Results for "Fabrizio Arrigoni Battaia"

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The Stacked Lyman-Alpha Emission Profile from the Circum-Galactic Medium of z~2 QuasarsApr 11 2016In the context of the FLASHLIGHT survey, we obtained deep narrow band images of 15 $z\sim2$ quasars with GMOS on Gemini-South in an effort to measure Ly$\alpha$ emission from circum- and inter-galactic gas on scales of hundreds of kpc from the central ... More
Clustering of Lyman-alpha Emitters Around Quasars at $z\sim4$Apr 11 2019The strong observed clustering of $z>3.5$ quasars indicates they are hosted by massive ($M_{\rm{halo}}\gtrsim10^{12}\,h^{-1}\,\rm{M_{\odot}}$) dark matter halos. Assuming quasars and galaxies trace the same large-scale structures, this should also manifest ... More
Deep HeII and CIV Spectroscopy of a Giant Lyman alpha Nebula: Dense Compact Gas Clumps in the Circumgalactic Medium of a z~2 QuasarApr 14 2015The recent discovery by Cantalupo et al. (2014) of the largest (~500 kpc) and luminous Ly-alpha nebula associated with the quasar UM287 (z=2.279) poses a great challenge to our current understanding of the astrophysics of the halos hosting massive z~2 ... More
A VLT/FORS2 Narrowband Imaging Search for MgII Emission Around z ~ 0.7 GalaxiesMay 14 2019We perform a Very Large Telescope FOcal Reducer and low dispersion Spectrograph 2 (VLT/FORS2) narrowband imaging search around 5 star-forming galaxies at redshift z=0.67-0.69 in the Great Observatories Origins Deep Survey South (GOODS-S) field to constrain ... More
A cosmic web filament revealed in Lyman-alpha emission around a luminous high-redshift quasarJan 17 2014Simulations of structure formation in the Universe predict that galaxies are embedded in a "cosmic web", where the majority of baryons reside as rarefied and highly ionized gas. This material has been studied for decades in absorption against background ... More
Extended and broad Lyman alpha emission around a BAL quasar at z~5Feb 09 2018In this work we report deep MUSE observations of a Broad Absorption Line (BAL) quasar at z ~ 5, revealing a Lyman alpha nebula with a maximum projected linear size of ~ 60 kpc around the quasar (down to our 2-sigma SB limit per layer of ~ 9e-19 erg/s/cm^2/arcsec^2 ... More
Inspiraling Halo Accretion Mapped in Lyman-$α$ Emission around a $z\sim3$ QuasarSep 24 2017In an effort to search for Ly$\alpha$ emission from circum- and intergalactic gas on scales of hundreds of kpc around $z\sim3$ quasars, and thus characterise the physical properties of the gas in emission, we have initiated an extensive fast-survey with ... More
Mapping the Lyman-Alpha Emission Around a z~6.6 QSO with MUSE: Extended Emission and a Companion at Close SeparationSep 18 2017We utilize the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to search for extended Lyman-Alpha emission around the z~6.6 QSO J0305-3150. After carefully subtracting the point-spread-function, we reach a nominal 5-sigma surface ... More
Discovery of a dual AGN at z~3.3 with 20kpc separationJan 16 2018Mar 19 2018A prediction of the current paradigm of the hierarchical assembly of galaxies is the presence of supermassive dual black holes at separations of a few kpc or less. In this context, we report the detection of a narrow-line emitter within the extended LyA ... More
Keck/Palomar Cosmic Web Imagers (KCWI/PCWI) Reveal an Enormous Ly$α$ Nebula in an Extremely Overdense QSO Pair Field at $z=2.45$Mar 28 2018Enormous Ly$\alpha$ nebulae (ELANe) represent the extrema of Ly$\alpha$ nebulosities. They have detected extents of $>200$ kpc in Ly$\alpha$ and Ly$\alpha$ luminosities $>10^{44}$ erg s$^{-1}$. The ELAN population is an ideal laboratory to study the interactions ... More
Spatially Resolved Metal Gas CloudsMay 18 2018Jul 30 2018We now have mounting evidences that the circumgalactic medium (CGM) of galaxies is polluted with metals processed through stars. The fate of these metals is however still an open question and several findings indicate that they remain poorly mixed. A ... More
MUSE unravels the ionisation and origin of metal enriched absorbers in the gas halo of a z = 2.92 radio galaxyApr 10 2019We have used the Multi-Unit Spectroscopic Explorer (MUSE) to study the circumgalactic medium (CGM) of a z = 2.92 radio galaxy, MRC 0943-242 by parametrising its emitting and absorbing gas. In both Ly$\alpha$ $\lambda$1216 and He II $\lambda$1640 lines, ... More
Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant UniverseMay 14 2015All galaxies once passed through a hyperluminous quasar phase powered by accretion onto a supermassive black hole. But because these episodes are brief, quasars are rare objects typically separated by cosmological distances. In a survey for Lyman-alpha ... More
A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$α$ BlobsJul 10 2014We conduct a deep narrow-band imaging survey of 13 Ly$\alpha$ blobs (LABs) located in the SSA22 proto-cluster at z~3.1 in the CIV and HeII emission lines in an effort to constrain the physical process powering the Ly$\alpha$ emission in LABs. Our observations ... More
Mapping Galaxy Clusters in the Distant UniverseMar 14 2019We present the science case for mapping several thousand galaxy (proto)clusters at z=1-10 with a large aperture single dish sub-mm facility, producing a high-redshift counterpart to local large surveys of rich clusters like the well-studied Abell catalogue. ... More
Discovery of a Lya emitting dark-cloud within z ~ 2.8 SMMJ02399-0136 systemMar 07 2019We present Keck/KCWI integral field spectrograph observations of the complex system surrounding SMM J02399$-$0136 (a lensed $z=2.8$ sub-mm galaxy), including an associated Ly$\rm \alpha$ nebula, a dust-obscured, broad-absorption-line quasar, and neighboring ... More
Robust Motion Segmentation from Pairwise MatchesMay 22 2019In this paper we address a classification problem that has not been considered before, namely motion segmentation given pairwise matches only. Our contribution to this unexplored task is a novel formulation of motion segmentation as a two-step process. ... More
Fast Strassen-based $A^t A$ Parallel MultiplicationFeb 06 2019Matrix multiplication $A^t A$ appears as intermediate operation during the solution of a wide set of problems. In this paper, we propose a new cache-oblivious algorithm for the $A^t A$ multiplication. Our algorithm, A$\scriptstyle \mathsf{T}$A, calls ... More
Dispersive spectrum and orbital order of spinless p-band fermions in an optical latticeFeb 02 2009Jun 22 2009We study single-particle properties of a spinless p-band correlated fermionic gas in an optical lattice by means of a variational cluster approach (VCA). The single-particle spectral function is almost flat at half-filling and develops a strongly dispersive ... More
On an exact criterion for choosing the hopping operator in the four-slave-boson approachAug 16 1995We consider the $N$-component generalization of the four-slave-boson approach to the Hubbard model, where $1/N$ acts as the small parameter that controls the fluctuations about the saddle point, and address the problem of the appropriate choice of the ... More
Stripped gas as fuel for newly formed HII regions in the encounter between VCC1249 and M49: a unified picture from NGVS and GUViCSMay 14 2012May 15 2012Context: We study the peculiar interacting galaxy system of VCC1249/M49 located in the core of the Virgo B subcluster. Owing to a recent interaction between the dwarf galaxy VCC1249 and the halo gas of the gE M49, neutral hydrogen has been displaced from ... More
Non-equilibrium variational cluster perturbation theory: quench dynamics of the quantum Ising modelMay 02 2016We introduce a variational implementation of cluster perturbation theory (CPT) to address the dynamics of spin systems driven out of equilibrium. We benchmark the method with the quantum Ising model subject to a sudden quench of the transverse magnetic ... More
Comparing the performance of LDA and GGA functionals in predicting the lattice thermal conductivity of semiconductor materials: the case of AlAsNov 15 2018In this contribution we assess the performance of two different exchange-correlation functionals in the first-principle prediction of the lattice thermal conductivity of bulk semiconductors, namely the local density approximation (LDA) and the Perdew-Burke-Ernzerhof ... More
Phase-fluctuation induced reduction of the kinetic energy at the superconducting transitionJul 17 2002Jul 15 2003Recent reflectivity measurements provide evidence for a "violation" of the in-plane optical integral in the underdoped high-T_c compound Bi_2Sr_2CaCu_2O_{8+\delta} up to frequencies much higher than expected by standard BCS theory. The sum rule violation ... More
Limit order placement as an utility maximization problem and the origin of power law distribution of limit order pricesDec 01 2006I consider the problem of the optimal limit order price of a financial asset in the framework of the maximization of the utility function of the investor. The analytical solution of the problem gives insight on the origin of the recently empirically observed ... More
Measurements of top quark properties at the Tevatron colliderMay 26 2011The discovery of the top quark in 1995 opened a whole new sector of investigation of the Standard Model; today top quark physics remains a key priority of the Tevatron program. Some of the measurements of top quark properties, for example its mass, will ... More
Teaching Waves with Google EarthDec 24 2011Google Earth is a huge source of interesting illustrations of various natural phenomena. It can represent a valuable tool for science education, not only for teaching geography and geology, but also physics. Here we suggest that Google Earth can be used ... More
Full electrical control of Charge and Spin conductance through Interferometry of Edge States in Topological InsulatorsNov 19 2010May 13 2011We investigate electron interferometry of edge states in Topological Insulators. We show that, when inter-boundary coupling is induced at two quantum point contacts of a four terminal setup, both Fabry-P\'erot-like and Aharonov-Bohm-like loop processes ... More
Random walks over a super-percolating two dimensional latticeOct 02 2015Two-dimensional networks of ordered quantum dots beyond the percolation threshold are studied, as typical example of conducting nanostructures with quenched random disorder. Theory predicts anomalous diffusion with stretched-exponential relaxation at ... More
Energy Spectrum of Anyons in a Magnetic FieldJul 29 1992For the many-anyon system in external magnetic field, we derive the energy spectrum as an exact solution of the quantum eigenvalue problem with particular topological constraints. Our results agree with the numerical spectra recently obtained for the ... More
Superconductivity from doping a spin liquid insulator: a simple one-dimensional exampleMar 15 1996Mar 28 1996We study the phase diagram of a one-dimensional Hubbard model where, in addition to the standard nearest neighbor hopping $t$, we also include a next-to-nearest neighbor hopping $t'$. For strong enough on-site repulsion, this model has a transition at ... More
Process-aware web programming with JolieOct 14 2014Apr 21 2016We extend the Jolie programming language to capture the native modelling of process-aware web information systems, i.e., web information systems based upon the execution of business processes. Our main contribution is to offer a unifying approach for ... More
High Energy Large Area Surveys: from BeppoSAX to Chandra and XMM-NewtonSep 12 2003Hard X-ray observations are the most efficient way to discriminate accretion-powered sources from star-light. Furthermore, hard X-rays are less affected than other bands by obscuration. For these reasons the advent of imaging instruments above 2 keV, ... More
Counting algebraic integers of fixed degree and bounded heightMay 02 2013Nov 12 2013Let $k$ be a number field. For $\mathcal{H}\rightarrow \infty$, we give an asymptotic formula for the number of algebraic integers of absolute Weil height bounded by $\mathcal{H}$ and fixed degree over $k$.
Complex angular momenta approach for scattering problems in the presence of both monopoles and short range potentialsOct 13 2016It is analyzed the quantum mechanical scattering off a topological defect (such as a Dirac monopole) as well as a Yukawa-like potential(s) representing the typical effects of strong interactions. This system, due to the presence of a short-range potential, ... More
Canonical symplectic structures and deformations of algebraic surfacesAug 04 2006May 15 2007We show that a minimal surface of general type has a canonical symplectic structure (unique up to symplectomorphism) which is invariant for smooth deformation. We show that the symplectomorphism type is also invariant for deformations which allow certain ... More
Involutory reflection groups and their modelsMay 22 2009A finite subgroup of $GL(n,\mathbb C)$ is involutory if the sum of the dimensions of its irreducible complex representations is given by the number of absolute involutions in the group. A uniform combinatorial model is constructed for all non-exceptional ... More
CM relations in fibered powers of elliptic familiesNov 07 2016Jul 04 2018Let $E_\lambda$ be the Legendre family of elliptic curves. Given $n$ linearly independent points $P_1,\dots , P_n \in E_\lambda\left(\overline{\mathbb{Q}(\lambda)}\right)$ we prove that there are at most finitely many complex numbers $\lambda_0$ such ... More
Rational curves on fibered varietiesSep 25 2018Mar 13 2019Let $X$ be a projective variety with log terminal singularities and vanishing augmented irregularity. In this paper we prove that if $X$ admits a relatively minimal genus one fibration then it does contain a subvariety of codimension one covered by rational ... More
Fibred K"ahler and quasi-projective GroupsJul 04 2003We formulate a new theorem giving several necessary and sufficient conditions in order that a surjection of the fundamental group $\pi_1(X)$ of a compact K\"ahler manifold onto the fundamental group $\Pi_g$ of a compact Riemann surface of genus $g \geq ... More
Level algebras of type 2Nov 10 2004Mar 29 2005In this paper we study standard graded artinian level algebras, in particular those whose socle-vector has type 2. Our main results are: the characterization of the level $h$-vectors of the form $(1,r,...,r,2)$ for $r\leq 4$; the characterization of the ... More
Extending the idea of compressed algebra to arbitrary socle-vectors, II: cases of non-existenceNov 24 2004This paper is the continuation of the previous work on generalized compressed algebras (GCA's). First we exhibit a new class of socle-vectors $s$ which admit a GCA (whose $h$-vector is lower than the upper-bound $H$ of Theorem A of the previous paper). ... More
Stanley's theorem on codimension 3 Gorenstein $h$-vectorsNov 10 2004Mar 04 2005In this note we supply an elementary proof of the following well-known theorem of R. Stanley: the $h$-vectors of Gorenstein algebras of codimension 3 are SI-sequences, i.e. are symmetric and the first difference of their first half is an $O$-sequence. ... More
Surface classification and local and global fundamental groups, IFeb 07 2006Apr 14 2006Given a smooth complex surface S, and a compact connected global normal crossings divisor $D = \cup_i D_i$, we consider the local fundamental group, i.e., the fundamental group Gamma of T-D, where T is a good tubular neighbourhood of D. One has a surjection ... More
Deformations in the large of some complex manifolds, IJul 04 2003Main topic of the paper is the determination, for a compact complex manifold $M$, of the class of manifolds $X$ which are deformation equivalent to it. If $M$ is a complex torus, then also $X$ is so. After describing the structure of principal holomorphic ... More
Moduli spaces of surfaces and real structuresMar 12 2001Apr 29 2004We give infinite series of groups Gamma and of compact complex surfaces of general type S with fundamental group Gamma such that 1) Any surface S' with the same Euler number as S, and fundamental group Gamma, is diffeomorphic to S. 2) The moduli space ... More
Monodromy and normal formsJul 02 2015We discuss the history of the monodromy theorem, starting from Weierstra\ss, and the concept of monodromy group. From this viewpoint we compare then the Weierstra\ss , the Legendre and other normal forms for elliptic curves, explaining their geometric ... More
Odd values of the Klein j-function and the cubic partition functionSep 22 2014Jan 30 2015In this note, using entirely algebraic or elementary methods, we determine a new asymptotic lower bound for the number of odd values of one of the most important modular functions in number theory, the Klein $j$-function. Namely, we show that the number ... More
Zeilberger's KOH theorem and the strict unimodality of q-binomial coefficientsNov 18 2013Apr 01 2014A recent nice result due to I. Pak and G. Panova is the strict unimodality of the $q$-binomial coefficients $\binom{a+b}{b}_q$ (see \cite{PP} and also \cite{PP2} for a slightly revised version of their theorem). Since their proof used representation theory ... More
Semi-Classical Quantization of the Many-Anyon SystemJul 29 1992We discuss the problem of N anyons in harmonic well, and derive the semi-classical spectrum as an exactly solvable limit of the many-anyon Hamiltonian. The relevance of our result to the solution of the anyon-gas model is discussed.
Superfluidity and vortices: A Ginzburg-Landau modelMay 30 2008The paper deals with the study of superfluidity by a Ginzburg-Landau model that investigates the material by a second order phase transition, in which any particle has simultaneouly a normal and superfluid motion. This pattern is able to describe the ... More
The Out-of-Equilibrium Time-Dependent Gutzwiller ApproximationApr 10 2012We review the recently proposed extension of the Gutzwiller approximation, M. Schiro' and M. Fabrizio, Phys. Rev. Lett. 105, 076401 (2010), designed to describe the out-of-equilibrium time-evolution of a Gutzwiller-type variational wave function for correlated ... More
On the hadronic cascade scenario for extreme BL LacsDec 16 2013The peculiar high-energy emission spectrum of the so-called extreme BL Lacs (EHBL) challenges the standard emission models of blazars. Among the possible solutions, the so-called hadronic cascade scenario assumes that the observed high-energy radiation ... More
Kallen-Lehman approach to 3D Ising modelJan 08 2007A "Kallen-Lehman" approach to Ising model, inspired by quantum field theory a la Regge, is proposed. The analogy with the Kallen-Lehman representation leads to a formula for the free-energy of the 3D model with few free parameters which could be matched ... More
A note on Gribov copies in 3D Chern-Simons theoryFeb 26 2008Mar 06 2008Using powerful tools of harmonic maps and integrable systems, all the Gribov copies in the Coulomb gauge in 3D Chern-Simons theory are constructed. Some issues about the Gribov and the modular re- gions are shortly discussed. The Gribov copies of the ... More
The quark-composites approach to QCD: The nucleon-pion interactionMay 11 1999Oct 14 1999We derive the pion-nucleon interaction in the framework of a new perturbative approach to QCD, based on the use of quark composites as fundamental variables. The composites with the quantum numbers of the nucleons are assumed as new integration variables ... More
Top physics at the Tevatron ColliderOct 19 2007The top quark has been discovered in 1995 at the CDF and DO experiments located in the Tevatron ring at the Fermilab laboratory. After more than a decade the Tevatron collider, with its center-of-mass energy collisions of 1.96 TeV, is still the only machine ... More
Rational curves on regular elliptic fiber spacesSep 25 2018In this paper we are looking for necessary and sufficient conditions for an elliptic fibration to have rational curves. We show that a projective variety with log terminal singularities and vanishing augmented irregularity that admits a numerically relatively ... More
On the canonical map of some surfaces isogenous to a productApr 04 2017We give new contributions to the existence problem of canonical surfaces of high degree. We construct several families (indeed, connected components of the moduli space) of surfaces $S$ of general type with $p_g=5,6$ whose canonical map has image $\Sigma$ ... More
Misiurewicz parameters and dynamical stability of polynomial-like maps of large topological degreeDec 08 2016Given a family of polynomial-like maps of large topological degree, we relate the presence of Misiurewicz parameters to a growth condition of the postcritical volume. This allows us to generalize to this setting the theory of stability and bifurcation ... More
Q.E.D. for algebraic varietiesSep 30 2005We introduce a new equivalence relation, denoted by $A.Q.E.D.$ (= Algebraic-Quasi-\'Etale- Deformation) for complete algebraic varieties with canonical singularities: it is generated by birational equivalence, by flat algebraic deformations, and by quasi-\'etale ... More
Caustics of plane curves, their birationality and matrix projectionsApr 13 2013Jun 24 2013After recalling the notion of caustics of plane curves and basic equations, we first show the birationality of the caustic map for a general source point S in the plane. Then we prove more generally a theorem for curves D in the projective space of 3x3 ... More
Arithmetic for Rooted TreesOct 19 2015Feb 01 2016We propose a new arithmetic for non-empty rooted unordered trees simply called trees. After discussing tree representation and enumeration, we define the operations of tree addition, multiplication and stretch, prove their properties, and show that all ... More
Noise and current correlations in tunnel junctions of Quantum Spin Hall edge statesSep 02 2015Oct 19 2015The edge channels of two-dimensional topological systems are protected from elastic reflection and are noiseless at low temperature. Yet, noise and cross-correlations can be induced when electron waves partly transmit to the opposite edge via tunneling ... More
Signature of interaction in dc transport of ac gated Quantum Spin Hall edge statesSep 27 2011In the presence of a scattering potential, electron transport in a quantum wire is known to be dramatically modified by backward scattering and unaffected by forward scattering processes. We show that the scenario is quite different in Quantum Spin Hall ... More
Gutzwiller description of non-magnetic Mott insulators: a dimer lattice modelApr 11 2007We introduce a novel extension of the Gutzwiller variational wavefunction able to deal with insulators that escape any mean-field like description, as for instance non-magnetic insulators. As an application, we study the Mott transition from a paramagnetic ... More
Multiwavelength perspective of AGN evolutionFeb 18 2010Discovering and studying obscured AGN at z>1-3 is important not only to complete the AGN census, but also because they can pinpoint galaxies where nuclear accretion and star-formation are coeval, and mark the onset of AGN feedback. We present the latest ... More
Cayley forms and self dual varietiesDec 28 2011Jan 05 2012Generalized Chow forms were introduced by Cayley for the case of 3-space, their zero set on the Grassmannian G(1,3) is either the set Z of lines touching a given space curve (the case of a `honest' Cayley form), or the set of lines tangent to a surface. ... More
The detection of low-energy Quantum Gravity fluctuations with entangled statesOct 13 2009We propose a thought experiment to detect low-energy Quantum Gravity phenomena using Quantum Optical Information Technologies. Gravitational field perturbations, such as gravitational waves and quantum gravity fluctuations, decohere the entangled photon ... More
Topology of configuration space of mean-field phi^4 model by Morse theoryNov 12 2016In this paper we present the study of the topology of the equipotential hypersurfaces of configuration space of the mean-field phi^4 model. Our purpose is discovering, if any, the relation between the second-order Z_2-symmetry breaking phase transition ... More
CM relations in fibered powers of elliptic familiesNov 07 2016Nov 12 2016Let $E_\lambda$ be the Legendre family of elliptic curves. Given $n$ linearly independent points $P_1,\dots , P_n \in E_\lambda\left(\overline{\mathbb{Q}(\lambda)}\right)$ we prove that there are at most finitely many complex numbers $\lambda_0$ such ... More
Signed mahonians on some trees and parabolic quotientsMar 24 2011Apr 19 2012We study the distribution of the major index with sign on some parabolic quotients of the symmetric group, extending and generalizing simultaneously results Gessel-Simion and Adin-Gessel-Roichman, and on some special trees that we call rakes. We further ... More
Measurement of the top quark properties at the Tevatron and the LHCFeb 25 2014Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ... More
Top quark pair production at the TevatronNov 21 2010The top quark has been discovered in 1995 by the CDF and D0 experiments located at the two beam-crossing points at the Tevatron ppbar collider. The top quark is the most massive of the known elementary particles. At hadron-hadron colliders, top quarks ... More
Classical Higher-Order ProcessesFeb 08 2018Classical Processes (CP) is a calculus where the proof theory of classical linear logic types communicating processes with mobile channels, a la pi-calculus. Its construction builds on a recent propositions as types correspondence between session types ... More
When are There Infinitely Many Irreducible Elements in a Principal Ideal Domain?Nov 11 2004It has been a well-known fact since Euclid's time that there exist infinitely many rational primes. Two natural questions arise: In which other rings, sufficiently similar to the integers, are there infinitely many irreducible elements? Is there a unifying ... More
Algebraic Surfaces and their Moduli Spaces: Real, Differentiable and Symplectic StructuresDec 23 2008The article surveys published and not yet published results about moduli spaces of algebraic surfaces.
Parabolic implosion for endomorphisms of $\mathbb{C}^2$Jul 27 2016We give an estimate of the discontinuity of the large Julia set for a perturbation of a class of maps tangent to the identity, by means of a two-dimensional Lavaurs Theorem. We adapt to our situation a strategy due to Bedford, Smillie and Ueda in the ... More
The $h$-vector of a relatively compressed level algebraMar 24 2005Oct 31 2005The purpose of this note is to supply an upper and a lower bound (which are in general sharp) for the $h$-vector of a level algebra which is relatively compressed with respect to any arbitrary level algebra $A$. The useful concept of relatively compressed ... More
Partial derivatives of a generic subspace of a vector space of forms: quotients of level algebras of arbitrary typeFeb 22 2005Mar 17 2005Given a vector space $V$ of homogeneous polynomials of the same degree over an infinite field, consider a generic subspace $W$ of $V$. The main result of this paper is a lower-bound (in general sharp) for the dimensions of the spaces spanned in each degree ... More
CFOF: A Concentration Free Measure for Anomaly DetectionJan 14 2019We present a novel notion of outlier, called the Concentration Free Outlier Factor, or CFOF. As a main contribution, we formalize the notion of concentration of outlier scores and theoretically prove that CFOF does not concentrate in the Euclidean space ... More
Kodaira fibrations and beyond: methods for moduli theoryNov 21 2016Kodaira fibred surfaces are a remarkable example of projective classifying spaces, and there are still many intriguing open questions concerning them, especially the slope question. The topological characterization of Kodaira fibrations is emblematic ... More
Machine Learning in Automated Text CategorizationOct 26 2001The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research ... More
Higgs physics at the TevatronSep 15 2014Sep 16 2014We show the latest results from the CDF and D0 collaborations on the study of the Higgs boson, stemming from the analysis of the entire Tevatron Run\,II dataset. Combining the results of many individual analyses, most of which use the full data set available, ... More
More on 't Hooft loops in N=4 SYMJul 27 2012We study supersymmetric 't Hooft loop operators in N=4 super Yang-Mills, generalizing the well-known circular 1/2 BPS case and investigating their S-duality properties. We derive the BPS condition for a generic line operator describing pointlike monopoles ... More
From Abel's heritage: transcendental objects in algebraic geometry and their algebrizationJul 04 2003Oct 10 2003A mixture of an historical article, and of a survey of recent developments, containing also a couple of new results.
An elliptic Virasoro symmetry in 6dNov 02 2015We define an elliptic deformation of the Virasoro algebra. We argue that the $\mathbb{R}^4\times \mathbb{T}^2$ Nekrasov partition function reproduces the chiral blocks of this algebra. We support this proposal by showing that at special points in the ... More
Kickstarting Choreographic ProgrammingFeb 09 2015Feb 10 2015We present an overview of some recent efforts aimed at the development of Choreographic Programming, a programming paradigm for the production of concurrent software that is guaranteed to be correct by construction from global descriptions of communication ... More
Jets from subpc to kpc scaleDec 13 2002The Chandra discovery of bright X-ray emission from kpc-scale jets provides us unprecedented insights into the physical state of the plasma in the flow. In particular it is possible to get good constraints on the power and pressure in bright knots. For ... More
Surfaces with p_g = 0: Constructions and Moduli spaces, Burniat surfaces and deformations of automorphismsMay 31 2012The article is a slightly extended version of the talk, with the same title, which I gave at the Kinosaki Symposium on Algebraic Geometry in October 2011, and dealing with the classification of complex projective surfaces of general type with vanishing ... More
Incompressible fluid inside an astrophysical black hole?Jul 18 2007Aug 29 2007It is argued that under natural hypothesis the Fermions inside a black hole formed after the collapse of a neutron star could form a non compressible fluid (well before reaching the Planck scale) leading to some features of integer Quantum Hall Effect. ... More
Non-linear superposition law and Skyrme crystalsJun 30 2013Sep 13 2013Exact configurations of the four dimensional Skyrme model are presented. The static configurations have the profile which behaves as a kink and, consequently, the corresponding energy momentum tensor describes a domain wall. Furthermore, a class of exact ... More
Hamilton-Jacobi equation and the breaking of the WKB approximationJan 20 2005Feb 07 2005A simple method to deal with four dimensional Hamilton-Jacobi equation for null hypersurfaces is introduced. This method allows to find simple geometrical conditions which give rise to the failure of the WKB approximation on curved spacetimes. The relation ... More
Entanglement in the states of the Two-Rotor-ModelAug 19 2015Mar 01 2016The eigenfunctions of the Two-Rotors Model are superpositions of states corresponding to precessions of the rotors around two orthogonal axes. In Nuclear Physics such an entanglement has not been directly confirmed. We discuss how it might be observed ... More
Trecce, Mapping class group, fibrazioni di Lefschetz ed applicazioni al diffeomorfismo di superficie algebricheMay 14 2004Jul 25 2005Purpose of the Conference article, intended for a wider audience, is to introduce concepts and techniques used by Bronislaw Wajnryb and the author in order to show the diffeomorphism of certain elementary algebraic surfaces, called ABC surfaces, which ... More
Rational curves on fibered varietiesSep 25 2018In this paper we show that a projective variety with log terminal singularities and vanishing augmented irregularity that admits a relatively minimal elliptic fibration does contain a subvariety of codimension one covered by rational curves contracted ... More
Turbulence phenomena for viscous fluids by a phase field model. Vorticies and instabilityMay 16 2018Through Ginzburg-Landau and Navier-Stokes equations, we study turbulence phenomena for viscous incompresible and compressible fluids by a second order phase transition. For this model, the velocity is defined by the sum of classical and whirling components. ... More
Models with Phase Transition Triggered by Double-Well Potentials and Dumbbell Equipotential HypersurfacesMar 29 2019In some recent papers some theorems on sufficient conditions for the occurrence of $\mathbb{Z}_2$-symmetry breaking phase transition (SBPT) have been showed making use of geometric-topological features of the potential energy landscape. In particular ... More
Canonical surfaces of higher degreeFeb 04 2016We consider a family of surfaces of general type $S$ with $K_S$ ample, having $K^2_S = 24, p_g (S) = 6, q(S)=0$. We prove that for these surfaces the canonical system is base point free and yields an embedding $\Phi_1 : S \rightarrow \mathbb{P}^5$. This ... More
Topological methods in moduli theoryNov 12 2014Jul 02 2015One of the main themes of this long article is the study of projective varieties which are K(H,1)'s, i.e. classifying spaces BH for some discrete group H. After recalling the basic properties of such classifying spaces, an important class of such varieties ... More