Results for "Daniel Roberto Cassar"

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Solving the Classical Nucleation Theory with respect to the surface energyDec 15 2018Mar 11 2019An essential parameter of the Classical Nucleation Theory (CNT) is the surface energy between a critical-size nucleus and the ambient phase, $\sigma$. In condensed matter, this parameter cannot be experimentally determined independently of CNT. A common ... 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
On Synchronous and Asynchronous Monitor Instrumentation for Actor-based systemsFeb 12 2015We study the impact of synchronous and asynchronous monitoring instrumentation on runtime overheads in the context of a runtime verification framework for actor-based systems. We show that, in such a context, asynchronous monitoring incurs substantially ... 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
Langevin dynamics of fluctuation induced first order phase transitions: self consistent Hartree ApproximationJul 07 2006The Langevin dynamics of a system exhibiting a Fluctuation Induced First Order Phase Transition is solved within the self consistent Hartree Approximation. Competition between interactions at short and long length scales gives rise to spatial modulations ... 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
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
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
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
A composite K-band Luminosity Function for Cluster GalaxiesAug 25 2009We present a composite K-band luminosity function for 10 clusters at low redshift, where member galaxies are identified from an existing spectroscopic survey (the 2dF galaxy redshift survey). Our kinematically selected K-band luminosity function is well ... 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
Improving Runtime Overheads for detectErMar 17 2015We design monitor optimisations for detectEr, a runtime-verification tool synthesising systems of concurrent monitors from correctness properties for Erlang programs. We implement these optimisations as part of the existing tool and show that they yield ... More
Golden Probe of the Top YukuwaMay 05 2015May 18 2015We perform a preliminary study of the ability of the Higgs decay to four leptons to shed light on the top quark Yukawa couplings. In particular we examine whether the $h\to 4\ell$ `golden channel' is sensitive to the $CP$ properties of the top quark couplings ... 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
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
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.
Generative Models For Deep Learning with Very Scarce DataMar 21 2019The goal of this paper is to deal with a data scarcity scenario where deep learning techniques use to fail. We compare the use of two well established techniques, Restricted Boltzmann Machines and Variational Auto-encoders, as generative models in order ... More
Developing Theoretical Foundations for Runtime EnforcementApr 24 2018Nov 12 2018The ubiquitous reliance on software systems increases the need for ensuring that systems behave correctly and are well protected against security risks. Runtime enforcement is a dynamic analysis technique that utilizes software monitors to check the runtime ... 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
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.
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
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
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
On Runtime Enforcement via SuppressionsJul 03 2018Runtime enforcement is a dynamic analysis technique that uses monitors to enforce the behaviour specified by some correctness property on an executing system. The enforceability of a logic captures the extent to which the properties expressible via the ... More
Reliability and Fault-Tolerance by Choreographic DesignAug 24 2017Distributed programs are hard to get right because they are required to be open, scalable, long-running, and tolerant to faults. In particular, the recent approaches to distributed software based on (micro-)services where different services are developed ... More
BPS Algebras, Genus Zero, and the Heterotic MonsterJan 18 2017In this note, we expand on some technical issues raised in \cite{PPV} by the authors, as well as providing a friendly introduction to and summary of our previous work. We construct a set of heterotic string compactifications to 0+1 dimensions intimately ... 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
On the Early Evolution of Young StarburstsMar 03 2009We studied the radio properties of very young massive regions of star formation in HII galaxies, with the aim of detecting episodes of recent star formation in an early phase of evolution where the first supernovae start to appear. The observed radio ... More
How old are the HII Galaxies?Nov 24 2003Using a novel approach we have reanalized the question of whether the extreme star forming galaxies known as HII galaxies are truly young or rejuvenated old systems. We first present a method of inversion that applies to any monotonic function of time ... 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
LUNA: Nuclear Astrophysics Deep UndergroundOct 20 2010Nuclear astrophysics strives for a comprehensive picture of the nuclear reactions responsible for synthesizing the chemical elements and for powering the stellar evolution engine. Deep underground in the Gran Sasso laboratory the cross sections of the ... More
Emission Line Properties of Seyfert 2 NucleiOct 26 2005Nov 16 2005We present a study of the global properties of Joguet's sample of 65 Seyfert 2 galaxies. We use the population synthesis models of our Paper II to derive `pure' emission-line spectra, and thus explore the statistical properties of the nuclear nebular ... 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
Learning Short-Cut Connections for Object CountingMay 08 2018Nov 15 2018Object counting is an important task in computer vision due to its growing demand in applications such as traffic monitoring or surveillance. In this paper, we consider object counting as a learning problem of a joint feature extraction and pixel-wise ... 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
Fusion of Head and Full-Body Detectors for Multi-Object TrackingMay 23 2017Apr 24 2018In order to track all persons in a scene, the tracking-by-detection paradigm has proven to be a very effective approach. Yet, relying solely on a single detector is also a major limitation, as useful image information might be ignored. Consequently, this ... 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
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
The evolution of superbubbles and the detection of Lyman alpha in star-forming galaxiesMay 25 1999The detection of Ly alpha emission in star-forming galaxies in different shapes and intensities (always smaller than predicted for case B recombination) has puzzled the astronomical community for more than a decade. Here we use two dimensional calculations ... More
Symmetry breaking in frustrated systems: effective fluctuation spectrum due to coupling effectsDec 28 2010We study the Langevin dynamics of a d-dimensional Ginzburg-Landau Hamiltonian with isotropic long range repulsive interactions. We show that, once the symmetry is broken, there is a coupling between the mean value of the local field and its fluctuations, ... More
Hunting physics beyond the standard model with unusual $W^\pm$ and $Z$ decaysMar 14 2014Feb 18 2015Nonstandard on-shell decays of $W^\pm$ and $Z$ bosons are possible within the framework of extended supersymmetric models, i.e., with singlet states and/or new couplings compared to the minimal supersymmetric standard model. These modes are typically ... 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
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
Probing the $μν$SSM with light scalars, pseudoscalars and neutralinos from the decay of a SM-like Higgs boson at the LHCOct 08 2014Nov 24 2014The "$\mu$ from $\nu$" supersymmetric standard model ($\mu\nu$SSM) can accommodate the newly discovered Higgs-like scalar boson with a mass around 125 GeV. This model provides a solution to the $\mu$-problem and simultaneously reproduces correct neutrino ... More
A novel approach to simulate gene-environment interactions in complex diseasesMay 07 2009Complex diseases are multifactorial traits caused by both genetic and environmental factors. They represent the most part of human diseases and include those with largest prevalence and mortality (cancer, heart disease, obesity, etc.). Despite of a large ... 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
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
Quantum enhanced measurements without entanglementJan 18 2017Apr 16 2018Quantum-enhanced measurements exploit quantum mechanical effects for increasing the sensitivity of measurements of certain physical parameters and have great potential for both fundamental science and concrete applications. Most of the research has so ... 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
Transition to ultimate Rayleigh-Bénard turbulence revealed through extended self similarity scaling analysis of the temperature structure functionsMay 01 2018In turbulent Rayleigh-B\'{e}nard (RB) convection, a transition to the so-called ultimate regime, in which the boundary layers (BL) are of turbulent type, has been postulated. Indeed, at very large Rayleigh number $Ra \approx 10^{13}-10^{14}$ a transition ... More
Deep Anomaly Detection for Generalized Face Anti-SpoofingApr 17 2019Face recognition has achieved unprecedented results, surpassing human capabilities in certain scenarios. However, these automatic solutions are not ready for production because they can be easily fooled by simple identity impersonation attacks. And although ... More
Extending Common Envelope Simulations from Roche Lobe Overflow to the Nebular PhaseSep 07 2018We have simulated a common envelope interaction of a 0.88-M$_{\odot}$, 90-R$_{\odot}$, red giant branch star and a 0.6-M$_{\odot}$, compact companion with the smoothed particle hydrodynamics code, Phantom, from the beginning of the Roche lobe overflow ... 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
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
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
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
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
Learning Flexible and Reusable Locomotion Primitives for a MicrorobotMar 01 2018The design of gaits for robot locomotion can be a daunting process which requires significant expert knowledge and engineering. This process is even more challenging for robots that do not have an accurate physical model, such as compliant or micro-scale ... More
The challenge of simultaneous object detection and pose estimation: a comparative studyJan 24 2018Detecting objects and estimating their pose remains as one of the major challenges of the computer vision research community. There exists a compromise between localizing the objects and estimating their viewpoints. The detector ideally needs to be view-invariant, ... 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
Optical/Near-IR spatially resolved study of the H II galaxy Tol 02Jul 21 2017The main goal of this study is to characterise the stellar populations in very low metallicity galaxies. We have obtained broad U, B, R, I, J, H, K, intermediate Str\"omgren y and narrow H{\alpha} and [OIII] deep images of the Wolf-Rayet, Blue Compact ... More
A new near-IR window of low extinction in the Galactic planeApr 20 2018The windows of low extinction in the Milky Way (MW) plane are rare but important because they enable us to place structural constraints on the opposite side of the Galaxy, which has hitherto been done rarely. We use the near-infrared (near-IR) images ... 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
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
Towards whole program generation of quadrature-free discontinuous Galerkin methods for the shallow water equationsApr 18 2019The shallow water equations (SWE) are a commonly used model to study tsunamis, tides, and coastal ocean circulation. However, there exist various approaches to discretize and solve them efficiently. Which of them is best for a certain scenario is often ... More
VLT Spectroscopy of Globular Cluster Systems, II. Spectroscopic Ages, Metallicities, and [alpha/Fe] Ratios of Globular Clusters in Early-Type GalaxiesMay 20 2005An analysis of ages, metallicities, and [alpha/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, Paper I of this series). In the light of calibration and measurement ... More
The compact, ~1 kpc host galaxy of a quasar at z=7.1Feb 13 2017We present ALMA observations of the [CII] fine structure line and the underlying far-infrared (FIR) dust continuum emission in J1120+0641, the most distant quasar currently known (z=7.1). We also present observations targeting the CO(2-1), CO(7-6) and ... More
Numerical simulations of flow reversal in Rayleigh--Bénard convectionDec 20 2006We investigate numerically the statistical properties of the large scale flow in Rayleigh--B\'enard convection. By using an external random perturbation on the temperature field, we were able to decrease the effective Prandtl number of the flow while ... More
Optimal photonic indistinguishability tests in multimode networksOct 10 2017Oct 11 2017Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications ... 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
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
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
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
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
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
Nonclassical dynamics of Bose condensates in an optical lattice in the superfluid regimeJun 14 2007A condensate in an optical lattice, prepared in the ground state of the superfluid regime, is stimulated first by suddenly increasing the optical lattice amplitude and then, after a waiting time, by abruptly decreasing this amplitude to its initial value. ... More
Majorana and the Infinite Component Wave EquationsOct 23 2006I review the paper of Majorana about relativistic particles with arbitrary spin written in 1932. The main motivation for this papers was the dissatisfaction about the negative energy solutions of the Dirac equation. As such, the paper became immediately ... More
Color Superconductivity in High Density QCDDec 15 2005Jan 18 2006We describe the effects of the strange quark mass and of color and electric neutrality on the superconducing phases of QCD. We discuss various phases pointing out the corresponding problems, typically arising from a chromomagnetic instability. We show ... More
Neumark Operators and Sharp Reconstructions, the finite dimensional caseMay 17 2010A commutative POV measure $F$ with real spectrum is characterized by the existence of a PV measure $E$ (the sharp reconstruction of $F$) with real spectrum such that $F$ can be interpreted as a randomization of $E$. This paper focuses on the relationships ... More
Bounded cohomology of discrete groupsOct 26 2016Bounded cohomology of groups was first defined by Johnson and Trauber during the seventies in the context of Banach algebras. As an independent and very active research field, however, bounded cohomology started to develop in 1982, thanks to the pioneering ... More
Automorphisms of the UHF algebra that do not extend to the Cuntz algebraMar 09 2010Automorphisms of the canonical core UHF-subalgebra F_n of the Cuntz algebra O_n do not necessarily extend to automorphisms of O_n. Simple examples are discussed within the family of infinite tensor products of (inner) automorphisms of the matrix algebras ... More
New Physics at the LHC: Strong vs Weak symmetry breakingAug 25 2009What kind of New Physics, if any, we expect to discover at the LHC? I will try to address this formidable question by re-formulating it as follows: is the breaking of the electroweak symmetry strong or weak ?
Neutrino mass variability due to nonminimal coupling to spacetime curvature in neutrinophilic two-Higgs-doublet modelsOct 18 2013In neutrinophilic two-Higgs-doublet models, neutrinos acquire mass due to a Higgs field with vacuum expectation value of the order of 10^{-2} eV, corresponding to a Compton wavelength in the 10 micrometer range. This creates a situation in which nonminimal ... More
Are quantum measurements on macroscopic bodies feasible?Mar 26 2010Mar 29 2010The possibility to test quantum measurement theories is discussed in the more phenomenological framework of the quantum nondemolition theory. A simple test of the hypothesis of the state vector collapse is proposed by looking for deviations from the Boltzmann ... More
BlackfoldsJun 10 2011This is an introduction to the blackfold effective worldvolume theory for the dynamics of black branes, as well as its use as an approximate method for the construction of new black hole solutions. We also explain how the theory is useful for the analysis ... More
Black Hole Production at a TeVFeb 25 2003In this talk I briefly discuss some features of a striking signature of TeV quantum gravity/strings and large extra dimensions: the production of exotic objects such as black holes, and their stringy precursors, the string resonances at large masses which ... More
Black Hole Radiation On and Off the BraneSep 18 2000Sep 26 2000After a brief review of the description of black holes on branes, we examine the evaporation of a small black hole on a brane in a world with large extra dimensions. We show that, contrary to previous claims, most of the energy is radiated into the modes ... More
Black hole entropy as entanglement entropy: a holographic derivationMar 10 2006Apr 26 2006We study the possibility that black hole entropy be identified as entropy of entanglement across the horizon of the vacuum of a quantum field in the presence of the black hole. We argue that a recent proposal for computing entanglement entropy using AdS/CFT ... More
Probing dark energy with future surveysJul 21 2006I review the observational prospects to constrain the equation of state parameter of dark energy and I discuss the potential of future imaging and redshift surveys. Bayesian model selection is used to address the question of the level of accuracy on the ... More
Cosmic Microwave Background Anisotropies: Beyond Standard ParametersOct 05 2004In the first part of this work, I review the theoretical framework of cosmological perturbation theory necessary to understand the generation and evolution of cosmic microwave background (CMB) anisotropies. Using analytical and numerical techniques, in ... More
Optical correlation techniques for the investigation of colloidal systemsJun 06 2013This review aims to provide a simple introduction to the application of optical correlation methods in colloidal science. In particular, I plan to show that full appraisal of the intimate relation between light scattering and microscopy allows designing ... More
X-ray properties of spiral galaxiesNov 01 2002X-ray studies of nearby spiral galaxies with star formation allow us to investigate temperature and spatial distribution of the hot diffuse plasma, and to carry out individual and statistical studies of different classes of discrete sources (low- and ... More