Results for "Mario di Bernardo"

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Switching control for incremental stabilization of nonlinear systems via contraction theoryOct 28 2015Apr 05 2016In this paper we present a switching control strategy to incrementally stabilize a class of nonlinear dynamical systems. Exploiting recent results on contraction analysis of switched Filippov systems derived using regularization, sufficient conditions ... More
Contraction and incremental stability of switched Carathéodory systems using multiple normsFeb 21 2015Mar 01 2016In this paper, incremental exponential asymptotic stability of a class of switched Carath\'{e}odory nonlinear systems is studied based on the novel concept of measure of switched matrices via multiple norms and the transaction coefficients between these ... More
Distributed PID Control for Consensus of Homogeneous and Heterogeneous NetworksSep 08 2014Oct 21 2014We investigate the use of distributed PID actions to achieve consensus in networks of homogeneous and heterogeneous linear systems. Convergence of the strategy is proved for both cases using appropriate state transformations and Lyapunov functions. The ... More
Exploiting nodes symmetries to control synchronization and consensus patterns in multiagent systemsMar 01 2016Jun 21 2017We present new conditions to obtain synchronization and consensus patterns in complex network systems. The key idea is to exploit symmetries of the nodes' vector fields to induce a desired synchronization/consensus pattern, where nodes are clustered in ... More
Observer design for piecewise smooth and switched systems via contraction theoryNov 08 2016Apr 07 2017The aim of this paper is to present the application of an approach to study contraction theory recently developed for piecewise smooth and switched systems. The approach that can be used to analyze incremental stability properties of so-called Filippov ... More
Heterogeneity induces emergent functional networks for synchronizationJun 04 2015Jul 24 2015We study the evolution of heterogeneous networks of oscillators subject to a state-dependent interconnection rule. We find that heterogeneity in the node dynamics is key in organizing the architecture of the functional emerging networks. We demonstrate ... More
In-silico Feedback Control of a MIMO Synthetic Toggle Switch via Pulse-Width ModulationNov 15 2018The synthetic toggle switch, first proposed by Gardner & Collins [1] is a MIMO control system that can be controlled by varying the concentrations of two inducer molecules, aTc and IPTG, to achieve a desired level of expression of the two genes it comprises. ... 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
Using learning to control artificial avatars in human motor coordination tasksOct 09 2018Designing artificial cyber-agents able to interact with human safely, smartly and in a natural way is a current open problem in control. Solving such an issue will allow the design of cyber-agents capable of co-operatively interacting with people in order ... More
Exploiting nodes symmetries to control synchronization and consensus patterns in multiagent systemsMar 01 2016Sep 22 2016Most results on synchronization and consensus in multiagent systems are obtained under the assumption that some form of cooperation occurs between the nodes. Unfortunately, this assumption is not satisfied in many instances of systems from Nature and ... More
Observer design for piecewise smooth and switched systems via contraction theoryNov 08 2016The aim of this paper is to present the application of an approach to study contraction theory recently developed for piecewise smooth and switched systems. The approach that can be used to analyze incremental stability properties of so-called Filippov ... More
Deep learning control of artificial avatars in group coordination tasksJun 11 2019In many joint-action scenarios, humans and robots have to coordinate their movements to accomplish a given shared task. Lifting an object together, sawing a wood log, transferring objects from a point to another are all examples where motor coordination ... More
NetEvo: A computational framework for the evolution of dynamical complex networksDec 17 2009NetEvo is a computational framework designed to help understand the evolution of dynamical complex networks. It provides flexible tools for the simulation of dynamical processes on networks and methods for the evolution of underlying topological structures. ... More
Contraction analysis of switched Filippov systems via regularizationJul 25 2015Jun 27 2017We study incremental stability and convergence of switched (bimodal) Filippov systems via contraction analysis. In particular, by using results on regularization of switched dynamical systems, we derive sufficient conditions for convergence of any two ... More
Contraction analysis of switched Filippov systems via regularizationJul 25 2015Feb 24 2016In this paper we study incremental stability and convergence of switched (bimodal) Filippov systems via contraction analysis. In particular, by using results on regularization of switched dynamical systems we derive sufficient conditions for convergence ... More
Control of Painlevé Paradox in a Robotic SystemJul 09 2019The Painlev\'e paradox is a phenomenon that causes instability in mechanical systems subjects to unilateral constraints. While earlier studies were mostly focused on abstract theoretical settings, recent work confirmed the occurrence of the paradox in ... More
Design and Validation of a Virtual Player for Studying Interpersonal Coordination in the Mirror GameSep 19 2015The mirror game has been recently proposed as a simple, yet powerful paradigm for studying interpersonal interactions. It has been suggested that a virtual partner able to play the game with human subjects can be an effective tool to affect the underlying ... More
Interaction patterns and individual dynamics shape the way we move in synchronyJul 07 2016Jun 15 2017An important open problem in Human Behaviour is to understand how coordination emerges in human ensembles. This problem has been seldom studied quantitatively in the existing literature, in contrast to situations involving dual interaction. Here we study ... More
Modeling Joint Improvisation between Human and Virtual Players in the Mirror GameDec 17 2015Joint improvisation is observed to emerge spontaneously among humans performing joint action tasks, and has been associated with high levels of movement synchrony and enhanced sense of social bonding. Exploring the underlying cognitive and neural mechanisms ... More
Magnetization-control and transfer of spin-polarized Cooper pairs into a half-metal manganiteJun 01 2017Sep 11 2017The pairing state and critical temperature (T$_c$) of a thin s-wave superconductor (S) on two or more ferromagnets (F) are controllable through the magnetization-alignment of the F layers. Magnetization misalignment can lead to spin-polarized triplet ... More
Dynamic similarity promotes interpersonal coordination in joint-actionJul 01 2015Dec 22 2015Human movement has been studied for decades and dynamic laws of motion that are common to all humans have been derived. Yet, every individual moves differently from everyone else (faster/slower, harder/smoother etc). We propose here an index of such variability, ... More
Segal's spectral sequence in twisted equivariant K-theory for proper and discrete actionsJul 03 2013Jun 26 2015We use a spectral sequence developed by Graeme Segal in order to understand the twisted G-equivariant K-theory for proper and discrete actions. We show that the second page of this spectral sequence is isomorphic to a version of Bredon cohomology with ... More
Large spin-mixing conductance in highly Bi-doped Cu thin filmsJun 04 2018Jul 24 2018Spin Hall effect provides an efficient tool for the conversion of a charge current into a spin current, opening the possibility of producing pure spin currents in non-magnetic materials for the next generation of spintronics devices. In this sense, giant ... More
Improving SIEM capabilities through an enhanced probe for encrypted Skype traffic detectionNov 01 2017Nowadays, the Security Information and Event Management (SIEM) systems take on great relevance in handling security issues for critical infrastructures as Internet Service Providers. Basically, a SIEM has two main functions: i) the collection and the ... More
Intrinsic Paramagnetic Meissner Effect due to s-wave Odd-Frequency SuperconductivityMay 07 2016In 1933, Meissner and Ochsenfeld reported the expulsion of magnetic flux, the diamagnetic Meissner effect, from the interior of superconducting lead. This discovery was crucial in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. ... More
p-wave triggered superconductivity in single layer graphene on an electron-doped oxide superconductorFeb 06 2017Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional ... More
Fractional Spectral Moments for Digital Simulation of Multivariate Wind Velocity FieldsDec 16 2012In this paper, a method for the digital simulation of wind velocity fields by Fractional Spectral Moment function is proposed. It is shown that by constructing a digital filter whose coefficients are the fractional spectral moments, it is possible to ... More
A Parallel and Scalable Iterative Solver for Sequences of Dense Eigenproblems Arising in FLAPWMay 21 2013In one of the most important methods in Density Functional Theory - the Full-Potential Linearized Augmented Plane Wave (FLAPW) method - dense generalized eigenproblems are organized in long sequences. Moreover each eigenproblem is strongly correlated ... More
Post-Newtonian treatment of bar mode instability in rigidly rotating equilibrium configurations for polytropic starsMay 23 2002Jul 17 2002We determine the onset point of secular instability for the nonaxisymmetric bar mode in rigidly rotating equilibrium configurations in the Post-Newtonian approximation, in order to apply it to neutron stars. The treatment is based on a precedent Newtonian ... More
On Euler Emulation of Observer-Based Stabilizers for Nonlinear Time-Delay SystemsFeb 27 2018In this paper, we deal with the problem of the stabilization in the sample-and-hold sense, by emulation of continuous-time, observer-based, global stabilizers. Fully nonlinear time-delay systems are studied. Sufficient conditions are provided such that ... More
Dynamics of symmetric dynamical systems with delayed switchingApr 02 2008We study dynamical systems that switch between two different vector fields depending on a discrete variable and with a delay. When the delay reaches a problem-dependent critical value so-called event collisions occur. This paper classifies and analyzes ... More
Colocalization of coregulated genes: a steered molecular dynamics study of human chromosome 19Feb 20 2013The connection between chromatin nuclear organization and gene activity is vividly illustrated by the observation that transcriptional coregulation of certain genes appears to be directly influenced by their spatial proximity. This fact poses the more ... More
DDoS Attacks with Randomized Traffic Innovation: Botnet Identification Challenges and StrategiesJun 13 2016Sep 09 2016Distributed Denial-of-Service (DDoS) attacks are usually launched through the $botnet$, an "army" of compromised nodes hidden in the network. Inferential tools for DDoS mitigation should accordingly enable an early and reliable discrimination of the normal ... More
On polarized surfaces of low degree whose adjont bundles are not spannedSep 12 2000Smooth complex surfaces polarized with an ample and globally generated line bundle of degree three and four, such that the adjoint bundle is not globally generated, are considered. Scrolls of a vector bundle over a smooth curve are shown to be the only ... More
Fractional calculus approach to the statistical characterization of random variables and vectorsNov 17 2009Fractional moments have been investigated by many authors to represent the density of univariate and bivariate random variables in different contexts. Fractional moments are indeed important when the density of the random variable has inverse power-law ... More
On The Projective Normality of Smooth Surfaces of degree nineOct 07 1997We investigate the projective normality of smooth, linearly normal surfaces of degree 9. All non projectively normal surfaces which are not scrolls over a curve are classified. Results on the projective normality of surface scrolls are also given. One ... More
The Knuth-Robinson-Schensted correspondence and the Weak Polynomial Identities of $M_{1,1}(E)$May 02 2002In this paper it is proved that the ideal $I_w$ of the weak polynomial identities of the superalgebra $M_{1,1}(E)$ is generated by the proper polynomials $[x_1,x_2,x_3]$ and $[x_2,x_1][x_3,x_1][x_4,x_1]$. This is proved for any infinite field $F$ of characteristic ... More
The multidimensional truncated Moment Problem: Carathéodory Numbers from Hilbert FunctionsMar 02 2019Jun 28 2019In this paper we improve the bounds for the Carath\'eodory number, especially on algebraic varieties and with small gaps (not all monomials are present). We find that for every $\varepsilon>0$ and $d\in\mathbb{N}$ there is a $n\in\mathbb{N}$ such that ... More
On $(\le k)$-edges, crossings, and halving lines of geometric drawings of $K_n$Feb 24 2011Mar 16 2011Let $P$ be a set of points in general position in the plane. Join all pairs of points in $P$ with straight line segments. The number of segment-crossings in such a drawing, denoted by $\crg(P)$, is the \emph{rectilinear crossing number} of $P$. A \emph{halving ... 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 Coverage Based Decentralised Routing Algorithm for Vehicular Traffic NetworksAug 14 2015We present a simple yet effective routing strategy inspired by coverage control, which delays the onset of congestion on traffic networks, by introducing a control parameter. The routing algorithm allows a trade-off between the congestion level and the ... More
Ratiometric control of cell populations endowed with synthetic toggle switchesMar 22 2019We consider the problem of regulating by means of external control inputs the ratio of two cell populations. Specifically, we assume that these two cellular populations are composed of cells belonging to the same strain which embeds some bistable memory ... More
Analysis and control of genetic toggle switches subject to periodic multi-input stimulationJun 06 2018Sep 04 2018In this letter, we analyze a genetic toggle switch recently studied in the literature where the expression of two repressor proteins can be tuned by controlling two different inputs, namely the concentration of two inducer molecules in the growth medium ... More
Reconstructing directed and weighted topologies of phase-locked oscillator networksNov 10 2016The formalism of complex networks is extensively employed to describe the dynamics of interacting agents in several applications. The features of the connections among the nodes in a network are not always provided beforehand, hence the problem of appropriately ... More
Multiplex PI-Control for Consensus in Networks of Heterogeneous Linear AgentsJun 02 2015Dec 09 2015In this paper, we propose a multiplex proportional-integral approach, for solving consensus problems in networks of heterogeneous nodes dynamics affected by constant disturbances. The proportional and integral actions are deployed on two different layers ... More
Corner-Impact Bifurcations: a novel class of discontinuity-induced bifurcations in Cam-Follower SystemsNov 07 2007This paper is concerned with the analysis of a class of impacting systems of relevance in applications: cam-follower systems. We show that these systems, which can be modelled as discontinuously forced impact oscillators, can exhibit complex behaviour ... More
Self-organization of weighted networks for optimal synchronizabilityMay 27 2015We show that a network can self-organize its structure in a completely distributed manner in order to optimize its synchronizability whilst satisfying the local constraints: non-negativity of edge weights, and maximum weighted degree of nodes. A novel ... More
Contraction analysis of switched systems: the case of Caratheodory Systems and NetworksOct 04 2011In this paper we extend to a generic class of piecewise smooth dynamical systems a fundamental tool for the analysis of convergence of smooth dynamical systems: contraction theory. We focus on switched systems satisfying Caratheodory conditions for the ... More
Synchronizability and synchronization dynamics of weighed and unweighed scale free networks with degree mixingApr 13 2005Oct 09 2006We study the synchronizability and the synchronization dynamics of networks of nonlinear oscillators. We investigate how the synchronization of the network is influenced by some of its topological features such as variations of the power law exponent ... More
Synchronization of degree correlated physical networksJun 09 2005Jun 27 2005We propose that negative degree correlation among nodes in a network of nonlinear oscillators, often detected in real world networks, is motivated by its positive effects on synchronizability. In so doing, we use a novel methodology to characterise degree ... More
Effects of variations of load distribution on network performanceMar 31 2005This paper is concerned with the characterization of the relationship between topology and traffic dynamics. We use a model of network generation that allows the transition from random to scale free networks. Specifically, we consider three different ... More
Communication models with distributed transmission rates and buffer sizesApr 24 2006Apr 25 2006The paper is concerned with the interplay between network structure and traffic dynamics in a communications network, from the viewpoint of end-to-end performance of packet transfer. We use a model of network generation that allows the transition from ... More
Inverse proximity effect at superconductor-ferromagnet interfaces: Evidence for induced triplet pairing in the superconductorAug 05 2015Considerable evidence for proximity-induced triplet superconductivity on the ferromagnetic side of a superconductor-ferromagnet (S-F) interface now exists; however, the corresponding effect on the superconductor side has hardly been addressed. We have ... More
Magnetic exchange fields and domain wall superconductivity at an all-oxide superconductor / ferromagnet insulator interfaceApr 06 2018Sep 09 2018At a superconductor-ferromagnet (S/F) interface, the F layer can introduce a magnetic exchange field within the S layer, which acts to locally spin split the superconducting density of states. The effect of magnetic exchange fields on superconductivity ... More
Electric control of superconducting transition through a spin-orbit coupled interfaceJan 26 2016Aug 24 2016We demonstrate theoretically all-electric control of the superconducting transition temperature using a device comprised of a conventional superconductor, a ferromagnetic insulator, and semiconducting layers with intrinsic spin-orbit coupling. By using ... More
Peculiar Loci of Ample and Spanned Line BundlesJun 08 2003The bad locus and the rude locus of an ample and base point free linear system on a smooth complex projective variety are introduced and studied. The bad locus is defined as the set of points that force divisors through them to be reducible. The rude ... More
Merging black holes in young star clustersJan 03 2019Searching for distinctive signatures, which characterize different formation channels of binary black holes (BBHs), is a crucial step towards the interpretation of current and future gravitational wave detections. Here, we investigate the demography of ... More
Improved Control Strategies for Intermittent Contact Mode Atomic Force MicroscopesSep 16 2016Atomic force microscopes have proved to be fundamental research tools in many situations where a gentle imaging process is required, and in a variety of environmental conditions, such as the study of biological samples. Among the possible modes of operation, ... More
An algebraic metric for parametric stability analysis of power systemsMar 26 2015May 20 2015An analytic approximation for the critical clearing time (CCT) metric is derived from direct methods for power system stability. The formula has been designed to incorporate as many features of transient stability analysis as possible such as different ... More
Global entrainment of transcriptional systems to periodic inputsJun 30 2009This paper addresses the problem of giving conditions for transcriptional systems to be globally entrained to external periodic inputs. By using contraction theory, a powerful tool from dynamical systems theory, it is shown that certain systems driven ... More
Entrainment and Synchronization in Heterogeneous Networks of Haken-Kelso-Bunz (HKB) OscillatorsSep 02 2015In this paper we consider a heterogeneous network of Haken-Kelso-Bunz (HKB) nonlinear oscillators coupled through both linear and nonlinear interaction protocols. While some work exists on a system made up of only two nonlinearly coupled HKB oscillators ... More
Pinning-controllability of complex networksJan 04 2007Jan 30 2007We study the problem of controlling a general complex network towards an assigned synchronous evolution, by means of a pinning control strategy. We define the pinning-controllability of the network in terms of the spectral properties of an extended network ... More
Study of movement coordination in human ensembles via a novel computer-based set-upJul 29 2016Movement coordination in human ensembles has been studied little in the current literature. In the existing experimental works, situations where all subjects are connected with each other through direct visual and auditory coupling, and social interaction ... More
Extended Hybrid Model Reference Adaptive Control of Piecewise Affine SystemsMay 19 2015This note presents an extension to the adaptive control strategy presented in [1] able to counter eventual instability due to disturbances at the input of an otherwise $\mathcal{L}_2$ stable closed-loop system. These disturbances are due to the presence ... More
Two characterizations of simple circulant tournamentsJul 13 2015The \textit{acyclic disconnection} $\overrightarrow{\omega }(D)$ (resp. the \textit{directed triangle free disconnection } $\overrightarrow{\omega }_{3}(D)$) of a digraph $D$ is defined as the maximum possible number of connected components of the underlying ... More
Hyperbolicity, transitivity and the two-sided limit shadowing propertyJan 10 2013We explore the notion of two-sided limit shadowing property introduced by Pilyugin \cite{P1}. Indeed, we characterize the $C^1$-interior of the set of diffeomorphisms with such a property on closed manifolds as the set of transitive Anosov diffeomorphisms. ... More
Group actions on dg-manifolds and Exact Courant algebroidsOct 26 2010Oct 14 2012Let G be a Lie group acting by diffeomorphisms on a manifold M and consider the image of T[1]G and T[1]M, of G and M respectively, in the category of differential graded manifolds. We show that the obstruction to lift the action of T[1]G on T[1]M to an ... More
On the Classification of Pointed Fusion Categories up to weak Morita EquivalenceNov 17 2015Mar 11 2017A pointed fusion category is a rigid tensor category with finitely many isomorphism classes of simple objects which moreover are invertible. Two tensor categories $C$ and $D$ are weakly Morita equivalent if there exists an indecomposable right module ... More
The Weak Galerkin methods are rewritings of the Hybridizable Discontinuous Galerkin methodsDec 19 2018We establish that the Weak Galerkin methods are rewritings of the hybridizable discontinuous Galerkin methods.
Two-dimensional twistor manifolds and Teukolsky operatorsJul 04 2019The Teukolsky equations are currently the leading approach for analysing stability of linear massless fields propagating in rotating black holes. It has recently been shown that the geometry of these equations can be understood in terms of a connection ... More
Signature of magnetic-dependent gapless odd frequency states at superconductor/ferromagnet interfacesSep 09 2016The theory of superconductivity developed by Bardeen, Cooper and Schrieffer (BCS) explains the stabilization of electron pairs into a spin-singlet, even frequency, state by the formation of an energy gap within which the density of states is zero. At ... More
Average synaptic activity and neural networks topology: a global inverse problemOct 03 2013Mar 24 2014The dynamics of neural networks is often characterized by collective behavior and quasi-synchronous events, where a large fraction of neurons fire in short time intervals, separated by uncorrelated firing activity. These global temporal signals are crucial ... More
Cosmic-ray propagation with DRAGON2: II. Nuclear interactions with the interstellar gasNov 27 2017Jul 10 2018Understanding the isotopic composition of cosmic rays (CRs) observed near Earth represents a milestone towards the identification of their origin. Local fluxes contain all the known stable and long-lived isotopes, reflecting the complex history of primaries ... More
SAPSAM - Sparsely Annotated Pathological Sign Activation Maps - A novel approach to train Convolutional Neural Networks on lung CT scans using binary labels onlyFeb 06 2019Chronic Pulmonary Aspergillosis (CPA) is a complex lung disease caused by infection with Aspergillus. Computed tomography (CT) images are frequently requested in patients with suspected and established disease, but the radiological signs on CT are difficult ... More
Discrete phase-space approach to mutually orthogonal Latin squaresAug 28 2014Dec 22 2014We show there is a natural connection between Latin squares and commutative sets of monomials defining geometric structures in finite phase-space of prime power dimensions. A complete set of such monomials defines a mutually unbiased basis (MUB) and may ... More
Analogy between Jahn-Teller distortion and Rashba spin splitting, and Jahn-Teller counterpart of spin textureSep 11 2015Oct 12 2015In developing physical theories analogical reasoning has been found to be very powerful, as attested by a number of important historical examples. An analogy between two apparently different phenomena, once established, allows one to transfer information ... More
Substrate-supported triplet superconductivity in Dirac semimetalsSep 11 2018Stimulated by the success of graphene and its emerging Dirac physics, the quest for versatile and tunable electronic properties in atomically thin systems has led to the discovery of various chemical classes of 2D compounds. In particular, honeycomb lattices ... More
Persisting Meissner state and incommensurate phases of hard-core boson ladders in a fluxJun 12 2015Jun 25 2015The phase diagram of a half-filled hard core boson two-leg ladder in a flux is investigated by means of numerical simulations based on the Density Matrix Renormalization Group (DMRG) algorithm and bosonization. We calculate experimentally accessible observables ... More
Unconventional superconductivity in a doped quantum spin Hall insulatorNov 05 2018A monolayer of jacutingaite (Pt$_2$HgSe$_3$) has recently been identified as a novel quantum spin Hall insulator. By first-principles calculations, we study its Fermiology in the doped regime and unveil a type-I and type-II van Hove singularity for hole ... More
LES of the Sandia Flame D Using an FPV Combustion ModelFeb 01 2016The simulation of turbulent combustion phenomena is still an open problem in modern fluid dynamics. Considering the economical importance of hydrocarbon combustion in energy production processes, it is evident the need of an accurate tool with a relatively ... More
Achieving Large Multiplexing Gain in Distributed Antenna Systems via Cooperation with pCell TechnologyJan 22 2016In this paper we present pCellTM technology, the first commercial-grade wireless system that employs cooperation between distributed transceiver stations to create concurrent data links to multiple users in the same spectrum. First we analyze the per-user ... More
Time lapse, three dimensional in situ imaging of ice crystal growth in a colloidal silica suspensionMar 29 2018The freezing of colloidal suspensions is encountered in many natural and engineering processes such as the freezing of soils, food engineering, and cryobiology. It can also be used as a bio-inspired, versatile, and environmentally-friendly processing ... More
Implications of the Cosmic Ray Electron Spectrum and Anisotropy measured with Fermi-LATOct 01 2010Nov 19 2010The Fermi Large Area Telescope (LAT) collaboration recently released the updated results of the measurement of the cosmic ray electron (CRE) spectrum and published its first constraints on the CRE anisotropy. With respect to the previous Fermi-LAT results, ... More
Bridging the Gap between Individuality and Joint Improvisation in the Mirror GameNov 16 2016Extensive experiments in Human Movement Science suggest that solo motions are characterized by unique features that define the individuality or motor signature of people. While interacting with others, humans tend to spontaneously coordinate their movement ... More
Interaction patterns and individual dynamics shape the way we move in synchronyJul 07 2016Jul 18 2016The emergence of movement coordination in human ensembles has been seldom studied in the existing literature, in contrast to situations involving dual interaction. Here we investigate group synchronisation in a human ensemble where participants are asked ... More
A consistent interpretation of recent CR nuclei and electron spectraJan 10 2011We try to interpret the recently updated measurement of the cosmic ray electron (CRE) spectrum observed by Fermi-LAT, together with PAMELA data on positron fraction, in a single-component scenario adopting different propagation setups; we find that the ... More
Stellar, gas and dark matter content of barred galaxiesNov 14 2016We select a sample of galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) where galaxies are classified, through visual inspection, as hosting strong bars, weak bars or as unbarred galaxies, and make use of HI mass and kinematic information ... More
Equivariant principal bundles and their classifying spacesApr 17 2013Jan 09 2014We consider \Gamma-equivariant principal G-bundles over proper \Gamma-CW-complexes with prescribed family of local representations. We construct and analyze their classifying spaces for locally compact, second countable topological groups with finite ... More
Holonomy for Gerbes over OrbifoldsJul 09 2003In this paper we compute explicit formulas for the holonomy map for a gerbe with connection over an orbifold. We show that the holonomy descends to a transgression map in Deligne cohomology. We prove that this recovers both the inner local systems in ... More
Instability of asymptotically anti de Sitter black holes under Robin conditions at the timelike boundaryNov 10 2016Oct 25 2017The static region outside the event horizon of an asymptotically anti de Sitter black hole has a conformal timelike boundary $\mathscr{I}$ on which boundary conditions have to be imposed for the evolution of linear fields from initial data to be a well ... More
Topological Quantum Field Theories, Strings, and OrbifoldsMay 25 2006In this expository paper written for physicists and geometers we introduce the notions of TQFT and of orbifold. Then we survey the construction of TQFT's originating from orbifolds such as Chen-Ruan theory and Orbifold String Topology.
Classification of Pointed Fusion Categories of dimension 8 up to weak Morita EquivalenceJul 11 2017In this paper we give a complete classification of pointed fusion categories over $\mathbb{C}$ of global dimension 8. We first classify the equivalence classes of pointed fusion categories of dimension 8, and then we proceed to determine which of these ... More
An analysis of the Geodesic Distance and other comparative metrics for tree-like structuresJan 16 2019Graphs are interesting structures: extremely useful to depict real-life problems, extremely easy to understand given a sketch, extremely complicated to represent formally, extremely complicated to compare. Phylogeny is the study of the relations between ... More
Bounds on the cardinality of restricted sumsets in $\mathbb{Z}_{p}$Mar 26 2018In this paper we present a procedure which allows to transform a subset $A$ of $\mathbb{Z}_{p}$ into a set $ A'$ such that $ |2\hspace{0.15cm}\widehat{} A'|\leq|2\hspace{0.15cm}\widehat{} A | $, where $2\hspace{0.15cm}\widehat{} A$ is defined to be the ... More
A systematic construction of finite element commuting exact sequencesApr 30 2016We present a systematic construction of finite element exact sequences with a commuting diagram for the de Rham complex in one-, two- and three-space dimensions. We apply the construction in two-space dimensions to rediscover two families of exact sequences ... More
Topological properties of the unitary groupJul 07 2014We show that the strong operator topology, the weak operator topology and the compact-open topology agree on the space of unitary operators of a infinite dimensional separable Hilbert space. Moreover, we show that the unitary group endowed with any of ... More
Extended manifolds and extended equivariant cohomologyAug 13 2006Sep 27 2007We define the category of manifolds with extended tangent bundles, we study their symmetries and we consider the analogue of equivariant cohomology for actions of Lie groups in this category. We show that when the action preserves the splitting of the ... More
Physiological Aging as an Infinitesimally Ratcheted Random WalkJul 18 2017The distribution of a population throughout the physiological age of the individuals is very relevant information in population studies. It has been modeled by the Langevin and the Fokker- Planck equations. A major problem with these equations is that ... More
Stringy product on twisted orbifold K-theory for abelian quotientsJun 21 2007Feb 15 2008In this paper we present a model to calculate the stringy product on twisted orbifold K-theory of Adem-Ruan-Zhang for abelian complex orbifolds. In the first part we consider the non-twisted case on an orbifold presented as the quotient of a manifold ... More
Discussion of "Objective Priors: An Introduction for Frequentists" by M. GhoshAug 17 2011Discussion of "Objective Priors: An Introduction for Frequentists" by M. Ghosh [arXiv:1108.2120]