Results for "Filippo Cavallo"

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The concordance invariant tau in link grid homologyDec 29 2015Feb 08 2018We introduce a generalization of the Ozsv\'ath-Szab\'o $\tau$-invariant to links by studying a filtered version of link grid homology. We prove that this invariant remains unchanged under strong concordance and we show that it produces a lower bound for ... More
On the slice genus and some concordance invariants of linksMar 05 2014Sep 10 2014We introduce a new class of links for which we give a lower bound for the slice genus $g_*$, using the generalized Rasmussen invariant. We show that this bound, in some cases, allows one to compute $g_*$ exactly; in particular, we compute $g_*$ for torus ... More
A family of polycyclic groups over which the uniform conjugacy problem is NP-completeMar 17 2014Oct 20 2014In this paper we study the conjugacy problem in polycyclic groups. Our main result is that we construct polycyclic groups $G_n$ whose conjugacy problem is at least as hard as the subset sum problem with $n$ indeterminates. As such, the conjugacy problem ... More
Secret Sharing using Non-Commutative Groups and the Shortlex OrderNov 27 2013Dec 15 2014In this paper we review the Habeeb-Kahrobaei-Shpilrain secret sharing scheme and introduce a variation based on the shortlex order on a free group. Drawing inspiration from adjustments to classical schemes, we also present a method that allows for the ... More
A general unified framework for interval pairwise comparison matricesNov 26 2017Interval Pairwise Comparison Matrices have been widely used to account for uncertain statements concerning the preferences of decision makers. Several approaches have been proposed in the literature, such as multiplicative and fuzzy interval matrices. ... More
Cleaning tasks knowledge transfer between heterogeneous robots: a deep learning approachMar 13 2019Nowadays, autonomous service robots are becoming an important topic in robotic research. Differently from typical industrial scenarios, with highly controlled environments, service robots must show an additional robustness to task perturbations and changes ... More
Percolation in real interdependent networksMar 16 2015The function of a real network depends not only on the reliability of its own components, but is affected also by the simultaneous operation of other real networks coupled with it. Robustness of systems composed of interdependent network layers has been ... More
A paradox in community detectionDec 16 2013May 06 2014Recent research has shown that virtually all algorithms aimed at the identification of communities in networks are affected by the same main limitation: the impossibility to detect communities, even when these are well-defined, if the average value of ... More
In science "there is no bad publicity": Papers criticized in comments have high scientific impactSep 22 2012Nov 08 2012Comments are special types of publications whose aim is to correct or criticize previously published papers. For this reason, comments are believed to make commented papers less worthy or trusty to the eyes of the scientific community, and thus predestined ... More
Detectability of communities in heterogeneous networksJun 05 2013Jul 04 2013Communities are fundamental entities for the characterization of the structure of real networks. The standard approach to the identification of communities in networks is based on the optimization of a quality function known as "modularity". Although ... More
A bound on the charm chromo-EDM and its implicationsDec 09 2013Sep 09 2014We derive bounds on the electric and chromo-electric dipole moments of the charm quark. The second one turns out to be particularly strong, and we quantify its impact on models that allow for a sizeable flavour violation in the up quark sector, like flavour ... More
Cosmological perturbations from varying masses and couplingsNov 07 2003May 03 2004We study the evolution of perturbations during the domination and decay of a massive particle species whose mass and decay rate are allowed to depend on the expectation value of a light scalar field. We specialize in the case where the light field is ... More
Intertwining operators of the quantum Teichmüller spaceOct 19 2016In arXiv:0707.2151 the authors introduced the theory of local representations of the quantum Teichm\"uller space $\mathcal{T}^q_S$ ($q$ being a fixed primitive $N$-th root of $(-1)^{N + 1}$) and they studied the behaviour of the intertwining operators ... More
The homology of the Milnor fiber for classical braid groupsNov 17 2005May 21 2009In this paper we compute the homology of the braid groups, with coefficients in the module Z[q^+-1] given by the ring of Laurent polynomials with integer coefficients and where the action of the braid group is defined by mapping each generator of the ... More
Two-time Green's functions and spectral density method in nonextensive quantum statistical mechanicsOct 30 2007Sep 07 2008We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multipliers representation, the $q$-spectral properties and the methods for a direct calculation of ... More
Spectral density method in quantum nonextensive thermostatistics and magnetic systems with long-range interactionsSep 29 2005Dec 07 2005Motived by the necessity of explicit and reliable calculations, as a valid contribution to clarify the effectiveness and, possibly, the limits of the Tsallis thermostatistics, we formulate the Two-Time Green Functions Method in nonextensive quantum statistical ... More
The neutron EDM vs up and charm flavour violationMay 21 2014We derive a strong bound on the chromo-electric dipole moment of the charm quark, and we quantify its impact on models that allow for a sizeable flavour violation in the up quark sector. In particular we show how the constraints coming from the charm ... More
On the conservation of second-order cosmological perturbations in a scalar field dominated universeNov 16 2004Feb 18 2005We discuss second-order cosmological perturbations on super-Hubble scales, in a scalar field dominated universe, such as during single field inflation. In this contest we show that the gauge-invariant curvature perturbations defined on uniform density ... More
M2-Brane Superalgebra from Bagger-Lambert TheoryJun 02 2008It is known that the M2-brane worldvolume superalgebra includes two p-form central charges that encode the M-theory intersections involving M2-branes. In this paper we show by explicit computation that the Bagger-Lambert Lagrangian realizes the M2-brane ... More
Nonlinear Bosonization and Refermionization in One Dimension with the Keldysh Functional IntegralOct 25 2016We develop a self-contained approach to bosonization and refermionization using the Keldysh functional integral. Starting from fermionic particles, we bosonize the system and obtain a description in terms of the Tomonaga-Luttinger liquid, with, in addition, ... More
Underestimating extreme events in power-law behavior due to machine-dependent cutoffsApr 30 2014Nov 03 2014Power-law distributions are typical macroscopic features occurring in almost all complex systems observable in nature. As a result, researchers in quantitative analyses must often generate random synthetic variates obeying power-law distributions. The ... More
Driving interconnected networks to supercriticalityNov 27 2013Apr 22 2014Networks in the real world do not exist as isolated entities, but they are often part of more complicated structures composed of many interconnected network layers. Recent studies have shown that such mutual dependence makes real networked systems potentially ... More
Human Activity in the WebMar 17 2009Jul 27 2009The recent information technology revolution has enabled the analysis and processing of large-scale datasets describing human activities. The main source of data is represented by the Web, where humans generally use to spend a relevant part of their day. ... More
Six Years of Gamma Ray Burst Observations with BeppoSAXJul 30 2004I give a summary of the prompt X-/gamma-ray detections of Gamma Ray Bursts (GRBs) with the BeppoSAX satellite and discuss some significant results obtained from the study of the prompt emission of these GRBs obtained with the BeppoSAX Gamma Ray Burst ... More
Nonlinearity in oscillating bridgesJun 01 2013We first recall several historical oscillating bridges that, in some cases, led to collapses. Some of them are quite recent and show that, nowadays, oscillations in suspension bridges are not yet well understood. Next, we survey some attempts to model ... More
Transport and Concentration Problems with Interaction EffectsAug 11 2005After presenting an overview about variational problems on probability measures for functionals involving transport costs and extra terms encouraging or discouraging concentration, we look for optimality conditions, regularity properties and explicit ... More
Quantum Bayesian methods and subsequent measurementsAug 01 2005Aug 29 2005After a derivation of the quantum Bayes theorem, and a discussion of the reconstruction of the unknown state of identical spin systems by repeated measurements, the main part of this paper treats the problem of determining the unknown phase difference ... More
Quantum interference and Bayes theoremJan 10 2006This note is a comment on the "quantum interferometry" section of Reference [1]. It points out that the methods of that section can be applied to more general states than the ones that are discussed in Ref. [1].
Gas Accretion via Condensation and FountainsDec 01 2016For most of their lives, galaxies are surrounded by large and massive coronae of hot gas, which constitute vast reservoirs for gas accretion. This Chapter describes a mechanism that allows star-forming disc galaxies to extract gas from their coronae. ... More
Regular patterns in the information flow of local dephasing channelsDec 02 2016Consider local dephasing processes of a qubit that interacts with a structured reservoir of frequency modes or a thermal bath, with Ohmic-like spectral density (SD). It is known that non-Markovian evolution appears uniquely above a temperature-dependent ... More
On the cohomology of Artin groups in local systems and the associated Milnor fiberMay 15 2004Let W be a finite irreducible Coxeter group and let X_W be the classifying space for G_W, the associated Artin group. If A is a commutative unitary ring, we consider the two local systems L_q and L_q' over X_W, respectively over the modules A[q,q^{-1}] ... More
Infinitesimal deformations of restricted simple Lie algebras IIFeb 16 2007Nov 17 2008We compute the infinitesimal deformations of two families of restricted simple Lie algebras: the contact and the Hamiltonian algebras.
A few remarks on the octopus inequality and Aldous' spectral gap conjectureOct 23 2013Nov 08 2013A conjecture by D. Aldous, which can be formulated as a statement about the first nontrivial eigenvalue of the Laplacian of certain Cayley graphs on the symmetric group generated by transpositions, has been recently proven by Caputo, Liggett and Richthammer. ... More
On the eigenvalues of Cayley graphs on the symmetric group generated by a complete multipartite set of transpositionsFeb 04 2009Jan 14 2010Given a finite simple graph $\cG$ with $n$ vertices, we can construct the Cayley graph on the symmetric group $S_n$ generated by the edges of $\cG$, interpreted as transpositions. We show that, if $\cG$ is complete multipartite, the eigenvalues of the ... More
Simple finite group schemes and their infinitesimal deformationsNov 17 2008Aug 10 2010We show that the classification of simple finite group schemes over an algebraically closed field reduces to the classification of abstract simple finite groups and of simple restricted Lie algebras in positive characteristic. Both these two simple objects ... More
On the spectral gap of some Cayley graphs on the Weyl group $W(B_n)$Jul 31 2018The Laplacian of a (weighted) Cayley graph on the Weyl group $W(B_n)$ is a $N\times N$ matrix with $N = 2^n n!$ equal to the order of the group. We show that for a class of (weighted) generating sets, its spectral gap (lowest nontrivial eigenvalue), is ... More
{ Euclidean, Metric, and Wasserstein } Gradient Flows: an overviewSep 13 2016This is an expository paper on the theory of gradient flows, and in particular of those PDEs which can be interpreted as gradient flows for the Wasserstein metric on the space of probability measures (a distance induced by optimal transport). The starting ... More
Gauge Theory Wilson Loops and Conformal Toda Field TheoryMar 05 2010Mar 15 2010The partition function of a family of four dimensional N=2 gauge theories has been recently related to correlation functions of two dimensional conformal Toda field theories. For SU(2) gauge theories, the associated two dimensional theory is A_1 conformal ... More
Recent Results on Gamma-Ray Bursts with the Bepposax SatelliteFeb 12 1998Recent results on Gamma-Ray Bursts obtained with the X-ray Astronomy satellite BeppoSAX are reviewed. Main emphasis is given to the GRBs simultaneously detected with the Gamma-Ray Burst Monitor (40-700 keV) and the Wide Field Cameras (1.5-26 keV). These ... More
On the nature of the Extremely Red GalaxiesJan 29 2002We present a method based on two broad-band colors to investigate the nature of the Extremely Red Objects (EROs), i.e., the galaxies selected to have very red optical-to-infrared colors. Dusty starburst and old ellipticals at redshifts between 1 and 2 ... More
A U(2)^3 flavour symmetry in SupersymmetryJun 08 2012Sep 20 2012A U(2)^3 flavour symmetry acting on the first two generations of quarks partially explains the hierarchies of the yukawa couplings, and provides a natural embedding for Supersymmetry with heavier first two generations, where collider constraints are not ... More
Epsilon_K in the Standard Model and the kaon phase conventionsJun 02 2016The parameter epsilon_K, that quantifies CP violation in kaon mixing, is the observable setting the strongest constraints on new physics with a generic flavour and CP structure. While its experimental uncertainty is at the half percent level, the theoretical ... More
Higgs and flavour as doors to new physicsSep 29 2015Apr 05 2016A natural solution to the hierarchy problem of the Fermi scale motivates signals of New Physics at current and near future experiments. After a critical synthesis of this general motivation, we concentrate our attention on the interplay between LHC searches ... More
Universally Optimal Noisy Quantum Walks on Complex NetworksDec 06 2013Apr 16 2014Transport properties play a crucial role in several fields of science, as biology, chemistry, sociology, information science, and physics. The behavior of many dynamical processes running over complex networks is known to be closely related to the geometry ... More
Transformation of intermediate times in the decays of moving unstable quantum systems via the exponential modesFeb 14 2019The transformation of canonical decay laws of moving unstable quantum systems is studied by approximating, over intermediate times, the decay laws at rest with superpositions of exponential modes via the Prony analysis. The survival probability $\mathcal{P}_p(t)$, ... More
The complexity of the embeddability relation between torsion-free abelian groups of uncountable sizeApr 11 2017Aug 03 2018We prove that for every uncountable cardinal $\kappa$ such that $\kappa^{<\kappa}=\kappa$, the quasi-order of embeddability on the $\kappa$-space of $\kappa$-sized graphs Borel reduces to the embeddability on the $\kappa$-space of $\kappa$-sized torsion-free ... More
Restricted infinitesimal deformations of restricted simple Lie algebrasMay 06 2007Nov 16 2011We compute the restricted infinitesimal deformations of the restricted simple Lie algebras over an algebraically closed field of characteristic different from 2 and 3.
The key role of BeppoSAX in the GRB historyFeb 16 2019Twenty years have already been elapsed from the BeppoSAX discovery of the first afterglow of a Gamma Ray Burst (GRB) on February 28, 1997. Thanks to this discovery, it was possible to unveil the 30 year mystery about GRB origin: GRBs are huge explosions ... More
The Classical Spectral Density Method at Work: The Heisenberg FerromagnetFeb 19 2006In this article we review a less known unperturbative and powerful many-body method in the framework of classical statistical mechanics and then we show how it works by means of explicit calculations for a nontrivial classical model. The formalism of ... More
Thermodynamic properties of a classical d-dimensional spin-S Heisenberg ferromagnet with long-range interactions via the spectral density methodJun 26 2003The thermodynamic properties of a classical d-dimensional spin-S Heisenberg ferromagnet, with long-range interactions decaying as $r^{-p}$ and in the presence of an external magnetic field, is investigated by means of the spectral density method in the ... More
Quasi-periodic solutions for quasi-linear generalized KdV equationsJul 09 2016We prove the existence of Cantor families of small amplitude, linearly stable, quasi-periodic solutions of quasi-linear autonomous Hamiltonian generalized KdV equations. We consider the most general quasi-linear quadratic nonlinearity. The proof is based ... More
Who is the best player ever? A complex network analysis of the history of professional tennisJan 20 2011Feb 10 2011We consider all matches played by professional tennis players between 1968 and 2010, and, on the basis of this data set, construct a directed and weighted network of contacts. The resulting graph shows complex features, typical of many real networked ... More
Continuum Approach to Non-equilibrium Quantum Functional IntegralFeb 26 2015Standard derivations of the functional integral in non-equilibrium quantum field theory are based on the discrete time representation. In this work we derive the non-equilibrium functional integral for non-interacting bosons and fermions using a continuum ... More
X-Ray Observations of Gamma-Ray Burst AfterglowsJun 25 2004The discovery by the BeppoSAX satellite of X-ray afterglow emission from the gamma-ray burst which occurred on 28 February 1997 produced a revolution in our knowledge of the gamma-ray burst phenomenon. Along with the discovery of X-ray afterglows, the ... More
The metallicity properties of long-GRB hostsOct 05 2011The recently-discovered Fundamental Metallicity Relation (FMR), which is the tight dependence of metallicity on both mass and SFR, proves to be a very useful tool to study the metallicity properties of various classes of galaxies. We have used the FMR ... More
Flavour and Higgs physics near the Fermi scaleDec 05 2013After a discussion of the hierarchy problem of the Fermi scale, we study the flavour and Higgs boson(s) phenomenology of new physics close to it, both in general and in the specific cases of Supersymmetry and composite Higgs models. First, we promote ... More
Generating cosmological perturbations with mass variationsMar 08 2005We study the possibility that large scale cosmological perturbations have been generated during the domination and decay of a massive particle species whose mass depends on the expectation value of a light scalar field. We discuss the constraints that ... More
Storing Quantum Information via Atomic Dark ResonancesJan 26 2010In this thesis, after a brief review of some concepts of Quantum Optics, we analyze a three-level atomic system in the conditions of electromagnetically induced transparency (EIT), and we investigate the propagation of a gaussian pulse along a cigar-shaped ... More
Una valutazione di copertura, qualita' ed efficienza dei servizi sanitari regionali tra 2010 e 2013Nov 23 2018Dec 04 2018An application of Multiplicative Non-Parametric Corporate Performance Model (based on Data Envelopment Analysis) by Emrouznejad and Cabanda is here presented and applied so as to evaluate effectiveness, efficiency and quality of Regional Health Systems ... More
Salvetti complex, spectral sequences and cohomology of Artin groupsSep 15 2013The aim of this short survey is to give a quick introduction to the Salvetti complex as a tool for the study of the cohomology of Artin groups. In particular we show how a spectral sequence induced by a filtration on the complex provides a very natural ... More
On the peripheral subgroups of irreducible 3-manifold groups and acylindrical splittingsMay 17 2017Oct 19 2017We survey the problem of separation under conjugacy and malnormality of the abelian peripheral subgroups of an orientable, irreducible $3$-manifold $X$. We shall focus on the relation between this problem and the existence of acylindrical splittings of ... More
Restricted simple Lie algebras and their infinitesimal deformationsFeb 25 2007In this expository paper, we first review the classification of the restricted simple Lie algebras in characteristic different from 2 and 3 and then we describe their infinitesimal deformations. We conclude by indicating some possible application to the ... More
Deformations of the restricted Melikian Lie algebraFeb 20 2007Mar 07 2008We compute the infinitesimal deformations of the restricted Melikian Lie algebra in characteristic 5.
Projectively induced rotation invariant Kähler metricsJul 25 2016Dec 03 2016We classify K\"ahler-Einstein manifolds which admit a K\"ahler immersion into a finite dimensional complex projective space endowed with the Fubini-Study metric, whose codimention is not greater than 3 and whose metric is rotation invariant.
Projectively induced rotation invariant Kähler metricsJul 25 2016We classify K\"ahler-Einstein manifolds which admit a K\"ahler immersion into a finite dimensional complex projective space endowed with the Fubini-Study metric, whose codimention is not greater than 3 and whose metric is rotation invariant.
Margulis Lemma, entropy and free productsApr 07 2012May 24 2012We prove a Margulis' Lemma \`a la Besson Courtois Gallot, for manifolds whose fundamental group is a nontrivial free product A*B, without 2-torsion. Moreover, if A*B is torsion-free we give a lower bound for the homotopy systole in terms of upper bounds ... More
Angular and polarization correlations in two--photon decay of hyperfine 2s states in hydrogenlike ionsMar 29 2012The angular and polarization properties of the photon pair emitted in the two--photon decay of $2s$ hyperfine states in hydrogenlike ions are investigated within the relativistic Dirac framework and second order perturbation theory. The studied transitions ... More
Nanoscale artificial intelligence: creating artificial neural networks using autocatalytic reactionsFeb 29 2016A general methodology is proposed to engineer a system of interacting components (particles) which is able to self-regulate their concentrations in order to produce any prescribed output in response to a particular input. The methodology is based on the ... More
Predicting percolation thresholds in networksDec 11 2014Jan 15 2015We consider different methods, that do not rely on numerical simulations of the percolation process, to approximate percolation thresholds in networks. We perform a systematic analysis on synthetic graphs and a collection of 109 real networks to quantify ... More
Universality, limits and predictability of gold-medal performances at the Olympic GamesMar 14 2012Jul 13 2012Inspired by the Games held in ancient Greece, modern Olympics represent the world's largest pageant of athletic skill and competitive spirit. Performances of athletes at the Olympic Games mirror, since 1896, human potentialities in sports, and thus provide ... More
Diffusion and Aggregation in an Agent Based Model of Stock Market FluctuationsJun 29 2000We describe a new model to simulate the dynamic interactions between market price and the decisions of two different kind of traders. They possess spatial mobility allowing to group together to form coalitions. Each coalition follows a strategy chosen ... More
Secure Identification in The Isolated Qubits ModelOct 24 2015Oblivious transfer is a powerful cryptographic primitive that is complete for secure multi-party computation. In oblivious transfer protocols a user sends one or more messages to a receiver, while the sender remains oblivious as to which messages have ... More
A Spectra comparison theorem and its applicationsJan 07 2013We give a sharp comparison between the spectra of two Riemannian manifolds (Y,g) and (X,g_0) under the following assumptions: (X,g_0) has bounded geometry, (Y,g) admits a continuous Gromov-Hausdorff {\epsilon}-approximation onto (X,g_0) of non zero absolute ... More
Index and nullity of the Gauss map of the Costa-Hoffman-Meeks surfacesJun 11 2008The aim of this work is to extend the results of S. Nayatani about the index and the nullity of the Gauss map of the Costa-Hoffman-Meeks surfaces for values of the genus bigger than 37. That allows us to state that these minimal surfaces are non degenerate ... More
Infinitesimal deformations of restricted simple Lie algebras IDec 29 2006Jul 02 2008We compute the infinitesimal deformations of two families of restricted simple modular Lie algebras of Cartan type: the Witt-Jacobson and the Special Lie algebras.
Cayley graphs on the symmetric group generated by initial reversals have unit spectral gapApr 11 2009Nov 11 2009In a recent paper Gunnells, Scott and Walden have determined the complete spectrum of the Schreier graph on the symmetric group corresponding to the Young subgroup $S_{n-2}\times S_2$ and generated by initial reversals. In particular they find that the ... More
Universality of scholarly impact metricsMay 27 2013Sep 24 2013Given the growing use of impact metrics in the evaluation of scholars, journals, academic institutions, and even countries, there is a critical need for means to compare scientific impact across disciplinary boundaries. Unfortunately, citation-based metrics ... More
The concordance invariant $τ$ in link grid homologyDec 29 2015We introduce a generalization of the Ozsv\'ath-Szab\'o $\tau$-invariant to links by studying a filtered version of link grid homology. We prove that this invariant remains unchanged under strong concordance and we show that it produces a lower bound for ... More
The Production of Sodium and Aluminum in Globular Cluster Red Giant StarsApr 04 1996We study the production of Na and Al around the hydrogen shell of two red-giant sequences of different metallicity in order to explain the abundance variations seen in globular cluster stars in a mixing scenario. Using detailed stellar models together ... More
On Bennequin type inequalities for links in tight contact 3-manifoldsJan 02 2018Mar 27 2018We prove that a version of the Thurston-Bennequin inequality holds for Legendrian and transverse links in a rational homology contact 3-sphere $(M,\xi)$, whenever $\xi$ is tight. More specifically, we show that the self-linking number of a transverse ... More
Redundant interdependencies boost the robustness of multilayer networksOct 17 2016In the standard model of percolation on multilayer networks, a node is functioning only if its copies in all layers are simultaneously functioning. According to this model, a multilayer network becomes more and more fragile as the number of layers increases. ... More
Analysis of bibliometric indicators for individual scholars in a large data setApr 04 2013Citation numbers and other quantities derived from bibliographic databases are becoming standard tools for the assessment of productivity and impact of research activities. Though widely used, still their statistical properties have not been well established ... More
Accretion by the GalaxyOct 14 2011Cosmology requires at least half of the baryons in the Universe to be in the intergalactic medium, much of which is believed to form hot coronae around galaxies. Star-forming galaxies must be accreting from their coronae. HI observations of external galaxies ... More
Explosive percolation: a numerical analysisNov 18 2009Mar 23 2010Percolation is one of the most studied processes in statistical physics. A recent paper by Achlioptas et al. [Science 323, 1453 (2009)] has shown that the percolation transition, which is usually continuous, becomes discontinuous ("explosive") if links ... More
Induced representations and harmonic analysis on finite groupsApr 11 2013Given a finite group $G$ and a subgroup $K$, we study the commutant of $\text{Ind}_K^G\theta$, where $\theta$ is an irreducible $K$-representation. After a careful analysis of Frobenius reciprocity, we are able to introduce an orthogonal basis in such ... More
Percolation in real multiplex networksOct 27 2016We present an exact mathematical framework able to describe site-percolation transitions in real multiplex networks. Specifically, we consider the average percolation diagram valid over an infinite number of random configurations where nodes are present ... More
Harmonic analysis on a finite homogeneous spaceJan 19 2007In this paper, we study harmonic analysis on finite homogeneous spaces whose associated permutation representation decomposes with multiplicity. After a careful look at Frobenius reciprocity and transitivity of induction, and the introduction of three ... More
On a nonlinear nonlocal hyperbolic system modeling suspension bridgesJan 15 2015We suggest a new model for the dynamics of a suspension bridge through a system of nonlinear nonlocal hyperbolic differential equations. The equations are of second and fourth order in space and describe the behavior of the main components of the bridge: ... More
Higher order linear parabolic equationsDec 20 2012We first highlight the main differences between second order and higher order linear parabolic equations. Then we survey existing results for the latter, in particular by analyzing the behavior of the convolution kernels. We illustrate the updated state ... More
Non-Gaussianities in two-field inflationMar 29 2006May 18 2006We study the bispectrum of the curvature perturbation on uniform energy density hypersurfaces in models of inflation with two scalar fields evolving simultaneously. In the case of a separable potential, it is possible to compute the curvature perturbation ... More
Holographic Wilson LoopsApr 03 2006Dec 10 2006We show that all half-BPS Wilson loop operators in N=4 SYM -- which are labeled by Young tableaus -- have a gravitational dual description in terms of D5-branes or alternatively in terms of D3-branes in AdS_5xS^5. We prove that the insertion of a half-BPS ... More
Abrupt transition in the structural formation of interconnected networksJul 17 2013Our current world is linked by a complex mesh of networks where information, people and goods flow. These networks are interdependent each other, and present structural and dynamical features different from those observed in isolated networks. While examples ... More
Bialgebraic Semantics for Logic ProgrammingFeb 21 2015Mar 27 2015Bialgebrae provide an abstract framework encompassing the semantics of different kinds of computational models. In this paper we propose a bialgebraic approach to the semantics of logic programming. Our methodology is to study logic programs as reactive ... More
Prediction of extreme events in the OFC model on a small world networkApr 27 2010We investigate the predictability of extreme events in a dissipative Olami-Feder-Christensen model on a small world topology. Due to the mechanism of self-organized criticality, it is impossible to predict the magnitude of the next event knowing previous ... More
A new approach to characterize qubit channelsFeb 20 2008We analyze qubit channels by exploiting the possibility of representing two-level quantum systems in terms of characteristic functions. To do so, we use functions of non-commuting variables (Grassmann variables), defined in terms of generalized displacement ... More
Rotating Solutions of Non-relativistic String TheoryNov 22 2004Jul 28 2005We construct classical rotating solutions of Non-relativistic String Theory. The relation among the energy and angular momenta for these solutions is of the type E=J^2. Some of the solutions saturate a BPS bound for the energy, they are 1/4 BPS supersymmetric ... More
Connecting Dream Networks Across CulturesFeb 10 2014Many species dream, yet there remain many open research questions in the study of dreams. The symbolism of dreams and their interpretation is present in cultures throughout history. Analysis of online data sources for dream interpretation using network ... More
Demonstration of a Degenerate Band Edge in Periodically-Loaded Circular WaveguidesFeb 23 2015We demonstrate the existence of a special degeneracy condition, called degenerate band edge (DBE), between two Bloch modes in periodically loaded circular all-metallic waveguides at microwave frequencies. The DBE condition has been associated with a dramatic ... More
Automated words stability and languages phylogenyNov 17 2009Dec 05 2009The idea of measuring distance between languages seems to have its roots in the work of the French explorer Dumont D'Urville (D'Urville 1832). He collected comparative words lists of various languages during his voyages aboard the Astrolabe from 1826 ... More
Measures of lexical distance between languagesDec 04 2009Dec 09 2009The idea of measuring distance between languages seems to have its roots in the work of the French explorer Dumont D'Urville \cite{Urv}. He collected comparative words lists of various languages during his voyages aboard the Astrolabe from 1826 to 1829 ... More