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Random Combinatorial Optimization Problems: Mean Field and Finite-Dimensional ResultsFeb 01 2019This PhD thesis is organized as follows. In the first two chapters I will review some basic notions of statistical physics of disordered systems, such as random graph theory, the mean-field approximation, spin glasses and combinatorial optimization. The ... More

Average optimal cost for the Euclidean TSP in one dimensionNov 20 2018The traveling-salesman problem is one of the most studied combinatorial optimization problems, because of the simplicity in its statement and the difficulty in its solution. We study the traveling salesman problem when the positions of the cities are ... More

Selberg integrals in 1D random Euclidean optimization problemsOct 01 2018We consider a set of Euclidean optimization problems in one dimension, where the cost function associated to the couple of points $x$ and $y$ is the Euclidean distance between them to an arbitrary power $p\ge1$, and the points are chosen at random with ... More

The Random Fractional Matching ProblemFeb 08 2018We consider two formulations of the random-link fractional matching problem, a relaxed version of the more standard random-link (integer) matching problem. In one formulation, we allow each node to be linked to itself in the optimal matching configuration. ... More

Solution for a Bipartite Euclidean TSP in one dimensionFeb 05 2018The travelling salesman problem is one of the most studied combinatorial optimization problems, because of the simplicity in its statement and the difficulty in its solution. We characterize the optimal cycle for every convex and increasing cost function ... More

Quantum Monte Carlo Study of electrons in low dimensionsDec 19 1999We report on a diffusion Monte Carlo investigation of model electron systems in low dimensions, which should be relevant to the physics of systems obtainable nowadays in semiconductor heterostructures. In particular, we present results for a one dimensional ... More

On KdV characters in large c CFTsJan 29 2019Two-dimensional conformal field theories with just Virasoro symmetry are endowed with integrable structure. We review how to construct the integrable charges in a two-dimensional conformal field theory and how to relate them to the charges of quantum ... More

Beam Models for Gamma-Ray Bursts Sources: Outflow Structure, Kinematics and Emission MechanismsMar 25 2002Jul 27 2002The variety of gamma-ray burst phenomenology could be largely attributable to differences in the opening angle of an isotropic outflow or to a standard type of event viewed from different orientations. Motivated by this currently popular idea, we study ... More

Characterization of a photon counting EMCCD for space-based high contrast imaging spectroscopy of extrasolar planetsJul 02 2014Aug 11 2014We present the progress of characterization of a low-noise, photon counting Electron Multiplying Charged Coupled Device (EMCCD) operating in optical wavelengths and demonstrate possible solutions to the problems of Clock-Induced Charge (CIC) and other ... More

Smooth surjections and surjective restrictionsJul 06 2016Given a surjective mapping $f : E \to F$ between Banach spaces, we investigate the existence of a subspace $G$ of $E$, with the same density character as $F$, such that the restriction of $f$ to $G$ remains surjective. We obtain a positive answer whenever ... More

Butterflies in a Semi-Abelian ContextApr 21 2011It is known that monoidal functors between internal groupoids in the category Grp of groups constitute the bicategory of fractions of the 2-category Grpd(Grp) of internal groupoids, internal functors and internal natural transformations in Grp with respect ... More

Cosmological Aspects of Gamma-Ray Bursts: Luminosity Evolution and an Estimate of the Star Formation Rate at High RedshiftsAug 11 2001Apr 01 2002Using 220 Gamma-Ray Burst (GRB) redshifts and luminosities derived from the luminosity-variability relationship of Fenimore & Ramirez-Ruiz (2000), we show that there exists a significant correlation between the GRB luminosity and redshift. In particular, ... More

Spontaneous interlayer superfluidity in bilayer systems of cold polar moleculesNov 08 2009Dec 15 2010Quantum degenerate cold-atom gases provide a remarkable opportunity to study strongly interacting systems. Recent experimental progress in producing ultracold polar molecules with a net electric dipole moment opens up new possibilities to realize novel ... More

Peano on definition of surface areaDec 08 2014In this paper we investigate the evolution of the concept of area in Peano's works, taking into account the main role played by Grassmann's geometric-vector calculus and Peano's theory on derivative of measures. Geometric (1887) and bi-vectorial (1888) ... More

Multimodal Differential Emission Measure in the Solar CoronaMar 09 2015The Atmospheric Imaging Assembly (AIA) telescope on board the Solar Dynamics Observatory (SDO) provides coronal EUV imaging over a broader temperature sensitivity range than the previous generations of instruments (EUVI, EIT, and TRACE). Differential ... More

Reduction theory for mapping class groups and applications to moduli spacesJan 10 2008Let $S=S_{g,p}$ be a compact, orientable surface of genus $g$ with $p$ punctures and such that $d(S):=3g-3+p>0$. The mapping class group $\textup{Mod}_S$ acts properly discontinuously on the Teichm\"uller space $\mathcal T(S)$ of marked hyperbolic structures ... More

Peano on derivative of measures, strict derivative of distributive set functionsFeb 22 2010By retracing research on coexistent magnitudes (grandeurs coexistantes) by Cauchy (1841), Peano in "Applicazioni geometriche del calcolo infinitesimale" (1887) defines the "density" (strict derivative) of a "mass" (a distributive set function) with respect ... More

On the spectral set of a solvable Lie algebra of operatorsOct 30 2015Given $L$ a complex solvable finite dimensional Lie Algebra of operators acting on a Banach space $E$ and $\{ x_i\}_{1\le i\le n}$ a Jordan-H\"older basis of $ L$, we study the relation between $Sp(L,E)$ and $\Pi Sp(x_i)$.

Direct and inverse limits of normed modulesFeb 11 2019The aim of this note is to study existence and main properties of direct and inverse limits in the category of normed $L^0$-modules (in the sense of Gigli) over a metric measure space.

Algebraic Image ProcessingOct 11 2017We propose an approach to image processing related to algebraic operators acting in the space of images. In view of the interest in the applications in optics and computer science, mathematical aspects of the paper have been simplified as much as possible. ... More

On Cartan Joint SpectraJul 10 2014In this work several results regarding the Cartan version of the Taylor, the Slodkowski, the Fredholm, the split and the Fredholm split joint spectra will be studied.

Joint spectra of the tensor product representation of the direct sum of two solvable Lie algebrasAug 12 2016Given two complex Banach spaces $X_1$ and $X_2$, a tensor product $X_1\tilde{\otimes} X_2$ of $X_1$ and $X_2$ in the sense of [14], two complex solvable finite dimensional Lie algebras $L_1$ and $L_2$, and two representations $\rho_i\colon L_i\to {\rm ... More

Joint spectra and nilpotent Lie algebras of linear transformationsFeb 16 2016Given a complex nilpotent finite dimensional Lie algebra of linear transformations $L$, in a complex finite dimensional vector space $E$, we study the joint spectra $Sp(L,E)$, $\sigma_{\delta,k}(L,E)$ and $\sigma_{\pi,k}(L,E)$. We compute them and we ... More

On the joint spectra of the two dimensional Lie algebra of operators in Hilbert spacesMar 09 2016We consider the complex solvable non-commutative two dimensional Lie algebra $L$, $L=<y>\oplus <x>$, with Lie bracket $[x,y]=y$, as linear bounded operators acting on a complex Hilbert space $H$. Under the assumption $R(y)$ closed, we reduce the computation ... More

$L^p$-parabolic regularity and non-degenerate Ornstein-Uhlenbeck type operatorsMay 20 2014We prove $L^p$-parabolic a-priori estimates for $\partial_t u + \sum_{i,j=1}^d c_{ij}(t)\partial_{x_i x_j}^2 u = f $ on $R^{d+1}$ when the coefficients $c_{ij}$ are locally bounded functions on $R$. We slightly generalize the usual parabolicity assumption ... More

Interlayer excitonic superfluidity in grapheneMay 21 2013Dec 06 2013We discuss the conditions under which the predicted (but not yet observed) zero-field interlayer excitonic condensation in double layer graphene has a critical temperature high enough to allow detection. Crucially, disorder arising from charged impurities ... More

Sucralose Interaction with Protein StructuresJul 14 2017Jul 23 2017Sucralose is a commonly employed artificial sweetener that appears to destabilize protein native structures. This is in direct contrast to the bio-preservative nature of its natural counterpart, sucrose, which enhances the stability of biomolecules against ... More

Retardation of Bulk Water Dynamics by Disaccharide OsmolytesJul 21 2016The bioprotective nature of disaccharides is hypothesized to derive from the modification of the hydrogen bonding network of water which protects biomolecules through lowered water activity at the protein interface. Using ultrafast fluorescence spectroscopy ... More

Capillary stress and structural relaxation in moist granular materialsMar 15 2018Dec 24 2018We propose a theoretical framework to calculate capillary stresses in complex mesoporous materials, such as moist sand, nanoporous hydrates, and drying colloidal films. Molecular simulations are mapped onto a phase-field model of the liquid-vapor mixture, ... More

Auxiliary master equation approach within stochastic wave functions: Application to the Interacting Resonant Level ModelDec 05 2018Dec 11 2018We present further developments of the auxiliary master equation approach (AMEA), a numerical method to simulate many-body quantum systems in as well as out of equilibrium, and apply it to the Interacting Resonant Level Model (IRLM) to benchmark the new ... More

Teichmueller space via Kuranishi familiesFeb 15 2007Jan 13 2009We construct Teichmueller space by patching together Kuranishi families. We also discuss the basic properties of Teichmueller space, and in particular show that our construction leads to simplifications in the proof of Teichmueller's theorem asserting ... More

A rigidity property of local cohomology modulesNov 09 2015The relationships between the invariants and the homological properties of $I$, ${\rm Gin}(I)$ and $I^{\rm lex}$ have been studied extensively over the past decades. A result of A. Conca, J. Herzog and T. Hibi points out some rigid behaviours of their ... More

Sequentially Cohen-Macaulay modules and local cohomologyJan 10 2001The main result of the paper states that for a graded ideal I in a polynomial ring R over a field of characteristic 0, the Hilbert functions of the local cohomology modules of R/I and of R/Gin(I) coincide if and only if R/I is sequentially Cohen-Macaulay. ... More

Compressive Signal Processing with Circulant Sensing MatricesMar 12 2014Compressive sensing achieves effective dimensionality reduction of signals, under a sparsity constraint, by means of a small number of random measurements acquired through a sensing matrix. In a signal processing system, the problem arises of processing ... More

Nonlocal diffusion and applicationsApr 30 2015Jun 30 2016We consider the fractional Laplace framework and provide models and theorems related to nonlocal diffusion phenomena. Some applications are presented, including: a simple probabilistic interpretation, water waves, crystal dislocations, nonlocal phase ... More

Fitting Neutrino Physics with a U(1)_R Lepton NumberMar 23 2012Apr 03 2012We study neutrino physics in the context of a supersymmetric model where a continuous R-symmetry is identified with the total Lepton Number and one sneutrino can thus play the role of the down type Higgs. We show that R-breaking effects communicated to ... More

Possible Indications of New Physics in Bd-mixing and in sin(2 beta) DeterminationsMar 30 2008Jul 08 2008Using the hadronic matrix elements from the lattice, B_K and xi_s, involving only the 4-quark operators for Delta flavor (F) = 2 Hamiltonian relevant for K, B_d and B_s mixing, along with V_cb, we deduce a non-trivial constraint on the SM, sin (2 beta) ... More

Fast and Lightweight Rate Control for Onboard Predictive Coding of Hyperspectral ImagesJan 30 2017Predictive coding is attractive for compression of hyperspecral images onboard of spacecrafts in light of the excellent rate-distortion performance and low complexity of recent schemes. In this letter we propose a rate control algorithm and integrate ... More

New ways to TeV scale leptogenesisMay 27 2013Jul 31 2013We show that by adding to the standard model plus the type I seesaw different types of scalars, it is possible to construct models that satisfy the three requirements of (i) generating neutrino masses at the TeV scale, (ii) being testable at the LHC via ... More

Temporally Resolved Intensity Contouring (TRIC) for characterization of the absolute spatio-temporal intensity distribution of a relativistic, femtosecond laser pulseSep 16 2018Today's high-power laser systems are capable of reaching photon intensities up to $10^{22}$ W/cm^2, generating plasmas when interacting with material. The high intensity and ultrashort laser pulse duration (fs) make direct observation of plasma dynamics ... More

Continuity and density results for a one-phase nonlocal free boundary problemApr 21 2015Mar 01 2016We consider a one-phase nonlocal free boundary problem obtained by the superposition of a fractional Dirichlet energy plus a nonlocal perimeter functional. We prove that the minimizers are H\"older continuous and the free boundary has positive density ... More

Tunable chirality and circular dichroism of a topological insulator with $ C_{2v} $ symmetry as a function of Rashba and Dresselhaus parametersAug 19 2015Aug 26 2015Polarization-sensitive devices rely on meta-materials to exhibit varying degrees of absorption of light of a given handedness. The chiral surface states of a topological insulator(TI) selectively absorb right and left circularly polarized light in the ... More

An improved observable for the forward-backward asymmetry in B -> K* l+ l- and Bs -> phi l+ l-Jul 22 2010We study the decay B -> K* l+ l- in the QCD factorization approach and propose a new integrated observable whose dependence on the form factors is almost negligible, consequently the non--perturbative error is significantly reduced and indeed its overall ... More

Two remarks on the Weierstrass flagApr 30 2012We show that the locally closed strata of the Weierstrass flags on the moduli spaces of curves of genus g and on the moduli space of curves of genus g with one marked point are almost never affine.

Hadronic total cross sections, Wilson loop correlators and the QCD spectrumSep 25 2014We show how to obtain rising hadronic total cross sections in QCD, in the framework of the nonperturbative approach to soft high-energy scattering based on Wilson-loop correlators. Total cross sections turn out to be of "Froissart"-type, i.e., the leading ... More

Equivalence of two different notions of tangent bundle on rectifiable metric measure spacesNov 29 2016We prove that for a suitable class of metric measure spaces, the abstract notion of tangent module as defined by the first author can be isometrically identified with the space of $L^2$-sections of the `Gromov-Hausdorff tangent bundle'. The class of spaces ... More

Well-posedness of semilinear stochastic wave equations with Hölder continuous coefficientsJun 30 2016We prove that semilinear stochastic abstract wave equations, including wave and plate equations, are well-posed in the strong sense with an $\alpha$-H\"{o}lder continuous drift coefficient, if $\alpha \in (2/3,1)$. The uniqueness may fail for the corresponding ... More

Binary adaptive embeddings from order statistics of random projectionsJan 30 2017We use some of the largest order statistics of the random projections of a reference signal to construct a binary embedding that is adapted to signals correlated with such signal. The embedding is characterized from the analytical standpoint and shown ... More

Radial coherent and intelligent states of paraxial wave equationNov 17 2012Ladder operators for the radial index of the paraxial optical modes in the cylindrical coordinates are calculated. The operators obey the su(1,1) algebra commutation relations. Based on this Lie algebra, we found that coherent modes constructed as eigenstates ... More

Reparametrizing loop entropy weights: Effect on DNA melting curvesDec 18 2002Jan 06 2004Recent advances in the understanding of the melting behavior of double-stranded DNA with statistical mechanics methods lead to improved estimates of the weight factors for the dissociation events of the chains, in particular for interior loop melting. ... More

Improved chemical vapor transport growth of transition metal dichalcogenidesJan 22 2014In the crystal growth of transition metal dichalcogenides by the Chemical Vapor Transport method (CVT), the choice of the transport agent plays a key role. We have investigated the effect of various chemical elements and compounds on the growth of TiSe2, ... More

Regularity properties of nonlocal minimal surfaces via limiting argumentsMay 05 2011Feb 06 2013We prove an improvement of flatness result for nonlocal minimal surfaces which is independent of the fractional parameter $s$ when $s\rightarrow 1^-$. As a consequence, we obtain that all the nonlocal minimal cones are flat and that all the nonlocal minimal ... More

Implications of B -> rho gamma measurements in the Standard Model and Supersymmetric TheoriesJun 25 2002Sep 12 2002We study the implications of the recently improved upper limits on the branching ratios for the decays B -> rho gamma, expressed as R(rho gamma/K^* gamma) = BR(B -> rho gamma)/BR(B -> K^* gamma) <0.047. We work out the constraints that the current bound ... More

Remarks on the static dipole-dipole potential at large distancesJul 26 2015Nov 03 2015We determine the large-distance behaviour of the static dipole-dipole potential for a wide class of gauge theories on nonperturbative grounds, exploiting only general properties of the theory. In the case of QCD, we recover the known results in the regime ... More

High-energy hadron-hadron (dipole-dipole) scattering on the latticeOct 05 2010We will discuss how the problem of high-energy hadron-hadron (dipole-dipole) scattering at low momentum transfer can be approached from the point of view of lattice QCD, by means of Monte Carlo numerical simulations.

A primer on Carnot groups: homogenous groups, CC spaces, and regularity of their isometriesApr 28 2016Carnot groups are distinguished spaces that are rich of structure: they are those Lie groups equipped with a path distance that is invariant by left-translations of the group and admit automorphisms that are dilations with respect to the distance. We ... More

Lipschitz and path isometric embeddings of metric spacesMay 10 2010Feb 16 2016We prove that each sub-Riemannian manifold can be embedded in some Euclidean space preserving the length of all the curves in the manifold. The result is an extension of Nash $C^1$ Embedding Theorem. For more general metric spaces the same result is false, ... More

Diffeomorphic vs isotopic links in lens spacesJan 07 2017Links in lens spaces may be defined to be equivalent by ambient isotopy or by diffeomorphism of pairs. In the first case, for all the combinatorial representations of links, there is a set of Reidemeister-type moves on diagrams connecting isotopy equivalent ... More

Abelian Carter subgroups in finite permutation groupsMay 27 2013May 28 2013We show that a finite permutation group containing a regular abelian self-normalizing subgroup is soluble.

Widespread presence of shallow cusps in the surface-brightness profile of globular clustersAug 16 2010Surface brightness profiles of globular clusters with shallow central cusps (Sigma ~ R^v with -0.3<~ v <~ -0.05) have been associated by several recent studies with the presence of a central intermediate mass black hole (IMBH). Such shallow slopes are ... More

Bosons and EnvironmentJun 27 2000The role of background in bosonic quantum statistics is discussed in the frame of a new approach in terms of coherent states. Bosons are indeed detected in different physical situations where they exhibit different and apparently unconnected properties. ... More

The asymptotic Schottky problemNov 25 2008Let $\mathcal M_g$ denote the moduli space of compact Riemann surfaces of genus $g$ and let $\mathcal A_g$ be the space of principally polarized abelian varieties of (complex) dimension $g$. Let $J:\mathcal M_g\longrightarrow \mathcal A_g$ be the map ... More

Is There Flavour Independence in Tensor Glueball Decays?Apr 19 2014The flavour independence hypothesis for (tensor) glueball decays into exclusive final states is not ruled out by the existing data. A new methodology for testing its validity and accuracy is proposed in the framework of a particular mixing scheme. As ... More

Probability matrices, non-negative rank, and parameterizations of mixture modelsNov 02 2009Nov 09 2009In this paper we parameterize non-negative matrices of sum one and rank at most two. More precisely, we give a family of parameterizations using the least possible number of parameters. We also show how these parameterizations relate to a class of statistical ... More

Doubling property for biLipschitz homogeneous geodesic surfacesNov 02 2008Feb 16 2016In this paper we discuss general properties of geodesic surfaces that are locally biLipschitz homogeneous. In particular, we prove that they are locally doubling and that there exists a special doubling measure analogous to the Haar measure for locally ... More

Natural R Parity Conservation with Horizontal Symmetries. a Four Generation ModelNov 08 1994Mar 29 1995In most supersymmetric models the stability of the proton is ensured by invoking R-parity. A necessary ingredient to enforce R-parity is the possibility of distinguishing the lepton superfields from the Higgs ones. This is generally achieved either by ... More

On computing fixed points for generalized sandpilesDec 11 2004We prove fixed points results for sandpiles starting with arbitrary initial conditions. We give an effective algorithm for computing such fixed points, and we refine it in the particular case of SPM.

Getting acquainted with the fractional LaplacianOct 31 2017Jan 29 2018These are the handouts of an undergraduate minicourse at the Universit\`a di Bari, in the context of the 2017 INdAM Intensive Period "Contemporary Research in elliptic PDEs and related topics". Without any intention to serve as a throughout epitome to ... More

A Generalization of the Space-Fractional Poisson Process and its Connection to some Lévy ProcessesFeb 10 2015Jan 08 2016This paper introduces a generalization of the so-called space-fractional Poisson process by extending the difference operator acting on state space present in the associated difference-differential equations to a much more general form. It turns out that ... More

Gradient estimates for a class of anisotropic nonlocal operatorsSep 23 2018Sep 26 2018Using a classical technique introduced by Achi E. Brandt for elliptic equations, we study a general class of nonlocal equations obtained as a superposition of classical and fractional operators in different variables. We obtain that the increments of ... More

Fibered knots and links in lens spacesFeb 11 2015We take advantage of the correspondence between fibered links, open book decompositions and contact structures on a closed connected 3-dimensional manifold to determine a mixed link diagram presentation for a particular fibered link $L$ in the lens space ... More

Footprints of the Beyond in flavor physics: Possible role of the Top Two Higgs Doublet ModelJul 01 2007The B-factories results provide an impressive confirmation of the Standard Model (SM) description of flavor and CP violation. Nevertheless, as more data were accumulated, deviations in the 2.5-3.5 sigma range have emerged pointing to the exciting possibility ... More

Filling functions of arithmetic groupsOct 02 2017The Dehn function and its higher-dimensional generalizations measure the difficulty of filling a sphere in a space by a ball. In nonpositively curved spaces, one can construct fillings using geodesics, but fillings become more complicated in subsets of ... More

A spectral theory for solvable Lie algebras of operatorsMay 16 2015The main objective of this paper is to develop a notion of joint spectrum for complex solvable Lie algebras of operators acting on a Banach space, which generalizes the Taylor joint spectrum (T.J.S.) for several commuting operators.

Geometric control theory I: mathematical foundationsMay 16 2007May 15 2015A geometric setup for control theory is presented. The argument is developed through the study of the extremals of action functionals defined on piecewise differentiable curves, in the presence of differentiable non-holonomic constraints. Special emphasis ... More

Constrained variational calculus: the second variation (part I)Jun 18 2010Oct 16 2012Within the geometrical framework developed in arXiv:0705.2362, the problem of minimality for constrained calculus of variations is analysed among the class of differentiable curves. A fully covariant representation of the second variation of the action ... More

Singularities of moduli spaces of sheaves on K3 surfaces and Nakajima quiver varietiesMay 04 2015Jan 18 2016The aim of this paper is to study the singularities of certain moduli spaces of sheaves on K3 surfaces by means of Nakajima quiver varieties. The singularities in question arise from the choice of a non--generic polarization, with respect to which we ... More

Semi-Analytical Minimum Time Solution for the Optimal Control of a Vehicle subject to Limited AccelerationMar 20 2016Apr 10 2016The basic module for the solution of the minimum time optimal control of a car-like vehicle is herein presented. The vehicle is subject to the effect of laminar (linear) and aerodynamic (quadratic) drag, taking into account the asymmetric bounded longitudinal ... More

Spin-orbit coupling mediated tunable electron heat capacity of quantum wellsAug 13 2016Aug 16 2016The heat capacity of conduction electrons obtained from the Sommerfeld expansion is shown to be tunable via the Rashba and Dresselhaus spin-orbit coupling parameters. Using an AlInSb/InSb/AlInSb as a representative heterostructure with alterable well ... More

Scattering times and mobility with localized impurities in topological insulator filmsMay 19 2015The zero gap surface states of a 3D-topological insulator host highly mobile Dirac fermions with spin locked to the momentum. The high mobility attributed to absence of back scattering is reduced in presence of impurities on the surface. In particular, ... More

Demise of CKM & its aftermathApr 12 2011Jun 27 2011Using firmly established experimental inputs such as epsilon_K, Delta M_d, Delta M_s, BR(B -> tau nu), gamma, V_cb along with corresponding lattice matrix elements which have been well studied and are in full QCD such as B_K, SU3 breaking ratio xi, B_Bs ... More

Monomials as sum of k-th powers of formsMay 20 2013Motivated by recent results on the Waring problem for polynomial rings and representation of monomial as sum of powers of linear forms, we consider the problem of presenting monomials of degree kd as sums of k-th powers of forms of degree d. We produce ... More

On the KBSM of links in lens spacesJun 03 2015In this paper the properties of the Kauffman bracket skein module of $L(p,q)$ are investigated. Links in lens spaces are represented both through band and disk diagrams. The possibility to transform between the diagrams enables us to compute the Kauffman ... More

On modifications of the exponential integral with the Mittag-Leffler functionJan 29 2019In this paper we survey the properties of the Schelkunoff modification of the Exponential integral and we generalize it with the Mittag-Leffler function. So doing we get a new special function (as far as we know) that may be relevant in linear viscoelasticity ... More

Multiple Intelligences and quotient spacesNov 02 2006The Multiple Intelligence Theory (MI) is one of the models that study and describe the cognitive abilities of an individual. In [7] is presented a referential system which allows to identify the Multiple Intelligences of the students of a course and to ... More

Blowing in the Milky Way wind: neutral hydrogen clouds tracing the Galactic nuclear outflowFeb 06 2018We present the results of a new sensitive survey of neutral hydrogen above and below the Galactic Center with the Green Bank Telescope. The observations extend up to Galactic latitude | b | < 10 deg with an effective angular resolution of 9.5' and an ... More

Gas accretion from minor mergers in local spiral galaxiesJun 03 2014In this paper we quantify the gas accretion rate from minor mergers onto star-forming galaxies in the Local Universe using HI observations of 148 nearby spiral galaxies (WHISP sample). We developed a dedicated code that iteratively analyses HI data-cubes, ... More

On the Link Between Energy Equipartition and Radial Variation in the Stellar Mass Function of Star ClustersSep 28 2016We make use of $N$-body simulations to determine the relationship between two observable parameters that are used to quantify mass segregation and energy equipartition in star clusters. Mass segregation can be quantified by measuring how the slope of ... More

Stochastic and deterministic modelling of cell migrationJun 18 2018Aug 15 2018Mathematical models are vital interpretive and predictive tools used to assist in the understanding of cell migration. There are typically two approaches to modelling cell migration: either micro-scale, discrete or macro-scale, continuum. The discrete ... More

On the rate of convergence to the asymptotic cone for nilpotent groups and subFinsler geometryApr 07 2012Addressing a question of Gromov, we give a rate in Pansu's theorem about the convergence in Gromov-Hausdorff metric of a finitely generated nilpotent group equipped with a left-invariant word metric scaled by a factor 1/n towards its asymptotic cone. ... More

Geometric Constrained Variational Calculus. I. - Piecewise smooth extremalsMar 30 2015A geometric setup for constrained variational calculus is presented. The analysis deals with the study of the extremals of an action functional defined on piecewise differentiable curves, subject to differentiable, non-holonomic constraints. Special attention ... More

A Sharp Liouville Theorem for Elliptic OperatorsFeb 16 2010We introduce a new condition on elliptic operators $L= {1/2}\triangle + b \cdot \nabla $ which ensures the validity of the Liouville property for bounded solutions to $Lu=0$ on $\R^d$. Such condition is sharp when $d=1$. We extend our Liouville theorem ... More

Vertex corrections of impurity scattering at a ferromagnetic quantum critical pointApr 01 2009We study the renormalization of a non-magnetic impurity's scattering potential due to the presence of a massless collective spin mode at a ferromagnetic quantum critical point. To this end, we compute the lowest order vertex corrections in two- and three-dimensional ... More

Observational Constraints on Gauge Field Production in Axion InflationMar 27 2012Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of the observational ... More

Remarks about Besicovitch covering property in Carnot groups of step 3 and higherMar 31 2015We prove that the Besicovitch Covering Property (BCP) does not hold for some classes of homogeneous quasi-distances on Carnot groups of step 3 and higher. As a special case we get that, in Carnot groups of step 3 and higher, BCP is not satisfied for those ... More

Toward a quasi-Möbius characterization of Invertible Homogeneous Metric SpacesDec 08 2018We study locally compact metric spaces that enjoy various forms of homogeneity with respect to M\"obius self-homeomorphisms. We investigate connections between such homogeneity and the combination of isometric homogeneity with invertibility. In particular, ... More

On jet schemes of pfaffian idealsJan 28 2019Jet schemes and arc spaces received quite a lot of attention by researchers after their introduction, due to J. Nash, and established their importance as an object of study in M. Kontsevich's motivic integration theory. Several results point out that ... More

Norm discontinuity and spectral properties of Ornstein-Uhlenbeck semigroupsSep 14 2005Let $E$ be a real Banach space. We study the Ornstein-Uhlenbeck semigroup $P(t)$ associated with the Ornstein-Uhlenbeck operator $$ Lf(x) = \frac12 {\rm Tr} Q D^2 f(x) + <Ax, Df(x)>.$$ Here $Q$ is a positive symmetric operator from $E^*$ to $E$ and $A$ ... More

Blowups and blowdowns of geodesics in Carnot groupsJun 25 2018Oct 05 2018This paper provides some partial regularity results for geodesics (i.e., isometric images of intervals) in arbitrary sub-Riemannian and sub-Finsler manifolds. Our strategy is to study infinitesimal and asymptotic properties of geodesics in Carnot groups ... More

Conformal equivalence of visual metrics in pseudoconvex domainsMar 01 2017We refine estimates introduced by Balogh and Bonk, to show that the boundary extensions of isometries between smooth strongly pseudoconvex domains in $\C^n$ are conformal with respect to the sub-Riemannian metric induced by the Levi form. As a corollary ... More