Results for "Daniel Roberto Cassar"

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Solving the Classical Nucleation Theory with respect to the surface energyDec 15 2018A critical parameter of the Classical Nucleation Theory is the surface energy $\sigma$ between the nucleus and the ambient phase. Unfortunately, this parameter cannot be measured experimentally for crystal nucleation in condensed matter. A typical practice ... More
The failure of the Classical Nucleation Theory at low temperatures resolvedFeb 08 2019A relevant observation about crystal nucleation kinetics in glass-forming substances has been a matter of intense debate for several decades. The Classical Nucleation Theory (CNT) allegedly fails to describe the temperature dependence of the homogeneous ... More
Second Quantized Mathieu MoonshineDec 02 2013Nov 11 2014We study the second quantized version of the twisted twining genera of generalized Mathieu moonshine, and prove that they give rise to Siegel modular forms with infinite product representations. Most of these forms are expected to have an interpretation ... More
Fricke S-duality in CHL modelsApr 27 2015Sep 02 2015We consider four dimensional CHL models with sixteen spacetime supersymmetries obtained from orbifolds of type IIA superstring on K3 x T^2 by a Z_N symmetry acting (possibly) non-geometrically on K3. We show that most of these models (in particular, for ... More
Gradient algorithms for finding common Lyapunov functionsJun 18 2002This paper is concerned with the problem of finding a quadratic common Lyapunov function for a family of stable linear systems. We present gradient iteration algorithms which give deterministic convergence for finite system families and probabilistic ... More
Fricke S-duality in CHL modelsApr 27 2015Nov 21 2016We consider four dimensional CHL models with sixteen spacetime supersymmetries obtained from orbifolds of type IIA superstring on K3 x T^2 by a Z_N symmetry acting (possibly) non-geometrically on K3. We show that most of these models (in particular, for ... More
The cluster galaxy luminosity function at $z=0.3$: a recent origin for the faint-end upturn ?Jun 20 2007We derive deep luminosity functions (to $M_z=-15$) for galaxies in Abell 1835 ($z=0.25$) and AC 114 ($z=0.31$) and compare these with the local $z'$ luminosity function for 69 clusters. The data show that the faint-end upturn, the excess of galaxies above ... More
The luminosity function of galaxies to $M_{BgVriz} \sim -14$ in $z \sim 0.3$ clustersOct 23 2008We present deep composite luminosity functions in $B$, $g$, $V$, $r$, $i$ and $z$ for six clusters at $0.14 < z < 0.40$ observed with the Hubble Space Telescope Advanced Camera for Surveys. The luminosity functions reach to absolute magnitude of $\sim ... More
The evolution of cluster dwarfsAug 20 2009We summarize the results from analyzing six clusters of galaxies at 0.14 < z < 0.40 observed with the Hubble Space Telescope Advanced Camera for Surveys. We derive deep composite luminosity functions in B,g,V,r,i and z down to an absolute magnitude of ... More
The Virtual Diphoton ExcessJan 08 2016Jan 26 2016Interpreting the excesses around 750 GeV in the diphoton spectra to be the signal of a new heavy scalar decaying to photons, we point out the possibility of looking for correlated signals with virtual photons. In particular, we emphasize that the effective ... More
A Survey of Runtime Monitoring Instrumentation TechniquesAug 24 2017Runtime Monitoring is a lightweight and dynamic verification technique that involves observing the internal operations of a software system and/or its interactions with other external entities, with the aim of determining whether the system satisfies ... More
Dark Matter Searches: The Nightmare ScenarioJul 28 2011Jan 04 2012The unfortunate case where the Large Hadron Collider (LHC) fails to discover physics Beyond the Standard Model (BSM) is sometimes referred to as the "Nightmare scenario" of particle physics. We study the consequences of this hypothetical scenario for ... More
Mott transition in lattice boson modelsSep 26 2005Jan 19 2006We use mathematically rigorous perturbation theory to study the transition between the Mott insulator and the conjectured Bose-Einstein condensate in a hard-core Bose-Hubbard model. The critical line is established to lowest order in the tunneling amplitude. ... More
Quantum Noise Limits for Nonlinear, Phase-Invariant AmplifiersJul 03 1994Any quantum device that amplifies coherent states of a field while preserving their phase generates noise. A nonlinear, phase-invariant amplifier may generate less noise, over a range of input field strengths, than any linear amplifier with the same amplification. ... More
Controlling self-organized criticality in complex networksMay 28 2013A control scheme to reduce the size of avalanches of the Bak-Tang-Wiesenfeld model on complex networks is proposed. Three network types are considered: those proposed by Erd\H{o}s-Renyi, Goh-Kahng-Kim, and a real network representing the main connections ... More
Universal Deformation Rings and Quivers of Finite Representation TypeApr 03 2016Let k be a field of arbitrary characteristic and let Q be a quiver of finite representation type. In this paper we prove that if M is an indecomposable kQ-module then the universal deformation ring of M over kQ is isomorphic to k.
Jacob's Ladder: Prime numbers in 2dDec 19 2017Jul 07 2018Prime numbers are one of the most intriguing figures in mathematics. Despite centuries of research, many questions remain still unsolved. In recent years, computer simulations are playing a fundamental role in the study of an immense variety of problems. ... More
Parallel-in-Space-and-Time Simulation of the Three-Dimensional, Unsteady Navier-Stokes Equations for Incompressible FlowMay 17 2017In this paper we combine the Parareal parallel-in-time method together with spatial parallelization and investigate this space-time parallel scheme by means of solving the three-dimensional incompressible Navier-Stokes equations. Parallelization of time ... More
Performance vs complexity trade-offs for Markovian networked jump estimatorsMar 20 2014This paper addresses the design of a state observer for networked systems with random delays and dropouts. The model of plant and network covers the cases of multiple sensors, out-of-sequence and buffered measurements. The measurement outcomes over a ... More
Golden Probe of the Top YukawaDec 24 2015We describe how the Higgs decay to four leptons can be used to probe the nature and $CP$ structure of the top Yukawa coupling.
A dynamical programming approach for controlling the directed abelian Dhar-Ramaswamy modelMay 29 2013A dynamical programming approach is used to deal with the problem of controlling the directed abelian Dhar-Ramaswamy model on two-dimensional square lattice. Two strategies are considered to obtain explicit results to this task. First, the optimal solution ... More
Controlling self-organized criticality in sandpile modelsMay 28 2013We introduce an external control to reduce the size of avalanches in some sandpile models exhibiting self organized criticality. This rather intuitive approach seems to be missing in the vast literature on such systems. The control action, which amounts ... More
Monstrous BPS-Algebras and the Superstring Origin of MoonshineJan 20 2016Jun 06 2016We provide a physics derivation of Monstrous moonshine. We show that the McKay-Thompson series $T_g$, $g\in \mathbb{M}$, can be interpreted as supersymmetric indices counting spacetime BPS-states in certain heterotic string models. The invariance groups ... More
Generalised Moonshine and Holomorphic OrbifoldsFeb 21 2013Generalised moonshine is reviewed from the point of view of holomorphic orbifolds, putting special emphasis on the role of the third cohomology group H^3(G, U(1)) in characterising consistent constructions. These ideas are then applied to the case of ... More
Lattice formulation of axion inflation. Application to preheatingDec 07 2018We present a lattice formulation of an interaction ${\phi\over\Lambda} F\tilde F$ between an axion and some $U(1)$ gauge sector with the following properties: it reproduces the continuum theory up to $\mathcal{O}(dx_\mu^2)$ corrections, it preserves exact ... More
Representation Learning for Visual-Relational Knowledge GraphsSep 07 2017Mar 31 2018A visual-relational knowledge graph (KG) is a multi-relational graph whose entities are associated with images. We introduce ImageGraph, a KG with 1,330 relation types, 14,870 entities, and 829,931 images. Visual-relational KGs lead to novel probabilistic ... More
Interpretations of Quantum Theory in the Light of Modern CosmologyDec 24 2014The difficult issues related to the interpretation of quantum mechanics and, in particular, the "measurement problem" are revisited using as motivation the process of generation of structure from quantum fluctuations in inflationary cosmology. The unessential ... More
Mapping dynamical systems onto complex networksOct 30 2006Apr 24 2007A procedure to characterize chaotic dynamical systems with concepts of complex networks is pursued, in which a dynamical system is mapped onto a network. The nodes represent the regions of space visited by the system, while edges represent the transitions ... More
Simulating Organogenesis in COMSOL: Phase-Field Based Simulations of Embryonic Lung Branching MorphogenesisOct 28 2016Organogenesis has been studied for decades, but fundamental questions regarding the control of growth and shape remain unsolved. We have recently shown that of all proposed mathematical models only ligand-receptor based Turing models successfully reproduce ... More
Study of the one-dimensional off-lattice hot-monomer reaction modelMay 04 1999Oct 21 1999Hot monomers are particles having a transient mobility (a ballistic flight) prior to being definitely absorbed on a surface. After arriving at a surface, the excess energy coming from the kinetic energy in the gas phase is dissipated through degrees of ... More
Starspots and spin-orbit alignment for Kepler cool host starsNov 08 2012The angle between the spin axis of the host star and the orbit of its planets (i.e., the stellar obliquity) is precious information about the formation and evolution of exoplanetary systems. Measurements of the Rossiter-McLaughlin effect revealed that ... More
Generalised Mathieu MoonshineNov 29 2012Jan 16 2014The Mathieu twisted twining genera, i.e. the analogues of Norton's generalised Moonshine functions, are constructed for the elliptic genus of K3. It is shown that they satisfy the expected consistency conditions, and that their behaviour under modular ... More
Starvation as the primary quenching mechanism in galaxiesNov 22 2018Star-forming galaxies can in principle be transformed into passive systems by a multitude of processes that quench star formation, such as the halting of gas accretion or the rapid removal of gas in AGN-driven outflows. However, it remains unclear which ... More
Multiwavelength Study of X-ray Selected Star Forming Galaxies within the Chandra Deep Field SouthMay 09 2007We have combined multi-wavelength observations of a selected sample of starforming galaxies with galaxy evolution models in order to compare the results obtained for different SFR tracers and to study the effect that the evolution of the starforming regions ... More
Energetics and carrier transport in doped Si/SiO2 quantum dotsDec 01 2015In the present theoretical work we have considered impurities, either boron or phosphorous, located at different substitutional sites in silicon quantum dots (Si-QDs) with diameters around 1.5\,nm, embedded in a SiO2 matrix. Formation energy calculations ... More
Non-Unitary Neutrino Propagation From Neutrino DecayJul 24 2014Feb 12 2015Neutrino propagation in space-time is not constrained to be unitary if very light states - lighter than the active neutrinos - exist into which neutrinos may decay. If this is the case, neutrino flavor-change is governed by a handful of extra mixing and ... More
Low Level Control of a Quadrotor with Deep Model-Based Reinforcement learningJan 11 2019Generating low-level robot controllers often requires manual parameters tuning and significant system knowledge, which can result in long design times for highly specialized controllers. With the growth of automation, the need for such controllers might ... More
Gamma-ray detection from gravitino dark matter decay in the $μν$SSMJun 19 2009Feb 25 2010The $\mu\nu$SSM provides a solution to the $\mu$-problem of the MSSM and explains the origin of neutrino masses by simply using right-handed neutrino superfields. Given that R-parity is broken in this model, the gravitino is a natural candidate for dark ... More
Clustering and descendants of MUSYC galaxies at z<1.5Jun 29 2010Jul 07 2010We measure the evolution of galaxy clustering out to a redshift of z~1.5 using data from two MUSYC fields, the Extended Hubble Deep Field South (EHDF-S) and the Extended Chandra Deep Field South (ECDF-S). We use photometric redshift information to calculate ... More
Golden Probe of Electroweak Symmetry BreakingAug 06 2016The ratio of the Higgs couplings to $WW$ and $ZZ$ pairs, $\lambda_{WZ}$, is a fundamental parameter in electroweak symmetry breaking as well as a measure of the (approximate) custodial symmetry possessed by the gauge boson mass matrix. We show that Higgs ... More
Direct numerical simulations of Taylor--Couette turbulence: the effect of sand grain roughnessDec 05 2018Progress in roughness research, mapping any given roughness geometry to its fluid dynamic behaviour, has been hampered by the lack of accurate and direct measurements of skin-friction drag, especially in open systems. The Taylor--Couette (TC) system has ... More
Building your path to escape from homeSep 29 2017Feb 02 2019Random walks on dynamic graphs have received increasingly more attention from different academic communities over the last decade. Despite the relatively large literature, little is known about random walks that construct the graph where they walk while ... More
A Bayesian Analysis of the Constrained NMSSMJun 26 2009We perform a first global exploration of the Constrained Next-to-Minimal Supersymmetric Standard Model using Bayesian statistics. We derive several global features of the model and find that, in some contrast to initial expectations, they closely resemble ... More
Building your path to escape from homeSep 29 2017Random walks on dynamic graphs have received increasingly more attention over the last decade from different academic communities. Despite the relatively large literature very little is known about random walks that construct the graph where they walk ... More
Looking for the left sneutrino LSP with displaced-vertex searchesMar 30 2018Oct 01 2018We analyze a displaced dilepton signal expected at the LHC for a tau left sneutrino as the lightest supersymmetric particle with a mass in the range $45$-$100$ GeV. The sneutrinos are pair produced via a virtual $W$, $Z$ or $\gamma$ in the $s$ channel ... More
Diagrammatic Coupled Cluster Monte CarloJan 09 2019Feb 05 2019We propose a modified coupled cluster Monte Carlo algorithm that stochastically samples connected terms within the truncated Baker--Campbell--Hausdorff expansion of the similarity transformed Hamiltonian by construction of coupled cluster diagrams on ... More
Diagrammatic Coupled Cluster Monte CarloJan 09 2019Feb 09 2019We propose a modified coupled cluster Monte Carlo algorithm that stochastically samples connected terms within the truncated Baker--Campbell--Hausdorff expansion of the similarity transformed Hamiltonian by construction of coupled cluster diagrams on ... More
Is light neutralino as dark matter still viable?Jul 08 2011Motivated by the recent re-confirmation by CoGENT of the low-energy excess of events observed last year, and the recent improved limits from the XENON-100 experiment that are in contention with the CoGENT data, we re-examine the low mass neutralino region ... More
Analysis of the parameter space and spectrum of the $μν$SSMOct 08 2008Dec 04 2008The $\mu\nu$SSM is a supersymmetric standard model that solves the $\mu$ problem of the MSSM using the R-parity breaking couplings between the right-handed neutrino superfields and the Higgses in the superpotential, $\lambda_{i} \hat \nu^c_i \hat H_d ... More
Learning Power Spectrum Maps from Quantized Power MeasurementsJun 07 2016Using power measurements collected by a network of low-cost sensors, power spectral density (PSD) maps are constructed to capture the distribution of RF power across space and frequency. Linearly compressed and quantized power measurements enable wideband ... More
Probing the "$μ$ from $ν$" supersymmetric standard model with displaced multileptons from the decay of a Higgs boson at the LHCNov 14 2012Jun 17 2013The "$\mu$ from $\nu$" supersymmetric standard model ($\mu\nu$SSM) cures the $\mu$-problem and concurrently reproduces measured neutrino data by using a set of usual right-handed neutrino superfields. Recently, the LHC has revealed the first scalar boson ... More
A Multi-Wavelength Study of Low Redshift Clusters of Galaxies I. Comparison of X-ray and Mid-Infrared Selected AGNsJan 04 2011Clusters of galaxies have long been used as laboratories for the study of galaxy evolution, but despite intense, recent interest in feedback between AGNs and their hosts, the impact of environment on these relationships remains poorly constrained. We ... More
Mapping of focused Laguerre-Gauss beams: The interplay between spin and orbital angular momentum and its dependence on detector characteristicsApr 19 2012We show that propagating optical fields bearing an axial symmetry are not truly hollow in spite of a null electric field on-axis. The result, obtained by general arguments based upon the vectorial nature of electromagnetic fields, is of particular significance ... More
TransRev: Modeling Reviews as Translations from Users to ItemsJan 30 2018Apr 18 2018The text of a review expresses the sentiment a customer has towards a particular product. This is exploited in sentiment analysis where machine learning models are used to predict the review score from the text of the review. Furthermore, the products ... More
Post-processing the VLTI fringe-tracking data: First measurements of starsDec 12 2008At the Very Large Telescope Interferometer, the purpose of the fringe-tracker FINITO is to stabilize the optical path differences between the beams, allowing longer integration times on the scientific instruments AMBER and MIDI. Our goal is to demonstrate ... More
On the Detectability of the SZ Effect of Massive Young GalaxiesNov 07 2003The Sunyaev-Zel'dovich (SZ) effect expected to be associated with massive star-formation activity produced during the formation of the most luminous bulges of normal galaxies is discussed. Using 1-D chemohydrodynamical models for spheroidal galaxy evolution ... More
Extinction in the Star Cluster SAI~113 and Galactic Structure in CarinaJan 28 2017Photometric CCD {\it UBVI}$_C$ photometry obtained for 4860 stars surrounding the embedded southern cluster SAI~113 (Skiff~8) is used to examine the reddening in the field and derive the distance to the cluster and nearby van~Genderen~1. Spectroscopic ... More
The effect of a wider initial separation on common envelope binary interaction simulationsMar 07 2016Sep 16 2016We present hydrodynamic simulations of the common envelope binary interaction between a giant star and a compact companion carried out with the adaptive mesh refinement code ENZO and the smooth particle hydrodynamics code PHANTOM. These simulations mimic ... More
Topology classification with deep learning to improve real-time event selection at the LHCJun 29 2018Aug 01 2018We show how event topology classification based on deep learning could be used to improve the purity of data samples selected in real time at at the Large Hadron Collider. We consider different data representations, on which different kinds of multi-class ... More
Superconformal Vacua in N=2 Usp(4) Gauge TheoriesFeb 26 2004We study the dynamics of a confining vacuum in N=2 USp(4) gauge theory with n_f=4. The vacuum appears to be a deformed conformal theory with nonabelian gauge symmetry. The low-energy degrees of freedom consist of four nonabelian magnetic monopole doublets ... More
Hydrodynamic Simulations of the Interaction between an AGB Star and a Main Sequence Companion in Eccentric OrbitsOct 28 2015The Rotten Egg Nebula has at its core a binary composed of a Mira star and an A-type companion at a separation >10 au. It has been hypothesized to have formed by strong binary interactions between the Mira and a companion in an eccentric orbit during ... More
Integral field spectroscopy of HII regions in M33Dec 28 2012Integral field spectroscopy (IFS) is presented for star forming regions in M33. A central area of 300 x 500 pc^2 and the external HII region IC 132, at a galactocentric distance {\sim} 19arcmin (4.69 kpc) were observed with the Potsdam Multi Aperture ... More
Reset dynamics and latching in niobium superconducting nanowire single-photon detectorsAug 05 2010We study the reset dynamics of niobium (Nb) superconducting nanowire single-photon detectors (SNSPDs) using experimental measurements and numerical simulations. The numerical simulations of the detection dynamics agree well with experimental measurements, ... More
On the solutions of the Cartan equation in Metric Affine GravitySep 28 2000In the Tucker-Wang approach to Metric Affine gravity we review some particular solutions of the Cartan equation for the non-riemannian part of the connection. As application we show how a quite general non Riemannian model gives a Proca type equation ... More
Non-Invariant Ground States, Thermal Average, and generalized Fermionic StatisticsOct 11 1999Nov 09 1999We present an approach to generalised fermionic statistics which relates the existence of a generalised statistical behaviour to non-invariant ground states. Considering the thermal average of an operatorial generalization of the Heisenberg algebra, we ... More
The Prabhakar or three parameter Mittag--Leffler function: theory and applicationAug 24 2017Oct 11 2017The Prabhakar function (namely, a three parameter Mittag-Leffler function) is investigated. This function plays a fundamental role in the description of the anomalous dielectric properties in disordered materials and heterogeneous systems manifesting ... More
Observation of discrete gap solitons in binary waveguide arraysMay 08 2004We report on the first experimental observation of discrete gap solitons in binary arrays of optical waveguides. We observe the soliton generation when the inclination angle of an input beam is slightly above the Bragg angle, and show that the propagation ... More
Search for sharp and smooth spectral signatures of $μν$SSM gravitino dark matter with Fermi-LATAug 30 2016The $\mu\nu$SSM solves the $\mu$ problem of supersymmetric models and reproduces neutrino data, simply using couplings with right-handed neutrinos $\nu$'s. Given that these couplings break explicitly $R$ parity, the gravitino is a natural candidate for ... More
Local trace formulae for commuting Hamiltonians in Töplitz quantizationDec 12 2014Jan 10 2015Let $(M,J,\omega)$ be a quantizable compact K\"ahler manifold, with quantizing Hermitian line bundle $(A,h)$, and associated Hardy space $H(X)$, where $X$ is the unit circle bundle. Given a collection of $r$ Poisson commuting quantizable Hamiltonian functions ... More
Upper and lower bounds for the first eigenvalue and the volume entropy of noncompact Kähler manifoldsNov 12 2012Feb 02 2015We find upper and lower bounds for the first eigenvalue and the volume entropy of a noncompact real analytic K\"ahler manifold, in terms of Calabi's diastasis function and diastatic entropy, which are sharp in the case of the complex hyperbolic space. ... More
Anisotropic generalizations of de Sitter spacetimeApr 24 2002It is known that de Sitter spacetime can be seen as the solution of field equation for completely isotropic matter. In the present paper a new class of exact solutions in spherical symmetry is found and discussed, such that the energy--momentum tensor ... More
Effective lagrangians for QCD at high densityAug 27 2001We describe low energy physics in the CFL and LOFF phases by means of effective lagrangians. In the CFL case we present also how to derive expressions for the parameters appearing in the lagrangian via weak coupling calculations taking advantage of the ... More
Precision measurements at a muon colliderMay 10 2001This contribution describes precision width measurements that could be done at a muon collider for very narrow resonances as the Higgs or a possible pseudogoldstone boson, or for almost degenerate resonances as the A0 and H0 in the MSSM for large values ... More
A Theory of algebraic integrationSep 03 1998In this paper we study the problem of quantizing theories defined over a nonclassical configuration space. If one follows the path-integral approach, the first problem one is faced with is the one of definition of the integral over such spaces. We consider ... More
On the Ground State of QCD inside a Compact Stellar ObjectFeb 19 2007We describe the effects of the strange quark mass and of the color and electric neutrality on the superconducing phases of QCD.
QCD critical point: a historical perspectiveOct 14 2006We review the history of the critical point in the QCD phase diagram, baryon density vs. temperature. In particular we discuss the different theoretical approaches to this problem.
A theory of algebraic integrationDec 17 2001In this paper we extend the idea of integration to generic algebras. In particular we concentrate over a class of algebras, that we will call self-conjugated, having the property of possessing equivalent right and left multiplication algebras. In this ... More
An Analogue of the Kac-Wakimoto Formula and Black Hole Conditional EntropyMay 31 1996Jul 17 1997A local formula for the dimension of a superselection sector in Quantum Field Theory is obtained as vacuum expectation value of the exponential of the proper Hamiltonian. In the particular case of a chiral conformal theory, this provides a local analogue ... More
All-optical cooling of Fermi gases via Pauli inhibition of spontaneous emissionNov 19 2016A technique is proposed to cool Fermi gases to the regime of quantum degeneracy based on the expected inhibition of spontaneous emission due to the Pauli principle. The reduction of the linewidth for spontaneous emission originates a corresponding reduction ... More
Conformal Subnets and Intermediate SubfactorsFeb 26 2001Mar 05 2002Given an irreducible local conformal net A of von Neumann algebras on the circle and a finite-index conformal subnet B of A, we show that A is completely rational iff B is completely rational. In particular this extends a result of F. Xu for the orbifold ... More
A bounded homogeneous domain and a projective manifold are not relativesOct 04 2012Let $M_1$ and $M_2$ be two K\"ahler manifolds. One says that $M_1$ and $M_2$ are "relatives" if they share a non-trivial K\"ahler submanifold $S$, namely, if there exist two holomorphic and isometric immersions (K\"ahler immersions) $h_1: S -> M_1$ and ... More
Balanced metrics on homogeneous vector bundlesJan 16 2011Let $E\rightarrow M$ be a holomorphic vector bundle over a compact Kaehler manifold $(M, \omega)$ and let $E=E_1\oplus... \oplus E_m\rightarrow M$ be its decomposition into irreducible factors. Suppose that each $E_j$ admits a $\omega$-balanced metric ... More
Uniqueness of Eigenforms on Fractals-IIJan 27 2014Mar 31 2014I give an explicitly verifiable necessary and sufficient condition for the uniqueness of the eigenform on finitely ramified fractals, once an eigenform is known. This improves the results of my previous paper [14], where I gave some necessary and some ... More
Fixed Points of anti-attracting maps and Eigenforms on FractalsJan 08 2018An important problem in analysis on fractals is the existence of a self-similar energy on finitely ramified fractals. The self-similar energies are constructed in terms of eigenforms, that is, eigenvectors of a special nonlinear operator. Previous results ... More
(Bounded) continuous cohomology and Gromov proportionality principleMar 25 2009Apr 01 2010Let X be a topological space, and let C(X) be the complex of singular cochains on X with real coefficients. We denote by Cc(X) the subcomplex given by continuous cochains, i.e. by such cochains whose restriction to the space of simplices (endowed with ... More
Critical cones of characteristic varietiesAug 02 2010Jun 01 2011We show that certain characteristic varieties of a finitely generated module over a given Weyl algebra arising from weighted degree filtrations are equal to the critical cone of some other characteristic varieties. This behaviour of the characteristic ... More
Numerical evaluation of two and three parameter Mittag-Leffler functionsMar 23 2015May 21 2015The Mittag-Leffler (ML) function plays a fundamental role in fractional calculus but very few methods are available for its numerical evaluation. In this work we present a method for the efficient computation of the ML function based on the numerical ... More
Ultra High Energy Cosmic Rays: Origin, Composition and SpectrumDec 27 2018The physics of Ultra High Energy Cosmic Rays will be reviewed, discussing the latest experimental results and theoretical models aiming at explaining the observations in terms of spectra, mass composition and possible sources. It will be also discussed ... More
The Picard group of the universal abelian variety and the Franchetta conjecture for abelian varietiesMar 30 2016Apr 04 2016We compute the Picard group of the universal abelian variety over the moduli stack $\mathscr A_{g,n}$ of principally polarized abelian varieties over $\mathbb{C}$ with a symplectic principal level $n$-structure. We then prove that over $\mathbb{C}$ the ... More
Experimental Scattershot Boson SamplingMay 14 2015Boson Sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialised quantum computer. Current experimental schemes, however, are still insufficient ... More
A Three-Decade Outburst of the LMC Luminous Blue Variable R127 Draws to a CloseJul 09 2008The paradigmatic Luminous Blue Variable R127 in the Large Magellanic Cloud has been found in the intermediate, peculiar early-B state, and substantially fainter in visual light, signaling the final decline from its major outburst that began between 1978 ... More
Sub-arcsecond radio continuum mapping in and around the spiral galaxy NGC3351 using MERLINApr 26 2010We report sub-arcsecond scale radio continuum observations of a field of 35 by 22 arcmin centred in NGC3351 obtained with the Multi-Element Radio Linked Interferometer Network (MERLIN). We found 23 radio sources in this field, 6 of which are projected ... More
Gravitational collapse of homogeneous perfect fluid in HOG theoriesNov 27 2008This paper investigates the evolution of collapsing FRW models with a scalar field having the potential which arises in the conformal frame of high order gravity theories, coupled to matter described by a perfect fluid with energy density $\rho$ and pressure ... More
Gravitational collapse of homogeneous scalar fieldsJan 05 2005May 27 2005Conditions under which gravity coupled to self interacting scalar field determines singularity formation are found and discussed. It is shown that, under a suitable matching with an external space, the boundary, if collapses completely, may give rise ... More
On the independence of a generalized statement of Egoroff's theorem from ZFC, after T.WeissDec 23 2005We consider a generalized version (GES) of the wellknown Severini-Egoroff theorem in real analysis, first shown to be undecidable in ZFC by Tomasz Weiss. This independence is easily derived from suitable hypotheses on some cardinal characteristics of ... More
The impact of atomic precision measurements in high energy physicsJul 11 2000Jul 14 2000In this talk I discuss the relevance of atomic physics in understanding some important questions about elementary particle physics. A particular attention is devoted to atomic parity violation measurements which seem to suggest new physics beyond the ... More
The Bisognano-Wichmann Theorem for Charged States and the Conformal Boundary of a Black HoleJan 21 2000Recent applications of Operator Algebras to Quantum Field Theory on a Curved Spacetime show that the incremental entropy associated with a quantum black hole, due the addition of a short range charge, is quantized proportionally to the logarithm of an ... More
The Divergence Index: A Decomposable Measure of Segregation and InequalityAug 05 2015Dec 05 2016Decomposition analysis is a critical tool for understanding the social and spatial dimensions of inequality, segregation, and diversity. In this paper, I propose a new measure - the Divergence Index - to address the need for a decomposable measure of ... More
Semispectral Measures and Feller markov KernelsJun 30 2012Jul 22 2013We give a characterization of commutative semispectral measures by means of Feller and Strong Feller Markov kernels. In particular: {itemize} we show that a semispectral measure $F$ is commutative if and only if there exist a self-adjoint operator $A$ ... More
Dark Matter-baryon segregation in the non-linear evolution of coupled Dark Energy modelSep 13 2005Nov 30 2005The growth and virialization of spherical top-hat fluctuations, in coupled Dark Energy models, causes segregation between Dark Matter (DM) and baryons, as the gravitational infall into the potential well proceeds more slowly for the baryons than for DM. ... More