Results for "Jacopo Fumagalli"

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Non-local formulation of ghost-free bigravity theoryJul 21 2014We study the ghost-free bimetric theory of Hassan and Rosen, with parameters $\beta_i$ such that a flat Minkowski solution exists for both metrics. We show that, expanding around this solution and eliminating one of the two metrics with its own equation ... More
Renormalization Group independence of Cosmological AttractorsNov 15 2016The large class of inflationary models known as $\alpha$- and $\xi$-attractors give identical predictions at tree level (at leading order in inverse power of the number of efolds). Working with the renormalization group improved action, we show that these ... More
UV (in)sensitivity of Higgs inflationFeb 23 2016Apr 27 2016The predictions of Standard Model Higgs inflation are in excellent agreement with the Planck data, without the need for new fields. However, consistency of the theory requires the presence of (unknown) threshold corrections. These modify the running of ... More
Tensor power spectrum and disformal transformationsOct 26 2016In a general effective theory description of inflation a disformal transformation can be used to set the tensor sound speed to one. After the transformation, the tensor power spectrum then automatically only depends on the Hubble parameter. We show that ... More
Metal abundances in the high-redshift intergalactic mediumDec 18 2013Twenty years of high-resolution spectroscopy at the 8-10 m class telescopes have drastically expanded our view of the gas-phase metallicity in the z>2 universe. This contribution briefly summarizes how these studies reveal a widespread metal pollution ... More
A free-boundary problem with moving contact pointsJul 01 2017This paper concerns the theoretical and numerical analysis of a free boundary problem for the Laplace equation, with a curvature condition on the free boundary. This boundary is described as the graph of a function, and contact angles are imposed at the ... More
On the class of continuous images of non-commutative Valdivia compactaMar 11 2016We investigate the class of continuous images of non-commutative Valdivia compact spaces, in particular its subclass of weakly non-commutative Cor- son countably compact spaces. A key tool is the study of non-commutative Corson countably compact spaces ... More
Comments on the Chiral Symmetry Breaking in Soft Wall Holographic QCDDec 14 2009Dec 23 2009In this paper we describe qualitatively some aspects of the holographic QCD. Inspired by a successfull 4D description, we try to separate the Confinement and the Chiral Symmetry Breaking dynamics. We also discuss the realization of the baryons as skyrmions ... More
Unstable BlowupsFeb 06 2007Nov 12 2007Let (X,L) be a polarised manifold. We show that K-stability and asymptotic Chow stability of the blowup of X along a 0-dimensional cycle are closely related to Chow stability of the cycle itself, for polarizations making the exceptional divisors small. ... More
Spherical orbit closures in simple projective spaces and their normalizationsJul 07 2009Oct 19 2010Let G be a simply connected semisimple algebraic group over an algebraically closed field k of characteristic 0 and let V be a rational simple G-module of finite dimension. If G/H \subset P(V) is a spherical orbit and if X is its closure, then we describe ... More
Instantons and quark zero modes in AdS/QCDSep 16 2009In this paper the quark zero modes creation effect is studied in the context of the AdS/QCD approach. This effect is generated, in presence of instantons, by a new that can be added in the bulk.
Review of the EFT treatment of quarkonium at finite temperatureMar 26 2013Apr 24 2013Heavy quarkonium is one of the most investigated probes of the medium produced in heavy-ion collisions. In the past few years progress has been made in the description of its in-medium dynamics from QCD. Non-relativistic EFTs in particular allow one to ... More
Framed symplectic sheaves on surfacesApr 05 2016Apr 28 2016A framed symplectic sheaf on a smooth projective surface $X$ is a torsion-free sheaf $E$ together with a trivialization on a divisor $D\subseteq X$ and a morphism $\Lambda^{2}E\rightarrow\mathcal{O}_{X}$ satisfying some additional conditions. We construct ... More
A category-theoretic version of the identity type weak factorization systemNov 29 2014Gambino and Garner proved that the syntactic category of a dependent type theory with identity types can be endowed with a weak factorization system structure, called identity type weak factorization system. In this paper we consider an enrichment of ... More
Energy loss at NLO in a high-temperature Quark-Gluon PlasmaJan 25 2016We present an extension of the Arnold-Moore-Yaffe kinetic equations for jet energy loss to NLO in the strong coupling constant. A novel aspect of the NLO analysis is a consistent description of wider-angle bremsstrahlung (semi-collinear emissions), which ... More
Next-to-leading order thermal photon production in a weakly-coupled plasmaApr 02 2014We summarize the recent determination to next-to-leading order of the thermal photon rate at weak coupling. We emphasize how it can be expressed in terms of gauge-invariant condensates on the light cone, which are amenable to novel sum rules and Euclidean ... More
A brief review of the theory of charmonium suppression in heavy ion collisionsNov 28 2013A brief overview of the theory of charmonium suppression in heavy ion collisions is presented. In particular I will concentrate on the effects caused by the hot, deconfined medium and on the effort to treat them using field-theoretical, QCD-based techniques, ... More
A thermodynamical approach to dissipation range turbulenceApr 08 2003A model to explain the statistics of the velocity gradients in the dissipation range of a turbulent flow is presented. The experimentally observed non-gaussian statistics is theoretically predicted by means of a thermodynamical analogy using the maximum ... More
Statistical Hadronization and HolographyDec 14 2009Dec 17 2009In this paper we consider some issues about the statistical model of the hadronization in a holographic approach. We introduce a Rindler like horizon in the bulk and we understand the string breaking as a tunneling event under this horizon. We calculate ... More
QCD condensates in ADS/QCDSep 25 2009This paper focuses on some issues about condensates and renormalization in AdS/QCD models. In particular we consider the consistency of the AdS/QCD approach for scale dependent quantities as the chiral condensate questioned in some recent papers and the ... More
Joyce-Song wall-crossing as an asymptotic expansionDec 09 2011Jun 17 2013We conjecture that the Joyce-Song wall-crossing formula for Donaldson-Thomas invariants arises naturally from an asymptotic expansion in the field theoretic work of Gaiotto, Moore and Neitzke. This would also give a new perspective on how the formulae ... More
A Multi-agent Based Digital Preservation ModelAug 26 2014Aug 28 2014Master's Degree Thesis: Department of Physics, University of Turin Supervisor: Prof. Marco Maggiora, Department of Physics, University of Turin; email: marco.maggiora@unito.it Co-Supervisor: Prof. Walter Allasia, Innovation Department, EURIX; email: allasia@eurix.it ... More
The thermal dilepton rate at NLO at small and large invariant massOct 02 2015Oct 05 2015We report on a recent next-to-leading order perturbative determination of the dilepton rate from a hot QCD plasma for frequency and momentum of the order of the temperature and for much smaller invariant mass $M\sim gT$. We briefly review the calculation, ... More
Theoretical aspects of photon production in high energy nuclear collisionsJul 31 2014A brief overview of the calculation of photon and dilepton production rates in a deconfined quark-gluon plasma is presented. We review leading order rates as well as recent NLO determinations and non-equilibrium corrections. Furthermore, the difficulties ... More
Heavy quarkonium spectrum and width in a weakly-coupled quark-gluon plasmaAug 30 2011Sep 20 2011We report a recent calculation of the heavy quarkonium energy levels and decay widths in a quark- gluon plasma whose temperature is much smaller than the inverse radius of the bound state, based on a Non-Relativistic Effective Field theory framework for ... More
The Polyakov loop correlator at NNLO and singlet and octet correlatorsOct 19 2010We present the complete next-to-next-to-leading-order calculation of the correlation function of two Polyakov loops for temperatures smaller than the inverse distance between the loops and larger than the Coulomb potential. We discuss the relationship ... More
Effective Field Theories of QCD for Heavy Quarkonia at Finite TemperatureJan 13 2012Quarkonium suppression is one of the most investigated probes of the medium produced in heavy-ion collisions. In this thesis we extend the well-established and successful zero temperature framework of Non-Relativistic (NR) Effective Field Theories (EFTs) ... More
Simple linear compactifications of odd orthogonal groupsMar 10 2011Nov 19 2012We classify the simple linear compactifications of SO(2r+1), namely those compactifications with a unique closed orbit which are obtained by taking the closure of the SO(2r+1)xSO(2r+1)-orbit of the identity in a projective space P(End(V)), where V is ... More
The relationship between gas content and star formation rate in spiral galaxies. Comparing the local field with the Virgo clusterAug 01 2008Oct 02 2008Despite many studies of the star formation in spiral galaxies, a complete and coherent understanding of the physical processes that regulate the birth of stars has not yet been achieved, nor a unanimous consent was reached, despite the many attempts, ... More
Dual virtual element method for discrete fractures networksOct 10 2016Discrete fracture networks is a key ingredient in the simulation of physical processes which involve fluid flow in the underground, when the surrounding rock matrix is considered impervious. In this paper we present two different models to compute the ... More
Hyper non-Gaussianities in inflation with strongly non-geodesic motionFeb 08 2019Several recent proposals to embed inflation into high-energy physics rely on inflationary dynamics characterized by a strongly non-geodesic motion in negatively curved field space. This naturally leads to a transient instability of perturbations on sub-Hubble ... More
DepecheMood: a Lexicon for Emotion Analysis from Crowd-Annotated NewsMay 07 2014While many lexica annotated with words polarity are available for sentiment analysis, very few tackle the harder task of emotion analysis and are usually quite limited in coverage. In this paper, we present a novel approach for extracting - in a totally ... More
General smile asymptotics with bounded maturityNov 06 2014Jul 07 2016We provide explicit conditions on the distribution of risk-neutral log-returns which yield sharp asymptotic estimates on the implied volatility smile. We allow for a variety of asymptotic regimes, including both small maturity (with arbitrary strike) ... More
Parton energy loss and momentum broadening at NLO in high temperature QCD plasmasFeb 12 2015We present an overview of a perturbative-kinetic approach to jet propagation, energy loss, and momentum broadening in a high temperature quark-gluon plasma. The leading-order kinetic equations describe the interactions between energetic jet-particles ... More
The asymptotic smile of a multiscaling stochastic volatility modelJan 14 2015Oct 05 2016We consider a stochastic volatility model which captures relevant stylized facts of financial series, including the multi-scaling of moments. The volatility evolves according to a generalized Ornstein-Uhlenbeck processes with super-linear mean reversion. ... More
Symmetry breaking for Schrödinger-Poisson-Slater energyJan 21 2016We study the asymptotic behavior of ground state energy for Schr\"odinger-Poisson-Slater energy functional. We show that ground state energy restricted to radially symmetric functions is above the ground state energy when the number of particles is sufficiently ... More
On the theory of quantum quenches in near-critical systemsAug 26 2016Sep 21 2016The theory of quantum quenches in near-critical one-dimensional systems formulated in [J. Phys. A 47 (2014) 402001] yields analytic predictions for the dynamics, unveils a qualitative difference between non-interacting and interacting systems, with undamped ... More
Frobenius type and CV-structures for Donaldson-Thomas theory and a convergence propertyDec 03 2015We rephrase some well-known results in Donaldson-Thomas theory in terms of (formal families of) Frobenius type and CV-structures on a vector bundle in the sense of Hertling. We study these structures in an abstract setting, and prove a convergence result ... More
Extracting Information from Multiplex NetworksFeb 28 2016May 16 2016Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering ... More
Non-stationary Magnetic Microstructures in Stellar Thin Accretion DiscsSep 24 2012Feb 27 2013We examine the morphology of magnetic structures in thin plasma accretion discs, generalizing a stationary ideal MHD model to the time-dependent visco-resistive case. Our analysis deals with small scale perturbations to a central dipole-like magnetic ... More
Sequential visibility-graph motifsDec 01 2015May 02 2016Visibility algorithms transform time series into graphs and encode dynamical information in their topology, paving the way for graph-theoretical time series analysis as well as building a bridge between nonlinear dynamics and network science. In this ... More
Efficient functional ANOVA through wavelet-domain Markov grovesFeb 12 2016Feb 21 2016We introduce a wavelet-domain functional analysis of variance (fANOVA) method based on a Bayesian hierarchical model. The factor effects are modeled through a spike-and-slab mixture at each location-scale combination along with a normal-inverse-Gamma ... More
Critical Exponents of the Random Field Hierarchical ModelSep 28 2013We have studied the one dimensional Dyson hierarchical model in presence of a random field. This is a long range model where the interactions scale with the distance with a power law-like form J(r) ~ r^{-\rho} and we can explore mean field and non-mean ... More
Normality and smoothness of simple linear group compactificationsMar 07 2012Nov 19 2012If G is a complex semisimple algebraic group, we characterize the normality and the smoothness of its simple linear compactifications, namely those equivariant GxG-compactifications which possess a unique closed orbit and which arise in a projective space ... More
Orbits of strongly solvable spherical subgroups on the flag varietyNov 21 2014Apr 07 2016Let G be a connected reductive complex algebraic group and B a Borel subgroup of G. We consider a subgroup H of B acting with finitely many orbits on the flag variety G/B, and we classify the H-orbits in G/B in terms of suitable combinatorial invariants. ... More
Nonlinear Schrödinger equations with strongly singular potentialsMar 19 2009In this paper we look for standing waves for nonlinear Schr\"odinger equations $$ i\frac{\partial \psi}{\partial t}+\Delta \psi - g(|y|) \psi -W^{\prime}(| \psi |)\frac{\psi}{| \psi |}=0 $$ with cylindrically symmetric potentials $g$ vanishing at infinity ... More
Stability and instability results in a model of Fermi accelerationMar 07 2008We consider the static wall approximation to the dynamics of a particle bouncing on a periodically oscillating infinitely heavy plate while subject to a potential force. We assume the case of a potential given by a power of the particle's height and sinusoidal ... More
Orbits of strongly solvable spherical subgroups on the flag varietyNov 21 2014Aug 02 2017Let G be a connected reductive complex algebraic group and B a Borel subgroup of G. We consider a subgroup H of B acting with finitely many orbits on the flag variety G/B, and we classify the H-orbits in G/B in terms of suitable combinatorial invariants. ... More
Braid group actions on coideal subalgebras of quantized enveloping algebrasFeb 21 2011We construct braid group actions on coideal subalgebras of quantized enveloping algebras which appear in the theory of quantum symmetric pairs. In particular, we construct an action of the semidirect product of Z^n and the classical braid group in n strands ... More
Sequential motif profile of natural visibility graphsMay 09 2016The concept of sequential visibility graph motifs -subgraphs appearing with characteristic frequencies in the visibility graphs associated to time series- has been advanced recently along with a theoretical framework to compute analytically the motif ... More
Relative K-stability of extremal metricsDec 21 2009We show that if a polarised manifold admits an extremal metric then it is K-polystable relative to a maximal torus of automorphisms.
Local logarithmic correlators as limits of Coulomb gas integralsNov 08 2013We will describe how logarithmic singularities arise as limits of Coulomb Gas integrals. Our approach will combine analytic properties of the time-like Liouville structure constants, together with the recursive formula of the Virasoro conformal blocks. ... More
Torus equivariant K-stabilityFeb 10 2016We prove (using algebro-geometric methods) two results that allow to test the positivity of the Donaldson-Futaki weights of arbitrary polarised varieties via test-configurations which are equivariant with respect to a maximal torus in the automorphism ... More
Equilibrium and nonequilibrium entanglement properties of 2D and 3D Fermi gasesJan 16 2013Mar 01 2013We investigate the entanglement properties of the equilibrium and nonequilibrium quantum dynamics of 2D and 3D Fermi gases, by computing entanglement entropies of extended space regions, which generally show multiplicative logarithmic corrections to the ... More
Il fisico del neutrinoOct 29 2013Nov 11 2014In memory of the famous physicist Bruno Pontecorvo, whereof is just occurred the centenary anniversary of the birth and the twentieth anniversary of the death, this paper traces the scientific and human adventure of the italian scientist, from the pioneering ... More
Backtesting Lambda Value at RiskFeb 24 2016Jun 12 2016A new risk measure, the lambda value at risk (Lambda VaR), has been recently proposed from a theoretical point of view as a generalization of the value at risk (VaR). The Lambda VaR appears attractive for its potential ability to solve several problems ... More
Phase separation and interface structure in two dimensions from field theoryJun 21 2012Oct 30 2012We study phase separation in two dimensions in the scaling limit below criticality. The general form of the magnetization profile as the volume goes to infinity is determined exactly within the field theoretical framework which explicitly takes into account ... More
Potts q-color field theory and scaling random cluster modelApr 21 2011Jul 01 2011We study structural properties of the q-color Potts field theory which, for real values of q, describes the scaling limit of the random cluster model. We show that the number of independent n-point Potts spin correlators coincides with that of independent ... More
On three-point connectivity in two-dimensional percolationSep 07 2010We argue the exact universal result for the three-point connectivity of critical percolation in two dimensions. Predictions for Potts clusters and for the scaling limit below p_c are also given.
Regular functions on spherical nilpotent orbits in complex symmetric pairs: classical Hermitian casesDec 05 2016Given a classical semisimple complex algebraic group G and a symmetric pair (G,K) of Hermitian type, we study the closures of the spherical nilpotent K-orbits in the isotropy representation of K. We show that all such orbit closures are normal and describe ... More
The Bruhat order on Hermitian symmetric varieties and on abelian nilradicalsAug 18 2017Jul 12 2018Let $G$ be a simple algebraic group and $P$ a parabolic subgroup of $G$ with abelian unipotent radical $P^u$, and let $B$ be a Borel subgroup of $G$ contained in P. Let $\mathfrak{p}^u$ be the Lie algebra of $P^u$ and let $L$ be a Levi factor of $P$, ... More
Spectral triples on the Jiang-Su algebraSep 24 2017Feb 01 2018We construct spectral triples on a class of particular inductive limits of matrix-valued function algebras. In the special case of the Jiang-Su algebra we employ a particular $AF$-embedding.
Statistical properties of mostly contracting fast-slow partially hyperbolic systemsAug 23 2014Oct 15 2015We consider a class of $\mathcal C^{4}$ partially hyperbolic systems on $\mathbb T^2$ described by maps $F_\varepsilon(x,\theta)=(f(x,\theta),\theta+\varepsilon\omega(x,\theta))$ where $f(\cdot,\theta)$ are expanding maps of the circle. For sufficiently ... More
Exact correlations in the Lieb-Liniger model and detailed balance out-of-equilibriumNov 01 2016Nov 07 2016We study the density-density correlation function of the 1D Lieb-Liniger model and obtain an exact expression for the small momentum limit of the static correlator in the thermodynamic limit. We achieve this by summing exactly over the relevant form factors ... More
Low Mass Thermal Dilepton Production at NLO in a Weakly Coupled Quark-Gluon PlasmaOct 15 2014Dec 03 2014We present a computation, within weakly-coupled thermal QCD, of the production rate of low invariant mass ($M^2 \sim g^2 T^2$) dileptons, at next-to-leading order (NLO) in the coupling (which is $O(g^3 e^2 T^2)$). This involves extending the NLO calculation ... More
The complete census of optically selected AGNs in the Coma Supercluster: the dependence of AGN activity on the local environmentJul 19 2011Sep 14 2011To investigate the dependence of the occurrence of active galactic nuclei (AGNs) on local galaxy density, we study the nuclear properties of ~5000 galaxies in the Coma Supercluster whose density spans 2 orders of magnitude from the sparse filaments to ... More
PCR-based isolation of multigene families: Lessons from the avian MHC class IIBAug 01 2013The amount of sequence data available today highly facilitates the access to genes from many gene families. Universal primers amplifying the desired genes over a range of species are readily obtained by aligning conserved gene regions, and laborious gene ... More
Dynamics of some piecewise smooth Fermi-Ulam ModelsDec 11 2011We find a normal form which describes the high energy dynamics of a class of piecewise smooth Fermi-Ulam ping pong models; depending on the value of a single real parameter, the dynamics can be either hyperbolic or elliptic. In the first case we prove ... More
Potts models on hierarchical lattices and Renormalization Group dynamicsAug 04 2007Aug 03 2008We prove that the generator of the renormalization group of Potts models on hierarchical lattices can be represented by a rational map acting on a finite-dimensional product of complex projective spaces. In this framework we can also consider models with ... More
Fast-slow partially hyperbolic systems: beyond averaging. Part I (Limit Theorems)Aug 23 2014Sep 11 2014We prove several limit theorems for a simple class of partially hyperbolic fast-slow systems. We start with some well know results on averaging, then we give a substantial refinement of known large (and moderate) deviation results and conclude with a ... More
The martingale approach after Varadhan and DolgopyatFeb 01 2014Sep 12 2014We present, in the simplest possible form, the so called martingale problem strategy to establish limit theorems. The presentation is specially adapted to problems arising in partially hyperbolic dynamical systems. We will discuss a simple partially hyperbolic ... More
TBA type equations and tropical curvesJun 17 2013We revisit the wall-crossing behaviour of solutions to the Thermodynamic Bethe Ansatz type equations arising in a class of three-dimensional field theories, expressed as sums of "instanton corrections". We explain how to attach to an instanton correction ... More
On the interplay between hypergeometric series, Fourier-Legendre expansions and Euler sumsJun 21 2018In this work we continue the investigation about the interplay between hypergeometric functions and Fourier-Legendre ($\textrm{FL}$) series expansions. In the section "Hypergeometric series related to $\pi,\pi^2$ and the lemniscate constant", through ... More
Exact correlations in the Lieb-Liniger model and detailed balance out-of-equilibriumNov 01 2016We study the density-density correlation function of the 1D Lieb-Liniger model and obtain an exact expression for the small momentum limit of the static correlator in the thermodynamic limit. We achieve this by summing exactly over the relevant form factors ... More
A multiscale flux basis for mortar mixed discretizations of reduced Darcy-Forchheimer fracture modelsOct 30 2018In this paper, a multiscale flux basis algorithm is developed to efficiently solve a flow problem in fractured porous media. Here, we take into account a mixed-dimensional setting of the discrete fracture matrix model, where the fracture network is represented ... More
On the Hausdorff dimension of Newhouse phenomenaApr 08 2014We show that at the vicinity of a generic dissipative homoclinic unfolding of a surface diffeomorphism, the Hausdorff dimension of the set of parameters for which the diffeomorphism admits infinitely many periodic sinks is at least 1/2.
On the Existence of Martingale Measures in Jump Diffusion Market ModelsNov 26 2015In the context of jump-diffusion market models we construct examples that satisfy the weaker no-arbitrage condition of NA1 (NUPBR), but not NFLVR. We show that in these examples the only candidate for the density process of an equivalent local martingale ... More
Ring sequence decomposition of an accretion disk: the viscoresistive approachNov 04 2011We analyze a two dimensional viscoresistive magnetohydrodynamical (MHD) model for a thin accretion disk which reconciles the crystalline structure outlined in [Coppi(2005), Coppi and Rousseau(2006)] with real microscopic and macroscopic features of astrophysical ... More
An Empirical Evaluation of Portfolios Approaches for solving CSPsDec 04 2012Jan 05 2014Recent research in areas such as SAT solving and Integer Linear Programming has shown that the performances of a single arbitrarily efficient solver can be significantly outperformed by a portfolio of possibly slower on-average solvers. We report an empirical ... More
Solving XCSP problems by using GecodeDec 28 2011Gecode is one of the most efficient libraries that can be used for constraint solving. However, using it requires dealing with C++ programming details. On the other hand several formats for representing constraint networks have been proposed. Among them, ... More
Properties of dusty tori in active galactic nuclei - II. Type 2 AGNJul 14 2009(abridged) This paper is the second part of a work investigating the properties of dusty tori in AGN by means of multi-component SED fitting. It focuses on low luminosity, low redshift (z < 0.25) AGN selected among emission line galaxies as well as X-ray, ... More
Revisiting Human Action Recognition: Personalization vs. GeneralizationMay 02 2016By thoroughly revisiting the classic human action recognition paradigm, this paper aims at proposing a new approach for the design of effective action classification systems. Taking as testbed publicly available three-dimensional (MoCap) action/activity ... More
On the Abaqus FEA model of finite viscoelasticityMar 08 2013Predictions of the QLV (Quasi-Linear Viscoelastic) constitutive law are compared with those of the ABAQUS viscoelastic model for two simple motions in order to highlight, in particular, their very different dissipation rates and certain shortcomings of ... More
Ensemble renormalization group for the random field hierarchical modelJan 08 2014The Renormalization Group (RG) methods are still far from being completely understood in quenched disordered systems. In order to gain insight into the nature of the phase transition of these systems, it is common to investigate simple models. In this ... More
Least costly energy management for series hybrid electric vehiclesOct 26 2015Energy management of plug-in Hybrid Electric Vehicles (HEVs) has different challenges from non-plug-in HEVs, due to bigger batteries and grid recharging. Instead of tackling it to pursue energetic efficiency, an approach minimizing the driving cost incurred ... More
Non-equilibrium magnetic fields in ab initio spin dynamicsApr 21 2016Nov 18 2016Starting from the continuity equation for the magnetization in time-dependent spin-density functional theory, we derive an expression for the effective time-dependent magnetic fields driving the out-of-equilibrium spin dynamics in magnetic systems. We ... More
Statistical mechanics of the spherical hierarchical model with random fieldsJun 05 2014We study analytically the equilibrium properties of the spherical hierarchical model in the presence of random fields. The expression for the critical line separating a paramagnetic from a ferromagnetic phase is derived. The critical exponents characterising ... More
Measurement of CP Violation in $\mathrm{B}^{0}_{\mathrm{s}} \! \to \mathrm{J} / ψ\,φ$ decays with the CMS detectorNov 13 2014Jan 08 2015The CP-violating weak phase $\phi_\mathrm{s}$ and the decay width difference $\Delta\Gamma_{\mathrm{s}}$ of $\mathrm{B}^{0}_{\mathrm{s}}$ mesons are measured by the CMS experiment at the LHC using a data sample of $\mathrm{B}^{0}_{\mathrm{s}} \! \to \mathrm{J} ... More
Second-order Hydrodynamics in Next-to-Leading-Order QCDMay 07 2018Jul 27 2018We compute the hydrodynamic relaxation times $\tau_\pi$ and $\tau_j$ for hot QCD at next-to-leading order in the coupling with kinetic theory. We show that certain dimensionless ratios of second-order to first-order transport coefficients obey bounds ... More
Exploring Image Virality in Google PlusSep 16 2013Reactions to posts in an online social network show different dynamics depending on several textual features of the corresponding content. Do similar dynamics exist when images are posted? Exploiting a novel dataset of posts, gathered from the most popular ... More
An Enhanced Features Extractor for a Portfolio of Constraint SolversAug 01 2013Apr 02 2014Recent research has shown that a single arbitrarily efficient solver can be significantly outperformed by a portfolio of possibly slower on-average solvers. The solver selection is usually done by means of (un)supervised learning techniques which exploit ... More
Predicting epidemic evolution on contact networks from partial observationsAug 23 2016The massive employment of computational models in network epidemiology calls for the development of improved inference methods for epidemic forecast. For simple compartment models, such as the Susceptible-Infected-Recovered model, Belief Propagation was ... More
Column-Oriented Datalog Materialization for Large Knowledge Graphs (Extended Technical Report)Nov 28 2015Feb 11 2016The evaluation of Datalog rules over large Knowledge Graphs (KGs) is essential for many applications. In this paper, we present a new method of materializing Datalog inferences, which combines a column-based memory layout with novel optimization methods ... More
Ground states for semi-relativistic Schrödinger-Poisson-Slater energiesMar 14 2011Apr 08 2014We prove the existence of ground states for the semi-relativistic Schr\"odinger-Poisson-Slater energy $$I^{\alpha,\beta}(\rho)=\inf_{\substack{u\in H^\frac 12(\R^3) \int_{\R^3}|u|^2 dx=\rho}} \frac{1}{2}\|u\|^2_{H^\frac 12(\R^3)} +\alpha\int\int_{\R^{3}\times\R^{3}} ... More
Nonperturbative Instability of AdS_5 x S^5/Z_kSep 26 2007Oct 26 2007We study the AdS/CFT correspondence with boundary conditions AdS_5 x S^5/Z_k, where the Z_k acts freely but breaks all supersymmetry. While there are closed string tachyons at small 't Hooft coupling, there are no tachyons at large coupling. Nevertheless, ... More
Regular functions on spherical nilpotent orbits in complex symmetric pairs: classical non-Hermitian casesFeb 23 2016Given a classical semisimple complex algebraic group G and a symmetric pair (G, K) of non-Hermitian type, we study the closures of the spherical nilpotent K-orbits in the isotropy representation of K. For all such orbit closures, we study the normality ... More
Projective normality of model varieties and related resultsApr 23 2013Dec 31 2015We prove that the multiplication of sections of globally generated line bundles on a model wonderful variety M of simply connected type is always surjective. This follows by a general argument which works for every wonderful variety and reduces the study ... More
Quantum correlation of light scattered by disordered mediaDec 07 2015We study theoretically how multiple scattering of light in a disordered medium can spontaneously generate quantum correlations. In particular we focus on the case where the input state is Gaussian and characterize the correlations between two arbitrary ... More
Open XXZ chain and boundary modes at zero temperatureJan 30 2019We study the open XXZ spin chain in the regime Delta>1 and for generic longitudinal magnetic fields at the two boundaries. We discuss the ground state via the Bethe ansatz and we show that, in a regime where both boundary magnetic fields are equal and ... More
Dynamical Spectral rigidity among $\mathbb Z_2$-symmetric strictly convex domains close to a circleJun 01 2016We show that any sufficiently (finitely) smooth $\mathbb Z_2$-symmetric strictly convex domain sufficiently close to a circle is dynamically spectrally rigid, i.e. all deformations among domains in the same class which preserve the length of all periodic ... More