Results for "Lea Marcotulli"

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Compton thick AGN in the NuSTAR eraJan 07 2018We present the 2-100 keV spectral analysis of 30 candidate Compton thick (CT-) active galactic nuclei (AGN) selected in the Swift-BAT 100-month survey. The average redshift of these objects is $\langle z\rangle\sim$0.03 and they all lie within $\sim$500 ... More
Compton-thick AGN in the NuSTAR era III: A systematic study of the torus covering factorDec 21 2018We present the analysis of a sample of 35 candidate Compton thick (CT-) active galactic nuclei (AGNs) selected in the nearby Universe (average redshift <z>~0.03) with the Swift-BAT 100-month survey. All sources have available NuSTAR data, thus allowing ... More
(Anti-)deuteron production and anisotropic flow measured with ALICE at the LHCJun 30 2016The high abundance of (anti-)deuterons in the statistics gathered in Run 1 of the LHC and the excellent performance of the ALICE setup allow for the simultaneous measurement of the elliptic flow and the deuteron production rates with a large transverse ... More
Building a resource for studying translation shiftsJun 22 2006This paper describes an interdisciplinary approach which brings together the fields of corpus linguistics and translation studies. It presents ongoing work on the creation of a corpus resource in which translation shifts are explicitly annotated. Translation ... More
Derivation of the 1d NLS equation from the 3d quantum many-body dynamics of strongly confined bosonsMar 29 2018We consider the dynamics of $N$ interacting bosons initially exhibiting Bose-Einstein condensation. Due to an external trapping potential, the bosons are strongly confined in two spatial directions, with the transverse extension of the trap being of order ... More
Large deviations of Markov chains with multiple time-scalesSep 26 2017Apr 06 2018For Markov processes evolving on multiple time-scales a combination of large component scalings and averaging of rapid fluctuations can lead to useful limits for model approximation. A general approach to proving a law of large numbers to a deterministic ... More
Quasimodular moonshine and arithmetic connectionsOct 30 2018Nov 02 2018We prove the existence of a module for the largest Mathieu group, whose trace functions are weight two quasimodular forms. Restricting to the subgroup fixing a point, we see that the integrality of these functions is equivalent to certain divisibility ... More
Asymptotic genealogy of a critical branching processMar 25 2005Consider a continuous-time binary branching process conditioned to have population size n at some time t, and with a chance p for recording each extinct individual in the process. Within the family tree of this process, we consider the smallest subtree ... More
Chandra and NuSTAR follow-up observations of Swift-BAT selected AGNSep 26 2017Based on current models of the Cosmic X-ray Background (CXB), heavily obscured Active Galactic Nuclei (AGN) are expected to make up ~10% of the peak emission of the CXB and ~20% of the total population of AGN, yet few of these sources have been recorded ... More
$p$-adic properties of certain half-integral weight modular formsSep 01 2015In this paper, we study the parallel cases of Zagier's and Folsom-Ono's grids of weakly holomorphic (resp. weakly holomorphic and mock modular) forms of weights 3/2 and 1/2, investigating their $p$-adic properties under the action of Hecke operators.
Topology and inference for multi-type Yule treesSep 10 2014We introduce two models for multi-type random trees motivated by studies of trait dependence in the evolution of species. Our discrete time model, the multi-type ERM tree, is a generalization of Markov propagation models on a random tree generated by ... More
Scaling limits of spatial compartment models for chemical reaction networksFeb 04 2013Oct 26 2015We study the effects of fast spatial movement of molecules on the dynamics of chemical species in a spatially heterogeneous chemical reaction network using a compartment model. The reaction networks we consider are either single- or multi-scale. When ... More
Some explicit constructions of integral structures in quaternion algebrasJan 14 2008Jan 16 2008Let B be an undefined quaternion algebra over Q. Following the explicit chacterization of some Eichler orders in B given by Hashimoto, we define explicit embeddings of these orders in some local rings of matrices; we describe the two natural inclusions ... More
Categorization in the Wild: Generalizing Cognitive Models to Naturalistic Data across LanguagesFeb 23 2019Categories such as animal or furniture are acquired at an early age and play an important role in processing, organizing, and communicating world knowledge. Categories exist across cultures: they allow to efficiently represent the complexity of the world, ... More
The coalescent point process of multi-type branching treesSep 17 2013We define a multi-type coalescent point process of a general branching process with finitely many types. This multi-type coalescent fully describes the genealogy of the (quasi-stationary) standing population, providing types along ancestral lineages of ... More
A numerical ampleness criterion via Gale dualityApr 27 2015Mar 09 2016This paper is devoted to present a numerical criterion determining when a Weil divisor of a $Q$--factorial complete toric variety admits a positive multiple Cartier divisor which is either numerically effective (nef) or ample. It is obtained as an easy ... More
Fibration and classification of smooth projective toric varieties of low Picard numberJul 02 2015Dec 24 2015In this paper we show that a smooth toric variety $X$ of Picard number $r\leq 3$ always admits a nef primitive collection supported on a hyperplane admitting non-trivial intersection with the cone $\Nef(X)$ of numerically effective divisors. In particular ... More
A Batyrev type classification of $Q$--factorial projective toric varietiesApr 24 2015Sep 13 2017The present paper is devoted to generalizing, inside the class of projective toric varieties, the classification [Batyrev91], performed by Batyrev in 1991 for smooth complete toric varieties, to the singular $Q$--factorial case. Moreover, in the first ... More
Towards an analogue of Ihara's lemma for Shimura curvesFeb 05 2008Jan 04 2010The object of this work is to present the status of art of an open problem: to provide an analogue for Shimura curves of the Ihara's lemma \cite{Ihara73} which holds for modular curves. We will describe our direct result towards the "Problem of Ihara" ... More
Large deviations for multi-scale jump-diffusion processesMar 20 2015Sep 15 2016We obtain large deviation results for a two time-scale model of jump-diffusion processes. The processes on the two time scales are fully inter-dependent, the slow process has small perturbative noise and the fast process is ergodic. Our results extend ... More
Embedding the Picard group inside the class group: the case of $\Q$-factorial complete toric varietiesMar 05 2018Mar 14 2018Let $X$ be a $\Q$-factorial complete toric variety over an algebraic closed field of characteristic $0$. There is a canonical injection of the Picard group ${\rm Pic}(X)$ in the group ${\rm Cl}(X)$ of classes of Weil divisors. These two groups are finitely ... More
A Q-factorial complete toric variety is a quotient of a poly weighted spaceFeb 03 2015Sep 01 2017We prove that every Q-factorial complete toric variety is a finite quotient of a poly weighted space (PWS), as defined in our previous work arXiv:1501.05244. This generalizes the Batyrev-Cox and Conrads description of a Q-factorial complete toric variety ... More
Difffusion Dynamics on the Coexistence Subspace in a Stochastic Evolutionary GameFeb 10 2018Frequency-dependent selection reflects the interaction between different species as they battle for limited resources in their environment. In a stochastic evolutionary game the species relative fitnesses guides the evolutionary dynamics which fluctuate ... More
A Model for Fine-Grained Alignment of Multilingual TextsSep 07 2004While alignment of texts on the sentential level is often seen as being too coarse, and word alignment as being too fine-grained, bi- or multilingual texts which are aligned on a level in-between are a useful resource for many purposes. Starting from ... More
On p-adic Multidimensional Continued FractionsApr 30 2018Multidimensional continued fractions (MCFs) were introduced by Jacobi and Perron in order to generalize the classical continued fractions. In this paper, we propose an introductive fundamental study about MCFs in the field of the $p$--adic numbers $\mathbb ... More
Bayesian binary quantile regression for the analysis of Bachelor-Master transitionNov 21 2015Dec 04 2015The multi-cycle organization of modern university systems stimulates the interest in studying the progression to higher level degree courses during the academic career. In particular, after the achievement of the first level qualification (Bachelor degree), ... More
On the finiteness and periodicity of the $p$--adic Jacobi--Perron algorithmJan 15 2019Multidimensional continued fractions (MCFs) were introduced by Jacobi and Perron in order to obtain periodic representations for algebraic irrationals, as it is for continued fractions and quadratic irrationals. Since continued fractions have been also ... More
MAPLE subroutines for computing Milnor and Tyurina numbers of hypersurface singularities with application to Arnol'd adjacenciesSep 25 2008Jan 25 2012In the present paper MAPLE subroutines computing Milnor and Tyurina numbers of an isolated algebraic hypersurface singularity are presented and described in detail. They represents examples, and perhaps the first ones, of a MAPLE implementation of local ... More
A $\mathbb{Q}$--factorial complete toric variety with Picard number 2 is projectiveApr 15 2015Jul 23 2015This paper is devoted to settle two seemingly still open problems, at least as far as we know, connected with the existence of ample and nef divisors on a $\mathbb{Q}$--factorial complete toric variety. The first problem is about the existence of ample ... More
A Batyrev type classification of $Q$--factorial projective toric varietiesApr 24 2015Jul 31 2015The present paper is devoted to generalizing, inside the class of projective toric varieties, the classification \cite{Batyrev91}, performed by Batyrev in 1991 for smooth complete toric varieties, to the singular $\Q$--factorial case. Moreover, in the ... More
A $\mathbb{Q}$--factorial complete toric variety with Picard number 2 is projectiveApr 15 2015Nov 09 2017This paper is devoted to settle two still open problems, connected with the existence of ample and nef divisors on a Q-factorial complete toric variety. The first problem is about the existence of ample divisors when the Picard number is 2: we give a ... More
Traces of singular values of HauptmodulnJul 16 2014Sep 01 2014In an important paper, Zagier proved that certain half-integral weight modular forms are generating functions for traces of polynomials in the $j$-function. It turns out that Zagier's work makes it possible to algorithmically compute Hilbert class polynomials ... More
GEM Studies for LCTPCJan 30 2009The LCTPC collaboration is developing a time projection chamber (TPC) for a future linear collider. In the ILD concept for an ILC detector a TPC is foreseen as main tracking device. In order to get measurable signals on the anode, the primary electrons, ... More
Computational procedures for weighted projective spacesDec 07 2011This is a pdf print of the homonymous Maple file, freely available at http://www.maplesoft.com/applications/view.aspx?SID=127621, providing procedures which are able to produce the toric data associated with a (polarized) weighted projective space i.e. ... More
A Q-factorial complete toric variety is a quotient of a poly weighted spaceFeb 03 2015Apr 18 2016We prove that every Q-factorial complete toric variety is a finite quotient of a poly weighted space (PWS), as defined in our previous work arXiv:1501.05244. This generalizes the Batyrev-Cox and Conrads description of a Q-factorial complete toric variety ... More
Joint estimation of conditional quantiles in multivariate linear regression models. An application to financial distressAug 03 2018This paper proposes a maximum-likelihood approach to jointly estimate marginal conditional quantiles of multivariate response variables in a linear regression framework. We consider a slight reparameterization of the Multivariate Asymmetric Laplace distribution ... More
$p$-adic properties of certain half-integral weight modular formsSep 01 2015Dec 07 2016In this paper, we study the parallel cases of Zagier's and Folsom-Ono's grids of weakly holomorphic (resp. weakly holomorphic and mock modular) forms of weights 3/2 and 1/2, investigating their $p$-adic properties under the action of Hecke operators.
Z-linear Gale duality and poly weighted spaces (PWS)Jan 21 2015Jan 22 2016The present paper is devoted to discussing Gale duality from the Z-linear algebraic point of view. This allows us to isolate the class of Q-factorial complete toric varieties whose class group is torsion free, here called poly weighted spaces (PWS), as ... More
Derivation of the 1d Gross-Pitaevskii equation from the 3d quantum many-body dynamics of strongly confined bosonsMar 29 2018Oct 24 2018We consider the dynamics of $N$ interacting bosons initially forming a Bose-Einstein condensate. Due to an external trapping potential, the bosons are strongly confined in two dimensions, where the transverse extension of the trap is of order $\varepsilon$. ... More
The coalescent point process of branching treesJan 12 2011Feb 12 2013We define a doubly infinite, monotone labeling of Bienayme-Galton-Watson (BGW) genealogies. The genealogy of the current generation backwards in time is uniquely determined by the coalescent point process $(A_i; i\ge 1)$, where $A_i$ is the coalescence ... More
Ideals with an assigned initial idealJul 24 2008May 07 2010The stratum St(J,<) (the homogeneous stratum Sth(J,<) respectively) of a monomial ideal J in a polynomial ring R is the family of all (homogeneous) ideals of R whose initial ideal with respect to the term order < is J. St(J,<) and Sth(J,<) have a natural ... More
Weighted Projective Spaces from the toric point of view with computational applicationsDec 07 2011Feb 12 2013The purpose of the present paper is threefold. First: giving a treatise on weighted projective spaces by the toric point of view. Second: providing characterizations of fans and polytopes giving weighted projective spaces, with particular focus on a kind ... More
A numerical ampleness criterion via Gale dualityApr 27 2015Nov 16 2016The main object of the present paper is a numerical criterion determining when a Weil divisor of a $\Q$--factorial complete toric variety admits a positive multiple Cartier divisor which is either numerically effective (nef) or ample. It is a consequence ... More
Determination of the position angle of stellar spin axesFeb 13 2014Measuring the stellar position angle provides valuable information on binary stellar formation or stellar spin axis evolution. We aim to develop a method for determining the absolute stellar position angle using spectro-astrometric analysis of high resolution ... More
Manipulation of the dynamics of many-body systems via quantum control methodsMar 12 2010We investigate how dynamical decoupling methods may be used to manipulate the time evolution of quantum many-body systems. These methods consist of sequences of external control operations designed to induce a desired dynamics. The systems considered ... More
Moonshine modules and a question of GriessOct 05 2016Oct 24 2018We consider the situation in which a finite group acts on an infinite-dimensional graded module in such a way that the graded trace functions are weakly holomorphic modular forms. Under a mild hypothesis we completely describe the asymptotic module structure ... More
Randomized Dynamical Decoupling Techniques for Coherent Quantum ControlFeb 21 2006Oct 13 2006The need for strategies able to accurately manipulate quantum dynamics is ubiquitous in quantum control and quantum information processing. We investigate two scenarios where randomized dynamical decoupling techniques become more advantageous with respect ... More
Prosodic Features from Large Corpora of Child-Directed Speech as Predictors of the Age of Acquisition of WordsSep 27 2017The impressive ability of children to acquire language is a widely studied phenomenon, and the factors influencing the pace and patterns of word learning remains a subject of active research. Although many models predicting the age of acquisition of words ... More
Localization and the effects of symmetries in the thermalization properties of one-dimensional quantum systemsJun 03 2010Feb 05 2013We study how the proximity to an integrable point or to localization as one approaches the atomic limit, as well as the mixing of symmetries in the chaotic domain, may affect the onset of thermalization in finite one-dimensional systems. We consider systems ... More
Quantum chaos and thermalization in gapped systemsMar 06 2010Jul 09 2010We investigate the onset of thermalization and quantum chaos in finite one-dimensional gapped systems of hard-core bosons. Integrability in these systems is broken by next-nearest-neighbor repulsive interactions, which also generate a superfluid to insulator ... More
Onset of quantum chaos in one-dimensional bosonic and fermionic systems and its relation to thermalizationOct 15 2009Mar 06 2010By means of full exact diagonalization, we study level statistics and the structure of the eigenvectors of one-dimensional gapless bosonic and fermionic systems across the transition from integrability to quantum chaos. These systems are integrable in ... More
Supercooled fog as a natural laboratory for studying ice formation in cloudsNov 10 2018The ice phase in clouds contributes largely to uncertainties in global climate models partly due to a lack of atmospheric observations. At moderate supercooling ice nucleating particles (INP) and ice particles (IP) are present in small concentrations ... More
A critical branching process model for biodiversityOct 18 2004Motivated as a null model for comparison with data, we study the following model for a phylogenetic tree on $n$ extant species. The origin of the clade is a random time in the past, whose (improper) distribution is uniform on $(0,\infty)$. After that ... More
Advantages of Randomization in Coherent Quantum Dynamical ControlApr 06 2008Control scenarios have been identified where the use of randomized design may substantially improve the performance of dynamical decoupling methods [L. F. Santos and L. Viola, Phys. Rev. Lett. {\bf 97}, 150501 (2006)]. Here, by focusing on the suppression ... More
Enhanced Convergence and Robust Performance of Randomized Dynamical DecouplingFeb 21 2006Oct 13 2006We demonstrate the advantages of randomization in coherent quantum dynamical control. For systems which are either time-varying or require decoupling cycles involving a large number of operations, we find that simple randomized protocols offer superior ... More
Dynamical control of qubit coherence: Random versus deterministic schemesNov 12 2005We revisit the problem of switching off unwanted phase evolution and decoherence in a single two-state quantum system in the light of recent results on random dynamical decoupling methods [L. Viola and E. Knill, Phys. Rev. Lett. {\bf 94}, 060502 (2005)]. ... More
Currencies in resource theoriesMay 03 2016How may we quantify the value of physical resources, such as entangled quantum states, heat baths or lasers? Existing resource theories give us partial answers; however, these rely on idealizations, like perfectly independent copies of states or exact ... More
Compton-thick AGN in the NuSTAR era II: A deep NuSTAR and XMM-Newton view of the candidate Compton thick AGN in NGC 1358Nov 14 2018We present the combined NuSTATR and XMM-Newton 0.6-79 keV spectral analysis of a Seyfert 2 galaxy, NGC 1358, which we selected as a candidate Compton thick (CT-) active galactic nucleus (AGN) on the basis of previous Swift/BAT and Chandra studies. According ... More
General Physical Properties of CGRaBS BlazarsNov 03 2017Nov 07 2017We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 $\gamma$-ray detected ($\gamma$-ray loud) and 191 non $\gamma$-ray detected ($\gamma$-ray ... More
Moonshine modules and a question of GriessOct 05 2016We consider the situation in which a finite group acts on an infinite-dimensional graded module in such a way that the graded-trace functions are weakly holomorphic modular forms. Under some mild hypotheses we completely describe the asymptotic module ... More
Domain wall dynamics in integrable and chaotic spin-1/2 chainsMay 04 2011Jul 13 2011We study the time evolution of correlation functions, spin current, and local magnetization in an isolated spin-1/2 chain initially prepared in a sharp domain wall state. The results are compared with the level of spatial delocalization of the eigenstates ... More
Quantum chaos: an introduction via chains of interacting spins-1/2Jun 28 2011Mar 30 2012We introduce aspects of quantum chaos by analyzing the eigenvalues and the eigenstates of quantum many-body systems. The properties of quantum systems whose classical counterparts are chaotic differ from those whose classical counterparts are not chaotic. ... More
Stochastically-induced bistability in chemical reaction systemsFeb 06 2013May 05 2014We study a stochastic two-species chemical reaction system with two mechanisms. One mechanism consists of chemical interactions which govern the overall drift of species amounts in the system; the other mechanism consists of resampling, branching or splitting ... More
Operational locality in global theoriesJan 12 2017Jan 19 2017Within a global physical theory, a notion of locality allows us to find and justify information-processing primitives, like non-signalling between distant agents. Here we propose exploring the opposite direction: to take agents as the basic building blocks ... More
Extended nonergodic states in disordered many-body quantum systemsOct 06 2016This work supports the existence of extended nonergodic states in the intermediate region between the chaotic (thermal) and the many-body localized phases. These states are identified through an extensive analysis of static and dynamical properties of ... More
New 111-type Semiconductor ReGaSi Follows 14e- RulesMar 09 2017Electron-counting rules were applied to understand the stability, structural preference, and physical properties of metal disilicides. Following predictions made by 14 electron counting rules, the ordered semiconductor ReGaSi, the first ternary phase ... More
Local quenches with global effects in interacting quantum systemsFeb 27 2014Sep 04 2014We study one-dimensional lattices of interacting spins-1/2 and show that the effects of quenching the amplitude of a local magnetic field applied to a single site of the lattice can be comparable to the effects of a global perturbation applied instantaneously ... More
Effects of the interplay between initial state and Hamiltonian on the thermalization of isolated quantum many-body systemsMay 29 2013Oct 14 2013We explore the role of the initial state on the onset of thermalization in isolated quantum many-body systems after a quench. The initial state is an eigenstate of an initial Hamiltonian $\hat{H}_I$ and it evolves according to a different final Hamiltonian ... More
Efficient Hierarchical Markov Random Fields for Object Detection on a Mobile RobotNov 07 2011Object detection and classification using video is necessary for intelligent planning and navigation on a mobile robot. However, current methods can be too slow or not sufficient for distinguishing multiple classes. Techniques that rely on binary (foreground/background) ... More
Quantum interference-induced stability of repulsively bound pairs of excitationsJun 05 2012Sep 22 2012We study the dynamics of two types of pairs of excitations which are bound despite their strong repulsive interaction. One corresponds to doubly occupied sites in one-dimensional Bose-Hubbard systems, the so-called doublons. The other is pairs of neighboring ... More
On the Dipole Approximation with Error EstimatesSep 06 2013May 12 2017The dipole approximation is employed to describe interactions between atoms and radiation. It essentially consists of neglecting the spatial variation of the external field over the atom. Heuristically, this is justified by arguing that the wavelength ... More
On the dipole approximation with error estimatesSep 06 2013Oct 25 2016The dipole approximation is employed to describe interactions between atoms and radiation. It essentially consists of neglecting the spatial variation of the external field over the atom. Heuristically, this is justified by arguing that the wavelength ... More
Dynamics at the Many-Body Localization TransitionJan 22 2015Jul 24 2015The isolated one-dimensional Heisenberg model with static random magnetic fields has become paradigmatic for the analysis of many-body localization. Here, we study the dynamics of this system initially prepared in a highly-excited nonstationary state. ... More
Quench Dynamics of Isolated Many-Body Quantum SystemsOct 18 2013Apr 29 2014We study isolated quantum systems with two-body interactions after a quench. In these systems, the energy shell is a Gaussian of width $\sigma$, and it gives the maximum possible spreading of the energy distribution of the initial states. When the distribution ... More
Structure of eigenstates and quench dynamics at an excited state quantum phase transitionJun 22 2015Nov 25 2015We study the structure of the eigenstates and the dynamics of a system that undergoes an excited state quantum phase transition (ESQPT). The analysis is performed for two-level pairing models characterized by a U(n+1) algebraic structure. They exhibit ... More
Nonexponential fidelity decay in isolated interacting quantum systemsJul 17 2014Sep 29 2014We study isolated finite interacting quantum systems after an instantaneous perturbation and show three scenarios in which the probability for finding the initial state later in time (fidelity) decays nonexponentially, often all the way to saturation. ... More
Large deviations for method-of-quantiles estimators of one-dimensional parametersNov 15 2016Nov 19 2018We consider method-of-quantiles estimators of unknown parameters, namely the analogue of method-of-moments estimators obtained by matching empirical and theoretical quantiles at some probability level lambda in (0,1). The aim is to present large deviation ... More
A microscopic approach to the nonlinear elasticity of compressed emulsionsOct 15 2012Using confocal microscopy, we measure the packing geometry and interdroplet forces as a function of the osmotic pressure in a 3D emulsion system. We find that the nonlinear elastic response of the pressure with density is not a result of the anharmonicity ... More
Estimate of drainage water behaviour in shallow lakesMar 01 2004A theoretical estimate of the explicit time dependence of a drainage water of shallow lakes is presented as an important contribution for understanding the lake dynamics. This information can be obtained from a sum of functions, largely used in fitting ... More
Annotating Predicate-Argument Structure for a Parallel TreebankJul 01 2004We report on a recently initiated project which aims at building a multi-layered parallel treebank of English and German. Particular attention is devoted to a dedicated predicate-argument layer which is used for aligning translationally equivalent sentences ... More
Interplay between interaction and (un)correlated disorder in one-dimensional many-particle systems: delocalization and global entanglementOct 24 2008Dec 27 2009We consider a one-dimensional quantum many-body system and investigate how the interplay between interaction and on-site disorder affects spatial localization and quantum correlations. The hopping amplitude is kept constant. To measure localization, we ... More
Dynamical Manifestations of Quantum Chaos: Correlation Hole and BulgeFeb 14 2017Jan 05 2018A main feature of a chaotic quantum system is a rigid spectrum where the levels do not cross. We discuss how the presence of level repulsion in lattice many-body quantum systems can be detected from the analysis of their time evolution instead of their ... More
Weak and strong typicality in quantum systemsFeb 21 2012Jul 13 2012We study the properties of mixed states obtained from eigenstates of many-body lattice Hamiltonians after tracing out part of the lattice. Two scenarios emerge for generic systems: (i) the diagonal entropy becomes equivalent to the thermodynamic entropy ... More
Bayesian Robust Quantile RegressionMay 18 2016Traditional Bayesian quantile regression relies on the Asymmetric Laplace distribution (ALD) mainly because of its satisfactory empirical and theoretical performances. However, the ALD displays medium tails and it is not suitable for data characterized ... More
Are news important to predict large losses?Oct 25 2014Oct 28 2014In this paper we investigate the impact of news to predict extreme financial returns using high frequency data. We consider several model specifications differing for the dynamic property of the underlying stochastic process as well as for the innovation ... More
Signatures of chaos and thermalization in the dynamics of many-body quantum systemsApr 17 2018We extend the results of two of our papers [Phys. Rev. A 94, 041603R (2016) and Phys. Rev. B 97, 060303R (2018)] that touch upon the intimately connected topics of quantum chaos and thermalization. In the first, we argued that when the initial state of ... More
Genealogy of catalytic branching modelsJun 13 2006Aug 12 2009We consider catalytic branching populations. They consist of a catalyst population evolving according to a critical binary branching process in continuous time with a constant branching rate and a reactant population with a branching rate proportional ... More
Large homogeneous subgraphs in bipartite graphs with forbidden induced subgraphsMar 22 2019For a bipartite graph G, let h(G) be the largest t such that either G or the bipartite complement of G contain K_{t,t}. For a class F of graphs, let h(F)= min {h(G): G\in F}. We say that a bipartite graph H is strongly acyclic if neither H nor its bipartite ... More
DeSSpOt: an instrument for stellar spin orientation determinationAug 14 2012We designed and constructed a special instrument to enable the determination of the stellar's spin orientation. The Differential image rotator for Stellar Spin Orientation, DeSSpOt, allows the simultaneous observations of two anti-parallel orientations ... More
Excited State Quantum Phase Transitions Studied from a Non-Hermitian PerspectiveDec 06 2016A main distinguishing feature of non-Hermitian quantum mechanics is the presence of exceptional points (EPs). They correspond to the coalescence of two energy levels and their respective eigenvectors. Here, we use the Lipkin-Meshkov-Glick (LMG) model ... More
Extended nonergodic states in disordered many-body quantum systemsOct 06 2016Feb 08 2017This work supports the existence of extended nonergodic states in the intermediate region between the chaotic (thermal) and the many-body localized phases. These states are identified through an extensive analysis of static and dynamical properties of ... More
Nonequilibrium quantum dynamics of many-body systemsJun 07 2017Aug 01 2017We review our results for the dynamics of isolated many-body quantum systems described by one-dimensional spin-1/2 models. We explain how the evolution of these systems depends on the initial state and the strength of the perturbation that takes them ... More
Resource theories of knowledgeNov 27 2015How far can we take the resource theoretic approach to explore physics? Resource theories like LOCC, reference frames and quantum thermodynamics have proven a powerful tool to study how agents who are subject to certain constraints can act on physical ... More
Unified Bayesian Conditional Autoregressive Risk Measures using the Skew Exponential Power DistributionFeb 11 2019Conditional Autoregressive Value-at-Risk and Conditional Autoregressive Expectile have become two popular approaches for direct measurement of market risk. Since their introduction several improvements both in the Bayesian and in the classical framework ... More
On the Intermediate Value Theorem over a Valued FieldSep 08 2015The paper proves the intermediate value theorem for polynomials and power series over a valued field with divisible valuation group and infinite residue field. Some further results on the behaviour of the valuation are obtained using Hensel's Lemma.
Large deviations for method-of-quantiles estimators of one-dimensional parametersNov 15 2016We consider method-of-quantiles estimators of unknown parameters, namely the analogue of method-of-moments estimators obtained by matching empirical and theoretical quantiles at some probability level lambda in (0,1). The aim is to present large deviation ... More
An introduction to the spectrum, symmetries, and dynamics of spin-1/2 Heisenberg chainsSep 01 2012May 21 2013Quantum spin chains are prototype quantum many-body systems. They are employed in the description of various complex physical phenomena. The goal of this paper is to provide an introduction to the subject by focusing on the time evolution of a Heisenberg ... More
Stochastic Models for Phylogenetic Trees on Higher-order TaxaFeb 08 2007Aug 28 2007Simple stochastic models for phylogenetic trees on species have been well studied. But much paleontology data concerns time series or trees on higher-order taxa, and any broad picture of relationships between extant groups requires use of higher-order ... More
Curvature-based Gauge-Invariant Perturbation Theory for Gravity: A New ParadigmJan 20 1998A new approach to gravitational gauge-invariant perturbation theory begins from the fourth-order Einstein-Ricci system, a hyperbolic formulation of gravity for arbitrary lapse and shift whose centerpiece is a wave equation for curvature. In the Minkowski ... More
Bayesian inference for CoVaRJun 12 2013Nov 03 2013Recent financial disasters emphasised the need to investigate the consequence associated with the tail co-movements among institutions; episodes of contagion are frequently observed and increase the probability of large losses affecting market participants' ... More