Results for "Ilaria Pascucci"

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An Increase in the Mass of Planetary Systems around Lower-Mass StarsOct 08 2015Oct 20 2015Trends in the planet population with host star mass provide an avenue to constrain planet formation theories. We derive the planet radius distribution function for Kepler stars of different spectral types, sampling a range in host star masses. We find ... More
The Exoplanet Population Observation Simulator. I - The Inner Edges of Planetary SystemsMay 21 2018The Kepler survey provides a statistical census of planetary systems out to the habitable zone. Because most planets are non-transiting, orbital architectures are best estimated using simulated observations of ensemble populations. Here, we introduce ... More
The snow line in viscous disks around low-mass stars: implications for water delivery to terrestrial planets in the habitable zoneMay 13 2015The water ice or snow line is one of the key properties of protoplanetary disks that determines the water content of terrestrial planets in the habitable zone. Its location is determined by the properties of the star, the mass accretion rate through the ... More
Dust Spreading in Debris Discs: Do Small Grains Cling on to Their Birth Environment?Jun 17 2019Debris discs are dusty belts of planetesimals around main-sequence stars, similar to the asteroid and Kuiper belts in our solar system. The planetesimals cannot be observed directly, yet they produce detectable dust in mutual collisions. Observing the ... More
Kinematic links and the co-evolution of MHD winds, jets, and inner disks from a high-resolution optical [OI] surveyNov 15 2018We present a survey of optical [OI] emission at 6300 \AA\ toward 65 TTauri stars at the spectral resolution of $\sim7$ km/s. Past work identified a highly blueshifted velocity component (HVC) tracing microjets, and a less blueshifted low-velocity-component ... More
Evidence for Disk Photoevaporation Driven by the Central StarAug 17 2009The lifetime of isolated protoplanetary disks is thought to be set by the combination of viscous accretion and photoevaporation driven by stellar high-energy photons. Observational evidence for magnetospheric accretion in young sun-like stars is robust. ... More
The Dispersal of Planet-forming discs: Theory confronts ObservationsApr 01 2017Apr 04 2017Discs of gas and dust around Myr-old stars are a by-product of the star formation process and provide the raw material to form planets. Hence, their evolution and dispersal directly impact what type of planets can form and affect the final architecture ... More
The Exoplanet Population Observation Simulator. II -- Population Synthesis in the Era of KeplerMay 21 2019Jul 25 2019The collection of planetary system properties derived from large surveys such as Kepler provides critical constraints on planet formation and evolution. These constraints can only be applied to planet formation models, however, if the observational biases ... More
A New Look at T Tauri Star Forbidden Lines: MHD Driven Winds from the Inner DiskOct 08 2018Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. We report the first high-resolution ($\Delta v\sim$6\kms) analysis of [S II] $\lambda$4068, [O I] $\lambda$5577, ... More
CLIcK: a Continuum and Line fItting Kit for circumstellar disksFeb 11 2019Infrared spectroscopy with medium to high spectral resolution is essential to characterize the gas content of circumstellar disks. Unfortunately, conducting continuum and line radiative transfer of thermochemical disk models is too time-consuming to carry ... More
A stellar-mass-dependent drop in planet occurrence ratesJun 28 2014Jan 11 2015The Kepler Spacecraft has discovered a large number of planets up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperature ... More
An ALMA Survey of faint disks in the Chamaeleon I star-forming region: Why are some Class II disks so faint?Jun 13 2018ALMA surveys of nearby star-forming regions have shown that the dust mass in the disk is correlated with the stellar mass, but with a large scatter. This scatter could indicate either different evolutionary paths of disks or different initial conditions ... More
New millimeter CO observations of the gas-rich debris disks 49 Cet and HD 32297Aug 26 2019Previous observations revealed the existence of CO gas at nearly protoplanetary level in several dust-rich debris disks around young A-type stars. Here we used the ALMA 7m-array to measure $^{13}$CO and C$^{18}$O emission toward two debris disks, 49 Cet ... More
Understanding the origin of the [OI] low-velocity component from T Tauri starsMay 28 2013The formation time, masses, and location of planets are strongly impacted by the physical mechanisms that disperse protoplanetary disks and the timescale over which protoplanetary material is cleared out. Accretion of matter onto the central star, protostellar ... More
FU Orionis: A Binary Star?Nov 27 2003By using the ALFA adaptive optics system at the 3.6m telescope of the Calar Alto Observatory we detected a faint red star in the apparent vicinity of FU Ori, the prototype of the FUor outburst stars. Independent confirmation of the detection is obtained ... More
The Dispersal of Protoplanetary DisksNov 07 2013Protoplanetary disks are the sites of planet formation, and the evolution and eventual dispersal of these disks strongly influences the formation of planetary systems. Disk evolution during the planet-forming epoch is driven by accretion and mass-loss ... More
Far-Ultraviolet H2 Emission from Circumstellar DisksSep 03 2009We analyze the far-ultraviolet (FUV) spectra of 33 classical T Tauri stars (CTTS), including 20 new spectra obtained with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) on the Hubble Space Telescope. Of the sources, 28 are in the ~1 Myr ... More
The Atomic and Molecular Content of Disks Around Very Low-mass Stars and Brown DwarfsNov 05 2013There is growing observational evidence that disk evolution is stellar-mass dependent. Here, we show that these dependencies extend to the atomic and molecular content of disk atmospheres. We analyze a unique dataset of high-resolution Spitzer/IRS spectra ... More
Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass StarsFeb 26 2015Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our Solar System. Here we suggest that the water content of primitive bodies in many planetary ... More
An Obata singular theorem for stratified spacesNov 25 2015Consider a stratified space with a positive Ricci lower bound on the regular set and no cone angle larger than 2$\pi$. For such stratified space we know that the first non-zero eigenvalue of the Laplacian is larger than or equal to the dimension. We prove ... More
PAC-Bayesian bounds for Principal Component Analysis in Hilbert spacesNov 19 2015Based on some new robust estimators of the covariance matrix, we propose stable versions of Principal Component Analysis (PCA) and we qualify it independently of the dimension of the ambient space. We first provide a robust estimator of the orthogonal ... More
Stellar-Mass-Dependent Disk Structure in Coeval Planet-Forming DisksJul 21 2010Previous studies suggest that the planet-forming disks around very-low-mass stars/brown dwarfs may be flatter than those around more massive stars, in contrast to model predictions of larger scale heights for gas-disks around lower-mass stars. We conducted ... More
Double-peaked OI profile: a likely signature of the gaseous ring around KH 15DJun 11 2019KH 15D is a well-known spectroscopic binary because of its unique and dramatic photometric variability. The variability is explained by a circumbinary dust ring but the ring itself was never directly detected. We present a new interpretation of the double-peaked ... More
A Universal Break in the Planet-to-Star Mass-Ratio Function of Kepler MKG starsMar 02 2018We follow the microlensing approach and quantify the occurrence of Kepler exoplanets as a function of planet-to-star mass ratio, q, rather than planet radius or mass. For planets with radii ~1-6 R_earth and periods <100 days, we find that, except for ... More
Emission Lines from the Gas Disk around TW Hydra and the Origin of the Inner HoleApr 25 2011We compare line emission calculated from theoretical disk models with optical to sub-millimeter wavelength observational data of the gas disk surrounding TW Hya and infer the spatial distribution of mass in the gas disk. The model disk that best matches ... More
High-resolution Spectroscopy of [Ne II] Emission from TW HyaJun 26 2007We present high-resolution echelle spectra of [Ne II] 12.81 micron emission from the classical T Tauri star (CTTS) TW Hya obtained with MICHELLE on Gemini North. The line is centered at the stellar radial velocity and has an intrinsic FWHM of 21\pm 4 ... More
Robust Principal Component Analysis in Hilbert spacesJun 01 2016We propose a stable version of Principal Component Analysis (PCA) in the general framework of a separable Hilbert space. It consists in interpreting the projection on the first eigenvectors as a step function applied to the spectrum of the covariance ... More
Kernel Spectral ClusteringJun 21 2016We investigate the question of studying spectral clustering in a Hilbert space where the set of points to cluster are drawn i.i.d. according to an unknown probability distribution whose support is a union of compact connected components. We modify the ... More
Robust dimension-free Gram operator estimatesNov 19 2015In this paper we investigate the question of estimating the Gram operator by a robust estimator from an i.i.d. sample in a separable Hilbert space and we present uniform bounds that hold under weak moment assumptions. The approach consists in first obtaining ... More
Stallings' decomposition theorem for totally disconnected locally compact groupsJun 07 2015Sep 15 2015An analogue of Stallings' decomposition theorem is proved for totally disconnected locally compact groups, i.e., a totally disconnected locally compact group $G$ with more than one end splits either as an HNN-extension $H\ast_K^t$ or non-trivially as ... More
Rational discrete first degree cohomology for totally disconnected locally compact groupsJun 07 2015Mar 15 2017It is well-known that the existence of more than two ends in the sense of J.R. Stallings for a finitely generated discrete group $G$ can be detected on the cohomology group $\mathrm{H}^1(G,R[G])$, where $R$ is either a finite field, the ring of integers ... More
An outline of polar spaces: basics and advancesMar 22 2013This paper is an extended version of a series of lectures on polar spaces given during the workshop and conference 'Groups and Geometries', held at the Indian Statistical Institute in Bangalore in December 2012. The aim of this paper is to give an overview ... More
The center of twisted affine quantum algebras at odd roots of 1Nov 21 2011This paper focuses on twisted affine quantum algebras: an integer form is chosen, and the center of its specialization at odd roots of 1 (of order bigger than 3 in case D_4^{(3)}, bigger than 1 otherwise) is described.
Higgs physics beyond the SM: the non-linear EFT approachMay 04 2015Depending on whether electroweak physics beyond the Standard Model is based on a linear or on a non-linear implementation of the electroweak symmetry breaking, a linear or a chiral Effective Lagrangian is more appropriate. In this talk, the main low-energy ... More
Topological entropy for locally linearly compact vector spaces and field extensionsSep 06 2018Let $\mathbb{K}$ be a discrete field and $(V, \phi)$ a flow over the category of locally linearly compact $\mathbb{K}$-spaces. Here we give the formulas to compute the topological entropy of $(V,\phi)$ subject to the extension or the restriction of scalars. ... More
Robust dimension-free Gram operator estimatesNov 19 2015Mar 31 2017In this paper we investigate the question of estimating the Gram operator by a robust estimator from an i.i.d. sample in a separable Hilbert space and we present uniform bounds that hold under weak moment assumptions. The approach consists in first obtaining ... More
The Neutrino OptionApr 15 2019Apr 27 2019The Neutrino Option is a scenario where the Higgs mass is generated at the same time as neutrino masses in the type-I seesaw model. This framework provides a dynamical origin for the scalar potential of the Standard Model and suggests a new approach to ... More
From the Drinfeld realization to the Drinfeld-Jimbo presentation of affine quantum algebras: the injectivityJul 01 2014In this paper the surjective homomorphism from the Drinfeld realization to the Drinfeld and Jimbo presentation of affine quantum algebras is proved to be injective. A consequence of the arguments used in the paper is the triangular decomposition of the ... More
The R-matrix for (twisted) affine quantum algebrasNov 17 2011In this paper an exponential multiplicative formula for the R-matrix is provided for the twisted affine quantum algebras.
XMM-Newton detection of warm/hot integalactic medium at z~0.01Dec 03 2002May 08 2004We report a ~3 sigma detection of a 21.82 A absorption feature in the direction of the BL Lac MRK 421 which is interpreted as OVII K(alpha) at z~0.01. This corresponds to the redshift of a H absorber in a cosmic void detected by HST along the line of ... More
Signatures of dynamical scalarsMay 18 2015Effective Lagrangians represent an important, model independent tool for studying physics beyond the Standard Model, via its impact on electroweak scale observables. In particular, two different effective descriptions may be appropriate, depending on ... More
Metallicity effects on synthetic Cepheid Period-Luminosity relationsJan 05 1999Apr 08 1999On the basis of new theoretical results useful predictions concerning the Period-Luminosity (PLR) and Period-Luminosity-Color (PLCR) relations both for optical and infrared magnitudes are presented. It is shown that, following the dependence of the instability ... More
The Local Yamabe Constant of Einstein Stratified SpacesNov 28 2014On a compact stratified space (X, g) there exists a metric of constant scalar curvature in the conformal class of g, if the scalar curvature satisfies an integrability condition and if the Yamabe constant of X is strictly smaller than the local Yamabe ... More
Drinfeld Realization of Affine Quantum Algebras: The RelationsJun 25 2014In this paper the structure of the Drinfeld realization $\Udr_q$ of affine quantum algebras (both untwisted and twisted) is described in details, and its defining relations are studied and simplified. As an application, a homomorphism $\psi$ from this ... More
The Neutrino OptionApr 15 2019The Neutrino Option is a scenario where the Higgs mass is generated at the same time as neutrino masses in the type-I seesaw model. This framework provides a dynamical origin for the scalar potential of the Standard Model and suggests a new approach to ... More
The corank of a flow over the category of linearly compact vector spacesMar 11 2018Sep 06 2018For a topological flow $(V,\phi)$ - i.e., $V$ is a linearly compact vector space and $\phi$ a continuous endomorphism of $V$ - we gain a deep understanding of the relationship between $(V,\phi)$ and the Bernoulli shift: a topological flow $(V,\phi)$ is ... More
Robust Principal Component Analysis in Hilbert spacesJun 01 2016Mar 31 2017We propose a stable version of Principal Component Analysis (PCA) in the general framework of a separable Hilbert space. It consists in interpreting the projection on the first eigenvectors as a step function applied to the spectrum of the covariance ... More
The parametrix method for parabolic SPDEsMar 17 2018Jun 01 2018We consider the Cauchy problem for a linear stochastic partial differential equation. By extending the parametrix method for PDEs whose coefficients are only measurable with respect to the time variable, we prove existence, regularity in H\"older classes ... More
Obstacle problem for Arithmetic Asian optionsOct 22 2009We prove existence, regularity and a Feynman-Ka\v{c} representation formula of the strong solution to the free boundary problem arising in the financial problem of the pricing of the American Asian option with arithmetic average.
Nash estimates and upper bounds for non-homogeneous Kolmogorov equationsJun 21 2016We prove a Gaussian upper bound for the fundamental solutions of a class of ultra-parabolic equations in divergence form. The bound is independent on the smoothness of the coefficients and generalizes some classical results by Nash, Aronson and Davies. ... More
A variational method for second order shape derivativesSep 01 2015We consider shape functionals obtained as minima on Sobolev spaces of classical integrals having smooth and convex densities, under mixed Dirichlet-Neumann boundary conditions. We propose a new approach for the computation of the second order shape derivative ... More
Automated Reasoning in Normative Detachment Structures with Ideal ConditionsOct 23 2018Systems of deontic logic suffer either from being too expressive and therefore hard to mechanize, or from being too simple to capture relevant aspects of normative reasoning. In this article we look for a suitable way in between: the automation of a simple ... More
M Stars in the TW Hya Association: Stellar X-rays and Disk DissipationMar 30 2016To investigate the potential connection between the intense X-ray emission from young, low-mass stars and the lifetimes of their circumstellar, planet-forming disks, we have compiled the X-ray luminosities ($L_X$) of M stars in the $\sim$8 Myr-old TW ... More
The Exoplanet Population Observation Simulator. II - Population Synthesis in the Era of KeplerMay 21 2019The collection of planetary system properties derived from large surveys such as Kepler provides critical constraints on planet formation and evolution. These constraints can only be applied to planet formation models, however, if the observational biases ... More
A candidate planetary-mass object with a photoevaporating disk in OrionNov 29 2016In this work, we report the discovery of a candidate planetary-mass object with a photoevaporating protoplanetary disk, Proplyd 133-353, which is near the massive star $\theta^{1}$ Ori C at the center of the Orion Nebula Cluster (ONC). The object was ... More
Evolution of Young Brown Dwarf Disks in the Mid-InfraredJun 21 2004Aug 30 2004We have imaged two bona-fide brown dwarfs with TReCS/GEMINI-S and find mid-infrared excess emission that can be explained by optically thick dust disk models. In the case of the young ($\approx$2Myr) Cha H$\alpha$1 we measure fluxes at 10.4$\mu$m and ... More
Hints for a Turnover at the Snow Line in the Giant Planet Occurrence RateDec 13 2018Jan 29 2019The orbital distribution of giant planets is crucial for understanding how terrestrial planets form and predicting yields of exoplanet surveys. Here, we derive giant planets occurrence rates as a function of orbital period by taking into account the detection ... More
A Super-Solar Metallicity For Stars With Hot Rocky ExoplanetsSep 19 2016The host star metallicity provide a measure of the conditions in protoplanetary disks at the time of planet formation. Using a sample of over 20,000 Kepler stars with spectroscopic metallicities from the LAMOST survey, we explore how the exoplanet population ... More
Observational Constraints on the Stellar Radiation Field Impinging on Transitional Disk AtmospheresSep 18 2012Mid-infrared atomic and ionic line ratios measured in spectra of pre-main sequence stars are sensitive indicators of the hardness of the radiation field impinging on the disk surface. We present a low-resolution Spitzer IRS search for [Ar II] at 6.98 ... More
Do we really know the dust? Systematics and uncertainties of the mid-infrared spectral analysis methodsFeb 03 2009The spectral region around 10 micrometer, showing prominent dust emission bands, is commonly used to derive the chemical composition of protoplanetary dust. Different analysis methods have been proposed for this purpose, but so far, no comparative test ... More
Measuring Organic Molecular Emission in Disks with Low Resolution Spitzer SpectroscopyApr 01 2011We explore the extent to which Spitzer IRS spectra taken at low spectral resolution can be used in quantitative studies of organic molecular emission from disks surrounding low mass young stars. We use Spitzer IRS spectra taken in both the high and low ... More
The Formation of Brown Dwarfs: ObservationsAug 25 2006We review the current state of observational work on the formation of brown dwarfs, focusing on their initial mass function, velocity and spatial distributions at birth, multiplicity, accretion, and circumstellar disks. The available measurements of these ... More
Shape derivatives for minima of integral functionalsJan 13 2014For $\Omega$ varying among open bounded sets in ${\mathbb R} ^n$, we consider shape functionals $J (\Omega)$ defined as the infimum over a Sobolev space of an integral energy of the kind $\int _\Omega[ f (\nabla u) + g (u) ]$, under Dirichlet or Neumann ... More
Exploring the relationship between the magnitudes of seismic eventsJul 20 2015The distribution of the magnitudes of seismic events is generally assumed to be independent on past seismicity. However, by considering events in causal relation, for example mother-daughter, it seems natural to assume that the magnitude of a daughter ... More
Electron-phonon interaction on bundled structures: static and transport propertiesOct 20 2000We study the small-polaron problem of a single electron interacting with the lattice for the Holstein model in the adiabatic limit on a comb lattice, when the electron-phonon interaction acts only on the base sites. The ground state properties can be ... More
Hard Pion Chiral Perturbation Theory for $B\toπ$ and $D\toπ$ FormfactorsJun 07 2010Oct 22 2010We use one-loop Heavy Meson Chiral Perturbation Theory (HMCHPT) as well as a relativistic formulation to calculate the chiral logarithms $m^2_\pi\log{\left(m^2_\pi/\mu^2\right)}$ contributing to the formfactors of the semileptonic $B\rightarrow \pi$ decays ... More
A new global fit of the $L^r_i$ at next-to-next-to-leading order in Chiral Perturbation TheoryMar 30 2011Oct 03 2011A new fit is done to obtain numerical values for the order $p^4$ low-energy-constants $L_i^r$ in Chiral Perturbation Theory. This includes both new data and new calculated observables. We take into account masses, decay constants, $K_{\ell4}$, $\pi\pi$ ... More
Model of human collective decision-making in complex environmentsJul 08 2015Oct 30 2015A continuous-time Markov process is proposed to analyze how a group of humans solves a complex task, consisting in the search of the optimal set of decisions on a fitness landscape. Individuals change their opinions driven by two different forces: (i) ... More
A pixel-based approach to massive lesion detection in X-ray mammographyJul 20 2005A system for the automated detection of massive lesions in mammograms is presented. The approach we adopted is a pixel-based and multi-level one. Each pixel in a mammogram is flagged with the appropriate class membership, e.g. massive lesions or normal ... More
On the characterization of some classes of proximally smooth setsMay 13 2013We provide a complete characterization of closed sets with empty interior and positive reach in $\mathbb{R}^2$. As a consequence, we characterize open bounded domains in $\mathbb{R}^2$ whose high ridge and cut locus agree, and hence $C^1$ planar domains ... More
Finitely generated abelian groups of unitsMay 06 2019Jul 13 2019In 1960 Fuchs posed the problem of characterizing the groups which are the groups of units of commutative rings. In the following years, some partial answers have been given to this question in particular cases. In this paper we address Fuchs' question ... More
Minimum distance of Line Orthogonal Grassmann Codes in even characteristicMay 30 2016Apr 10 2018In this paper we determine the minimum distance of orthogonal line-Grassmann codes for $q$ even. The case $q$ odd was solved in "I. Cardinali, L. Giuzzi, K. Kaipa, A. Pasini, Line Polar Grassmann Codes of Orthogonal Type, J. Pure Applied Algebra." We ... More
Polar Grassmannians and their CodesSep 25 2015We present a concise description of Orthogonal Polar Grassmann Codes and motivate their relevance. We also describe efficient encoding and decoding algorithms for the case of Line Grassmannians and introduce some open problems.
Evidence Against an Edge-On Disk Around the Extrasolar Planet 2MASS 1207 b and a New Thick Cloud Explanation for its Under-LuminosityMar 09 2011(Abridged) Since the discovery of the first directly-imaged, planetary-mass object, 2MASS 1207 b, several works have sought to explain a disparity between its observed temperature and luminosity. Given its known age, distance, and spectral type, 2MASS ... More
Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming RegionOct 14 2018Rings are the most frequently revealed substructure in ALMA dust observations of protoplanetary disks, but their origin is still hotly debated. In this paper, we identify dust substructures in 12 disks and measure their properties to investigate how they ... More
A space-time Trefftz discontinuous Galerkin method for the first-order acoustic wave equationsOct 25 2016We introduce a space-time Trefftz discontinuous Galerkin method for the first-order transient acoustic wave equations in arbitrary space dimensions, extending the scheme of Kretzschmar et al. (2016, IMA J. Numer. Anal., 36, 1599-1635). Test and trial ... More
Calibration setup for ultralow-current transresistance amplifiersOct 17 2016We describe a calibration setup for the transresistance of low-current amplifiers, based on the capacitance-charging method. The calibration can be performed in the current range of typical interest for electron counting experiments. The setup implementation ... More
Implementing the Stochastics Brane Calculus in a Generic Stochastic Abstract MachineNov 17 2012In this paper, we deal with the problem of implementing an abstract machine for a stochastic version of the Brane Calculus. Instead of defining an ad hoc abstract machine, we consider the generic stochastic abstract machine introduced by Lakin, Paulev\'e ... More
Determination of Low Energy Constants and testing Chiral Perturbation Theory at Next to Next to Leading OrderApr 23 2009We present the results of a search for relations between observables that are independent of the Chiral Pertubation Theory (ChPT) Next-to-Next-to-Leading Order (NNLO) Low-Energy Constants (LECs). We have found some relations between observables in $\pi\pi$, ... More
The galactic double-mode Cepheids II. Properties of the generalized phase differencesDec 05 1996By considering the least-squares fits of the double-mode Cepheid light curves discussed in Paper I we defined their properties by their Fourier parameters and generalized phase differences $G_{i,j}$. When plotting the latter quantities as a function of ... More
A Fast Reconstruction Algorithm for Gene NetworksJan 30 2004This paper deals with gene networks whose dynamics is assumed to be generated by a continuous-time, linear, time invariant, finite dimensional system (LTI) at steady state. In particular, we deal with the problem of network reconstruction in the typical ... More
Four Years of Extreme Ultraviolet Observations of Markarian 421. I: Spectral AnalysisAug 01 2000We analyzed the ~950 ks of spectroscopic data accumulated by the Extreme Ultraviolet Explorer (EUVE) satellite between 1994 and 1997 for the BL Lacertae object Markarian 421. The EUV spectrum is well detected in the 70-110 A (112-177 eV) range and can ... More
Finitely generated abelian groups of unitsMay 06 2019In 1960 Fuchs posed the problem of characterizing the groups which are the groups of units of commutative rings. In the following years, some partial answers have been given to this question in particular cases. In this paper we address Fuchs' question ... More
Backtesting Lambda Value at RiskFeb 24 2016Jun 02 2017A new risk measure, the lambda value at risk (Lambda VaR), has been recently proposed from a theoretical point of view as a generalization of the value at risk (VaR). The Lambda VaR appears attractive for its potential ability to solve several problems ... More
On certain submodules of Weyl modules for SO(2n+1,F) with char(F) = 2May 20 2013For $k = 1, 2,...,n-1$ let $V_k = V(\lambda_k)$ be the Weyl module for the special orthogonal group $G = \mathrm{SO}(2n+1,\F)$ with respect to the $k$-th fundamental dominant weight $\lambda_k$ of the root system of type $B_n$ and put $V_n = V(2\lambda_n)$. ... More
Codes and caps from orthogonal GrassmanniansMar 22 2013Jun 28 2013In this paper we investigate linear error correcting codes and projective caps related to the Grassmann embedding $\varepsilon_k^{gr}$ of an orthogonal Grassmannian $\Delta_k$. In particular, we determine some of the parameters of the codes arising from ... More
Dimension-free PAC-Bayesian bounds for matrices, vectors, and linear least squares regressionDec 07 2017Dec 31 2017This paper is focused on dimension-free PAC-Bayesian bounds, under weak polynomial moment assumptions, allowing for heavy tailed sample distributions. It covers the estimation of the mean of a vector or a matrix, with applications to least squares linear ... More
Dimension-free PAC-Bayesian bounds for the estimation of the mean of a random vectorFeb 12 2018In this paper, we present a new estimator of the mean of a random vector, computed by applying some threshold function to the norm. Non asymptotic dimension-free almost sub-Gaussian bounds are proved under weak moment assumptions, using PAC-Bayesian inequalities. ... More
Geometries arising from trilinear forms on low-dimensional vector spacesMar 20 2017Let ${\mathcal G}_k(V)$ be the $k$-Grassmannian of a vector space $V$ with $\dim V=n$. Given a hyperplane $H$ of ${\mathcal G}_k(V)$, we define in [I. Cardinali, L. Giuzzi, A. Pasini, A geometric approach to alternating $k$-linear forms, J. Algebraic ... More
Determination of Low Energy Constants and testing Chiral Perturbation Theory at order $p^6$ (NNLO)Sep 24 2009We present the results of a search for relations between observables that are independent of the Chiral Perturbation Theory (ChPT) Next-to-Next-to-Leading Order (NNLO) Low-Energy Constants (LECs). We have found some relations between observables in $\pi\pi$, ... More
From Risk Measures to Research MeasuresMay 04 2012In order to evaluate the quality of the scientific research, we introduce a new family of scientific performance measures, called Scientific Research Measures (SRM). Our proposal originates from the more recent developments in the theory of risk measures ... More
The galactic double-mode Cepheids I. Frequency analysis of the light curves and comparison with single-mode CepheidsDec 05 1996We submitted the available photometric V data of all the known galactic Double Mode Cepheids (DMCs) to a careful frequency analysis with the aim of detecting in each case the importance of the harmonics and of the cross coupling terms. For each object, ... More
Bernoulli free boundary problem for the infinity LaplacianApr 23 2018We study the interior Bernoulli free boundary for the infinity Laplacian. Our results cover existence, uniqueness, and characterization of solutions (above a threshold representing the "infinity Bernoulli constant"), their regularity, and their relationship ... More
Probing Black Hole Magnetic Fields with QEDMay 25 2018The effect of vacuum birefringence is one of the first predictions of quantum electrodynamics (QED): the presence of a charged Dirac field makes the vacuum birefringent when threaded by magnetic fields. This effect, extremely weak for terrestrial magnetic ... More
Enumerative Coding for Line Polar Grassmannians with applications to codesDec 17 2014Apr 10 2018A $k$-polar Grassmannian is the geometry having as pointset the set of all $k$-dimensional subspaces of a vector space $V$ which are totally isotropic for a given non-degenerate bilinear form $\mu$ defined on $V.$ Hence it can be regarded as a subgeometry ... More
On the Dirichlet and Serrin problems for the inhomogeneous infinity Laplacian in convex domains: Regularity and geometric resultsOct 22 2014May 02 2015Given an open bounded subset $\Omega$ of $\mathbb{R}^n$, which is convex and satisfies an interior sphere condition, we consider the pde $-\Delta_{\infty} u = 1$ in $\Omega$, subject to the homogeneous boundary condition $u = 0$ on $\partial \Omega$. ... More
Minimum distance of Line Orthogonal Grassmann Codes in even characteristicMay 30 2016In this paper we determine the minimum distance of orthogonal line-Grassmann codes for $q$ even. The case $q$ odd was solved in "I. Cardinali, L. Giuzzi, K. Kaipa, A. Pasini, Line Polar Grassmann Codes of Orthogonal Type, J. Pure Applied Algebra." We ... More
Detection through exchange energy of multipartite entanglement in spin ringsJun 20 2014We investigate multipartite entanglement in rings of arbitrary spins with antiferromagnetic interactions between nearest neighbors. In particular, we show that the non-degenerate ground state of rings formed by an even number ($N$) of spins is $N$-partite ... More
Backtesting Lambda Value at RiskFeb 24 2016Jun 12 2016A new risk measure, the lambda value at risk (Lambda VaR), has been recently proposed from a theoretical point of view as a generalization of the value at risk (VaR). The Lambda VaR appears attractive for its potential ability to solve several problems ... More
The interpretations by experimenters of experiments on 'time dilation': 1940-1970 circaAug 04 2000Nov 07 2013Experimental tests on `time dilation' began in 1938 with Ives and Stilwell's work of the transverse Doppler effect due to atoms in inertial flight. Rossi and Hall (1941) inaugurated the era of fast moving elementary particles that dominated the scene ... More