited graph signals, i.e., signals that are sparse in a well-defined graph Fourier domain. So far, the prior art is mostly focused on (sub)sampling single snapshots ... More
Slow relaxation of disordered memristive networksAug 30 2016Networks with memristive elements (resistors with memory) are being explored for a variety of applications ranging from unconventional computing to models of the brain. Using graph-theoretic tools, we show that the memory dynamics promotes scale-free ... More
Black Hole entropy for two higher derivative theories of gravitySep 24 2010Nov 12 2010The dark energy issue is focusing the attention of an incresing number of physicists all over the world. Among the possible alternatives in order to explain what as been named the "Mystery of the Millennium" are the so-called Modified Theories of Gravity. ... More
Galaxy spin as a formation probe: the stellar-to-halo specific angular momentum relationNov 13 2017Apr 14 2018We derive the stellar-to-halo specific angular momentum relation (SHSAMR) of galaxies at $z=0$ by combining i) the standard $\Lambda$CDM tidal torque theory ii) the observed relation between stellar mass and specific angular momentum (Fall relation) and ... More
The angular momentum-mass relation: a fundamental law from dwarf irregulars to massive spiralsApr 12 2018In a $\Lambda$CDM Universe, the specific stellar angular momentum ($j_\ast$) and stellar mass ($M_\ast$) of a galaxy are correlated as a consequence of the scaling existing for dark matter haloes ($j_{\rm h}\propto M_{\rm h}^{2/3}$). The shape of this ... More
Electrodynamic properties of an artificial heterostructured superconducting cuprateAug 01 2017We perform infrared conductivity measurements on a series of CaCuO$_2$/SrTiO$_3$ heterostructures made by the insulating cuprate CaCuO$_2$ (CCO) and the insulating perovkite SrTiO$_3$ (STO). We estimate the carrier density of various heterostructures, ... More
Digital holographic microscopy for the evaluation of human sperm structureJul 12 2013The morphology of the sperm head has often been correlated with the outcome of in vitro fertilization (IVF), and has been shown to be the sole parameter in semen of value in predicting the success of intracytoplasmic sperm injection (ICSI) and intracytoplasmic ... More
The paradigm-shift of social spambots: Evidence, theories, and tools for the arms raceJan 11 2017Recent studies in social media spam and automation provide anecdotal argumentation of the rise of a new generation of spambots, so-called social spambots. Here, for the first time, we extensively study this novel phenomenon on Twitter and we provide quantitative ... More
The Smallville Effect: Social Ties Make Mobile Networks More Secure Against the Node Capture AttackDec 11 2009Mobile Ad Hoc networks, due to the unattended nature of the network itself and the dispersed location of nodes, are subject to several unique security issues. One of the most vexed security threat is node capture. A few solutions have already been proposed ... More