Results for "Alessio Meneghetti"

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Vanishing ideals of binary Hamming spheresFeb 08 2018We show how to efficiently obtain the Algebraic Normal Form of Boolean functions vanishing on Hamming spheres centred at zero. By exploiting the symmetry of the problem we obtain formulas for particular cases, and a computational method to address the ... More
Type-Preserving Matrices and Security of Block CiphersMar 02 2018Nov 30 2018We provide a new property, called Non-Type-Preserving, for a mixing layer which guarantees protection against algebraic attacks based on the imprimitivity of the group generated by the round functions. Our main result is to present necessary and sufficient ... More
Binary linear code weight distribution estimation by random bit stream compressionJun 06 2018A statistical estimation algorithm of the weight distribution of a linear code is shown, based on using its generator matrix as a compression function on random bit strings.
Dynamic modulation of electron correlation by intramolecular modes in charge transfer compoundsNov 17 1999Electron-phonon and electron-electron interactions are in competition in determining the properties of molecular charge transfer conductors and superconductors. The direct influence of phonons on the electron-electron interaction was not before considered ... More
A weight-distribution bound for entropy extractors using linear binary codesMay 12 2014We consider a bound on the bias reduction of a random number generator by processing based on binary linear codes. We introduce a new bound on the total variation distance of the processed output based on the weight distribution of the code generated ... More
Code generator matrices as entropy extractorsFeb 05 2015We show the connection between the Walsh spectrum of the output of a binary random number generator (RNG) and the bias of individual bits, and use this to show how previously known bounds on the performance of linear binary codes as entropy extractors ... More
On optimal nonlinear systematic codesJun 10 2015Feb 11 2016Most bounds on the size of codes hold for any code, whether linear or not. Notably, the Griesmer bound holds only in the linear case and so optimal linear codes are not necessarily optimal codes. In this paper we identify code parameters $(q,d,k)$, namely ... More
Code generator matrices as RNG conditionersFeb 05 2015Mar 02 2017We quantify precisely the distribution of the output of a binary random number generator (RNG) after conditioning with a binary linear code generator matrix by showing the connection between the Walsh spectrum of the resulting random variable and the ... More
Two-tier blockchain timestamped notarization with incremental securityFeb 08 2019Digital notarization is one of the most promising services offered by modern blockchain-based solutions. We present a digital notary design with incremental security and cost reduced with respect to current solutions. A client of the service receives ... More
On the Griesmer bound for nonlinear codesJan 18 2015Most bounds on the size of codes hold for any code, whether linear or nonlinear. Notably, the Griesmer bound, holds only in the linear case. In this paper we characterize a family of systematic nonlinear codes for which the Griesmer bound holds. Moreover, ... More
A survey on efficient parallelization of blockchain-based smart contractsFeb 08 2019The main problem faced by smart contract platforms is the amount of time and computational power required to reach consensus. In a classical blockchain model, each operation is in fact performed by each node, both to update the status and to validate ... More
On a conjecture of Wilf about the Frobenius numberAug 22 2014May 20 2015Given coprime positive integers $a_1 < ...< a_d$, the Frobenius number $F$ is the largest integer which is not representable as a non-negative integer combination of the $a_i$. Let $g$ denote the number of all non-representable positive integers: Wilf ... More
X-ray morphological estimators for galaxy clustersNov 29 2012Jan 28 2013The classification of galaxy clusters according to their X-ray appearance is a powerful tool to discriminate between regular clusters (associated to relaxed objects) and disturbed ones (linked to dynamically active systems). The compilation of the two ... More
cD galaxy contribution to the strong lensing cross sections of galaxy clustersFeb 28 2003Aug 06 2003We perform ray-tracing simulations evaluating the effect of a cD galaxy on the strong lensing properties of five galaxy cluster halos obtained from N-body simulations. The cD galaxy is modelled using both axially symmetric and elliptical models and assuming ... More
Freudenthal Duality in Gravity: from Groups of Type E7 to Pre-Homogeneous SpacesSep 03 2015Sep 29 2015Freudenthal duality can be defined as an anti-involutive, non-linear map acting on symplectic spaces. It was introduced in four-dimensional Maxwell-Einstein theories coupled to a non-linear sigma model of scalar fields. In this short review, I will consider ... More
Finite generation of adjoint rings after Lazic: an introductionJun 26 2010An introduction to all the key ideas of Lazic's proof of the theorem on the finite generation of adjoint rings.
The shear modulus of metastable amorphous solids with strong central and bond-bending interactionsJul 23 2008Feb 17 2009We derive expressions for the shear modulus of deeply-quenched, glassy solids, in terms of a Cauchy-Born free energy expansion around a rigid (quenched) reference state, following the approach due to Alexander [Alexander, Phys. Rep. 296, 1998]. Continuum-limit ... More
A characterization of the Arf property for quadratic quotients of the Rees algebraJun 12 2018Dec 06 2018We provide a characterization of the Arf property in both the numerical duplication of a numerical semigroup and in a member of a family of quotients of the Rees algebra studied in arXiv:1403.4200 [math.AC]
Asymptotically Moebius maps and rigidity for the hyperbolic planeJun 25 2019Let $S$ be a rank-one symmetric space of non-compact type and let $X$ be a $\text{CAT}(-1)$ space. A well-known result by Bourdon states that if a topological embedding $\varphi: \partial_\infty S \rightarrow \partial_\infty X$ respects cross ratios, ... More
Inference for Additive Models in the Presence of Possibly Infinite Dimensional Nuisance ParametersNov 07 2016Aug 20 2018A framework for estimation and hypothesis testing of functional restrictions against general alternatives is proposed. The parameter space is a reproducing kernel Hilbert space (RKHS). The null hypothesis does not necessarily define a parametric model. ... More
Blowup algebras of rational normal scrollsOct 13 2016Sep 09 2018We determine the equations of the blowup of $\mathbb{P}^n$ along a $d$-fold rational normal scroll $S$, and we prove that the Rees ring and special fiber ring of $S \subseteq \mathbb{P}^n$ are Koszul algebras.
Asymptotic Structure and Bondi-Metzner-Sachs group in General RelativityJan 05 2018Jan 20 2019In this work the asymptotic structure of space-time and the main properties of the Bondi-Metzner-Sachs (BMS) group, which is the asymptotic symmetry group of asymptotically flat space-times, are analysed. Every chapter, except the fourth, begins with ... More
Joint functional calculi and a sharp multiplier theorem for the Kohn Laplacian on spheresJan 18 2016Let $\Box_b$ be the Kohn Laplacian acting on $(0,j)$-forms on the unit sphere in $\mathbb{C}^n$. In a recent paper of Casarino, Cowling, Sikora and the author, a spectral multiplier theorem of Mihlin--H\"ormander type for $\Box_b$ is proved in the case ... More
Rigidity at infinity for the Borel function of the tetrahedral reflection latticeJun 06 2019Let $\Gamma$ be a non-uniform lattice of $PSL(2,\mathbb{C})$. To every representation $\rho:\Gamma \rightarrow PSL(n,\mathbb{C})$ it is possible to associate a numerical invariant $\beta_n(\rho)$, called Borel invariant, which is constant on the $PSL(n,\mathbb{C})$-conjugancy ... More
On the type of an almost Gorenstein monomial curveJul 21 2015Aug 22 2016We prove that the Cohen-Macaulay type of an almost Gorenstein monomial curve $\mathcal C \subseteq \mathbb{A}^4$ is at most $3$, and make some considerations on the general case.
The first elements of the quotient of a numerical semigroup by a positive integerDec 27 2013Apr 11 2015Given three pairwise coprime positive integers $a_1,a_2,a_3 \in \mathbb{Z}^+$ we show the existence of a relation between the sets of the first elements of the three quotients $\frac{\langle a_i,a_j \rangle}{a_k}$ that can be made for every $\{i.j,k\}=\{1,2,3\}$. ... More
Numerical semigroups with large embedding dimension satisfy Wilf's conjectureNov 08 2011Dec 17 2012We give an affirmative answer to Wilf's conjecture for numerical semigroups satisfying 2 \nu \geq m, where \nu and m are respectively the embedding dimension and the multiplicity of a semigroup. The conjecture is also proved when m \leq 8 and when the ... More
Greedy algorithms for predictionFeb 05 2016In many prediction problems, it is not uncommon that the number of variables used to construct a forecast is of the same order of magnitude as the sample size, if not larger. We then face the problem of constructing a prediction in the presence of potentially ... More
Minimal relations and the Diophantine Frobenius Problem in embedding dimension threeAug 22 2016Aug 24 2016This paper provides a formula for the minimal relations and the Frobenius number of a numerical semigroup minimally generated by three pairwise coprime positive integers.
Singularly perturbed Neumann problems with potentialsOct 08 2003We study the existence of concentrating solutions of a singularly perturbed Neumann problems with two potentials.
Algebras of differential operators on Lie groups and spectral multipliersJul 07 2010This thesis is devoted to the study of joint spectral multipliers for a system of pairwise commuting, self-adjoint left-invariant differential operators L_1,...,L_n on a connected Lie group G. Under the assumption that the algebra generated by L_1,...,L_n ... More
Spectral multipliers on Heisenberg-Reiter and related groupsDec 04 2012Let $L$ be a homogeneous sublaplacian on a 2-step stratified Lie group $G$ of topological dimension $d$ and homogeneous dimension $Q$. By a theorem due to Christ and to Mauceri and Meda, an operator of the form $F(L)$ is bounded on $L^p$ for $1 < p < ... More
Borel invariant for Zimmer cocycles of 3-manifold groupsJul 04 2019Let $\Gamma$ be a non-uniform lattice of $\text{PSL}(2,\mathbb{C})$. Given any representation $\rho:\Gamma \rightarrow \text{PSL}(n,\mathbb{C})$ we can define a numerical invariant $\beta_n(\rho)$, called Borel invariant, which remains constant along ... More
Generators of a fraction of a numerical semigroupFeb 20 2014May 30 2015Given a numerical semigroup $S$ and a positive integer $d$, the fraction $\frac{S}{d}=\{ x \in \mathbb{N} \ | \ dx \in S\}$ is again a numerical semigroup. In this paper we determine a generating set for $\frac{S}{d}$ in terms of the minimal generators ... More
On the least positive solution to a proportionally modular Diophantine inequalitDec 18 2013Feb 03 2014Given three positive integers $a,b,c$, a proportionally modular Diophantine inequality is an expression of the form $ax \mod{b} \le cx$. Our aim is to give a recursive formula for the least solution to such an inequality. We then use the formula to derive ... More
The symmetric signatureJun 10 2016This is the author's Ph.D. thesis. We introduce two related invariants for local (and standard graded) rings called differential and syzygy symmetric signature. These are defined by looking at the maximal free splitting of the module of K\"ahler differentials ... More
The LHCb UpgradeOct 01 2013The LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux involving beauty and charm quarks produced at the LHC. The operation and the results obtained from the data collected ... More
Weber's formula for the bitangents of a smooth plane quarticDec 06 2016In a section of his 1876 treatise Theorie der Abel'schen Functionen vom Geschlecht 3 Weber proved a formula that expresses the bitangents of a non-singular plane quartic in terms of Riemann theta constants (Thetanullwerte). The present note is devoted ... More
Blowup algebras of rational normal scrollsOct 13 2016We investigate the algebraic relations among the minors of a $2 \times c$ matrix with $d$ catalecticant blocks, which define a $d$-fold rational normal scroll $\mathcal{S}\subseteq \mathbb{P}^{c+d- 1}$. We determine the equations of the blowup of $\mathbb{P}^{c+d-1}$ ... More
On integers which are representable as sums of large squaresAug 06 2014Apr 11 2015We prove that the greatest positive integer that is not expressible as a linear combination with integer coefficients of elements of the set $\{n^2,(n+1)^2,\ldots \}$ is asymptotically $O(n^2)$, verifying thus a conjecture of Dutch and Rickett. Furthermore ... More
Analysis of joint spectral multipliers on Lie groups of polynomial growthOct 06 2010Dec 19 2010We study the problem of L^p-boundedness (1 < p < \infty) of operators of the form m(L_1,...,L_n) for a commuting system of self-adjoint left-invariant differential operators L_1,...,L_n on a Lie group G of polynomial growth, which generate an algebra ... More
Consecutive cancellations in Tor modules over local ringsMay 17 2016Let $M, N$ be finite modules over a Noetherian local ring $R$, and let $G$ be the associated graded ring of $R$. We show that the bigraded Hilbert series of $gr(Tor^R(M,N))$ is obtained from that of $Tor^G(gr(M),gr(N))$ by negative consecutive cancellations, ... More
Oscillating solutions for prescribed mean curvature equations: Euclidean and Lorentz-Minkowski casesSep 20 2017Feb 25 2018This paper deals with the prescribed mean curvature equations both in the Euclidean case and in the Lorentz-Minkowski case in presence of a nonlinearity $g$ such that $g'(0)>0$. We show the existence of oscillating solutions, namely with an unbounded ... More
A characterization of the Arf property for quadratic quotients of the Rees algebraJun 12 2018May 13 2019We provide a characterization of the Arf property in both the numerical duplication of a numerical semigroup and in a member of a family of quotients of the Rees algebra studied in arXiv:1403.4200 [math.AC]
Generalized uncertainty inequalitiesApr 05 2008In this paper, Heisenberg-Pauli-Weyl-type uncertainty inequalities are obtained for a pair of positive-self adjoint operators on a Hilbert space, whose spectral projectors satisfy a ``balance condition'' involving certain operator norms. This result is ... More
On first attempts to reconcile quantum principles with gravitySep 26 2013In his 1916's first paper on gravitational waves Einstein began to speculate on interactions between the principles of the old quantum theory and his theory of gravitation. With this contribution Einstein has stimulated a lot of similar speculations, ... More
9 generators of the skein space of the 3-torusMar 31 2016We show that the skein vector space of the 3-torus is finitely generated. We show that it is generated by 9 elements: the empty set, some simple closed curves representing the non null elements of the first homology group with coefficients in \Z_2, and ... More
Shadows and quantum invariantsOct 15 2016This is a PhD thesis about low dimensional topology, in particular knot thory in 3-manifolds also different from the 3-sphere, topological applications of quantum invariants, and Turaev's shadows. There is an introduction and a survey for these topics. ... More
A Real-Time, GPU-Based, Non-Imaging Back-End for Radio TelescopesJan 31 2014Since the discovery of RRATs, interest in single pulse radio searches has increased dramatically. Due to the large data volumes generated by these searches, especially in planned surveys for future radio telescopes, such searches have to be conducted ... More
Feedback control in quantum optics: an overview of experimental breakthroughs and areas of applicationOct 15 2012Nov 22 2012We present a broad summary of research involving the application of quantum feedback control techniques to optical set-ups, from the early enhancement of optical amplitude squeezing to the recent stabilisation of photon number states in a microwave cavity, ... More
Schrodinger equation with critical Sobolev exponentJan 22 2004In this paper we study the existence of solutions and their concentration phenomena of a singularly perturbed semilinear Schrodinger equation with the presence of the critical Sobolev exponent.
A true real-time success story: the case of collecting beauty-ful data at the LHCb experimentJun 22 2018Jun 25 2018The LHCb experiment at CERN is currently completing its first big data taking campaign at the LHC started in 2009. It has been collecting data at more than 2.5 times its nominal design luminosity value and with a global efficiency of ~92%. Even more striking, ... More
Rigidity at infinity for lattices in rank-one Lie groupsNov 03 2017Jun 21 2018Let $\Gamma$ be a non-uniform lattice in $PU(p,1)$ without torsion and with $p\geq2 $. We introduce the notion of volume for a representation $\rho:\Gamma \rightarrow PU(m,1)$ where $m \geq p$. We use this notion to generalize the Mostow--Prasad rigidity ... More
s-Hankel hypermatrices and 2 x 2 determinantal idealsOct 16 2012Jun 11 2016We introduce the concept of s-Hankel hypermatrix, which generalizes both Hankel matrices and generic hypermatrices. We study two determinantal ideals associated to an s-Hankel hypermatrix: the ideal I<s,t> generated by certain 2 x 2 slice minors, and ... More
Patterns on the numerical duplication by their admissibility degreeJan 29 2019We develop the theory of patterns on numerical semigroups in terms of the admissibility degree. We prove that the Arf pattern induces every strongly admissible pattern, and determine all patterns equivalent to the Arf pattern. We study patterns on the ... More
On the multiplicity of tangent cones of monomial curvesNov 29 2017Sep 09 2018Let $\Lambda$ be a numerical semigroup, $\mathcal{C}\subseteq \mathbb{A}^n$ the monomial curve singularity associated to $\Lambda$, and $\mathcal{T}$ its tangent cone. In this paper we provide a sharp upper bound for the least positive integer in $\Lambda$ ... More
The Tait conjecture in g(S^1xS^2)Feb 09 2016The Tait conjecture states that alternating reduced diagrams of links in S^3 have the minimal number of crossings. It has been proved in 1987 by M. Thistlethwaite, L. Kauffman and K. Murasugi studying the Jones polynomial. The author proved an analogous ... More
Charge Orbits and Moduli Spaces of Black Hole AttractorsDec 16 2010Dec 28 2010We report on the theory of "large" U-duality charge orbits and related "moduli spaces" of extremal black hole attractors in N = 2, d = 4 Maxwell-Einstein supergravity theories with symmetric scalar manifolds, as well as in N > 3-extended, d = 4 supergravities. ... More
Spin-Bits and N=4 SYMApr 24 2006May 04 2006We briefly review the spin-bit formalism, describing the non-planar dynamics of the $\mathcal{N}=4,d=4$ Super Yang-Mills SU(N) gauge theory. After considering its foundations, we apply such a formalism to the $su(2)$ sector of purely scalar operators. ... More
On a Coarse-Graining Concept in Colloidal Physics with Application to Fluid and Arrested Colloidal Suspensions in Shearing FieldsApr 13 2010We poorly understand the macroscopic properties of complex fluids and of amorphous bodies in general. This is mainly due to the interplay between phenomena at different levels and length-scales. In particular, it is not necessarily true that the microscopic ... More
Simple model for the static structure and the mean coordination of amorphous solidsMay 07 2009We propose a simple route to evaluate the static structure, in terms of average coordination, of completely disordered solids with spherical constituents, from ca. 55% volume fraction up to random close packing, in the absence of structural heterogeneities. ... More
Inference for Additive Models in the Presence of Infinite Dimensional Nuisance ParametersNov 07 2016A framework for hypothesis testing of functional restrictions against general alternatives is proposed. The parameter space is a reproducing kernel Hilbert space. The null the hypothesis does not necessarily define a parametric model. The tests allow ... More
Spectral theory for commutative algebras of differential operators on Lie groupsJul 29 2010The joint spectral theory of a system of pairwise commuting self-adjoint left-invariant differential operators L_1,...,L_n on a connected Lie group G is studied, under the hypothesis that the algebra generated by them contains a "weighted subcoercive ... More
Torsional instability and sensitivity analysis in a suspension bridge model related to the Melan equationJul 19 2018Inspired by the Melan equation we propose a model for suspension bridges with two cables linked to a deck, through inextensible hangers. We write the energy of the system and we derive from variational principles two nonlinear and nonlocal hyperbolic ... More
Detecting multimode entanglement by symplectic uncertainty relationsAug 31 2005Aug 17 2006A hierarchy of multimode uncertainty relations on the second moments of n pairs of canonical operators is derived in terms of quantities invariant under linear canonical (i.e. symplectic) transformations. Conditions for the separability of multimode continuous ... More
Ground states for a system of nonlinear Schrodinger equations with three waves interactionOct 19 2009We consider a system of nonlinear Schrodinger equations with three waves interaction studying the existence of ground state solutions. In particular, we find a vector ground state, namely a ground state with the three components all different from zero. ... More
Weak Convergence of Laws on R^{K} with Common MarginalsJun 19 2006We present a result on topologically equivalent integral metrics (Rachev, 1991, Muller, 1997) that metrize weak convergence of laws with common marginals. This result is relevant for applications, as shown in a few simple examples.
Stationary layered solutions for a system of Allen-Cahn type equationsNov 25 2012Dec 03 2012We consider a class of semilinear elliptic system of the form $-\Delta u(x,y)+\nabla W(u(x,y))=0,\quad (x,y)\in\R^{2}$ where $W:\R^{2}\to\R$ is a double well non negative symmetric potential. We show, via variational methods, that if the set of solutions ... More
The $ω$-Borel invariant for representations into $SL(n,\mathbb{C}_ω)$Sep 22 2017Let $\Gamma$ be the fundamental group of a complete hyperbolic $3$-manifold $M$ with toric cusps. We define the $\omega$-Borel invariant $\beta_n^\omega(\rho_\omega)$ associated to a representation $\rho_\omega: \Gamma \rightarrow SL(n,\mathbb{C}_\omega)$, ... More
Arc StatisticsMar 14 2013The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is compatible with ... More
Strong lensing in the MareNostrum Universe: biases in the cluster lens populationMar 23 2010Strong lensing is one of the most direct probes of the mass distribution in the inner regions of galaxy clusters. It can be used to constrain the density profiles and to measure the mass of the lenses. Moreover, the abundance of strong lensing events ... More
The effects of ellipticity and substructure on estimates of cluster density profiles based on lensing and kinematicsSep 13 2005Jul 18 2007We address the question of how well the density profile of galaxy clusters can be determined by combining strong lensing and velocity dispersion data. We use cosmological dark matter simulations of clusters to test the reliability of the method, producing ... More
On the Discrepancy between Theoretical and X-Ray Concentration-Mass Relations for Galaxy ClustersJan 30 2013Sep 16 2013[Abridged] In the past 15 years, the concentration-mass relation has been investigated diffusely in theoretical studies. On the other hand, only recently has this relation been derived from X-ray observations. When that happened, the results caused a ... More
Application and Simulation of Computerized Adaptive Tests Through the Package catsimJul 10 2017Jul 20 2018This paper presents catsim, the first package written in the Python language specialized in computerized adaptive tests and the logistical models of Item Response Theory. catsim provides functions for generating item and examinee parameters, simulating ... More
Accuracy of photometric redshifts for future weak lensing surveys from spaceJan 17 2012Mar 21 2012Photometric redshifts are a key tool to extract as much information as possible from planned cosmic shear experiments. In this work we aim to test the performances that can be achieved with observations in the near-infrared from space and in the optical ... More
Cluster galaxies: contribution to the arc statisticsAug 30 2000We present the results of a set of numerical simulations aiming at evaluating the effects of cluster galaxies on the arc statistics. At this goal we use nine different galaxy clusters obtained from N-body simulations. We mimic the presence of a population ... More
An optimal filter for the detection of galaxy clusters through weak lensingDec 22 2004We construct a linear filter optimised for detecting dark-matter halos in weak-lensing data. The filter assumes a mean radial profile of the halo shear pattern and modifies that shape by the noise power spectrum. Aiming at separating dark-matter halos ... More
Gravitational lensing of the CMB by galaxy clustersAug 03 2004Aug 03 2004We adapt a non-linear filter proposed by Hu 2001 for detecting lensing of the CMB by large-scale structures to recover surface-density profiles of galaxy clusters from their localised, weak gravitational lensing effect on CMB fields. Shifting the band-pass ... More
Mass Distributions of HST Galaxy Clusters from Gravitational ArcsNov 10 2005Although N-body simulations of cosmic structure formation suggest that dark matter halos have density profiles shallower than isothermal at small radii and steeper at large radii, whether observed galaxy clusters follow this profile is still ambiguous. ... More
Effects of the halo concentration distribution on strong-lensing optical depth and X-ray emissionMay 22 2007Sep 24 2007We use simulated merger trees of galaxy-cluster halos to study the effect of the halo concentration distribution on strong lensing and X-ray emission. Its log-normal shape typically found in simulations favors outliers with high concentration. Since, ... More
Searching dark-matter halos in the GaBoDS surveyJul 12 2006We apply the linear filter for the weak-lensing signal of dark-matter halos developed in Maturi et al. (2005) to the cosmic-shear data extracted from the Garching-Bonn-Deep-Survey (GaBoDS). We wish to search for dark-matter halos through weak-lensing ... More
Exceptional Lie Algebras at the very Foundations of Space and TimeJun 29 2015While describing the results of our recent work on exceptional Lie and Jordan algebras, so tightly intertwined in their connection with elementary particles, we will try to stimulate a critical discussion on the nature of spacetime and indicate how these ... More
Quantum Harmonic Black Holes (Proceeding of the Karl Schwarzschild Meeting 2013)Oct 23 2013Inspired by the recent conjecture that black holes are condensates of gravitons, we investigate a simple model for the black hole degrees of freedom that is consistent both from the point of view of Quantum mechanics and of General Relativity. Since the ... More
The Fermi-polaron in two dimensions: Importance of the two-body bound stateMay 17 2011Sep 13 2011We investigate a single impurity interacting with a free two-dimensional atomic Fermi gas. The interaction between the impurity and the gas is characterized by an arbitrary attractive short-range potential, which, in two dimensions, always admits a two-particle ... More
Longitudinal quantile regression in presence of informative drop-out through longitudinal-survival joint modelingApr 04 2014We propose a joint model for a time-to-event outcome and a quantile of a continuous response repeatedly measured over time. The quantile and survival processes are associated via shared latent and manifest variables. Our joint model provides a flexible ... More
On Some Scalar Field Equations with Competing CoefficientsAug 05 2015Oct 20 2015This paper deals with semilinear elliptic problems of the type \[ \left\{ \begin{array}{ll} -\Delta u+\alpha(x)u= \beta (x)|u|^{p-1}u \quad \hbox{in }\mathbb{R}^N, u(x)>0\quad\hbox{in } \mathbb{R}^N, \qquad u \in H^1(\mathbb{R}^N), \end{array} \right. ... More
Ab-initio description of hole localization and Zhang-Rice singlets in one-dimensional doped cupratesMar 04 2008We present the first ab-initio band-theory-based description of spin-compensated polarons (known as Zhang-Rice singlets) in a hole-doped cuprate, specifically one-dimensional Ca_{2+x} Y_{2-x} Cu_5 O_10. Zhang-Rice singlets are many-particle configurations ... More
A self-interaction corrected pseudopotential scheme for magnetic and strongly-correlated systemsMar 03 2003Local-spin-density functional calculations may be affected by severe errors when applied to the study of magnetic and strongly-correlated materials. Some of these faults can be traced back to the presence of the spurious self-interaction in the density ... More
Dual virtual element method for discrete fractures networksOct 10 2016Discrete fracture networks is a key ingredient in the simulation of physical processes which involve fluid flow in the underground, when the surrounding rock matrix is considered impervious. In this paper we present two different models to compute the ... More
Interactions between Knowledge and Time in a First-Order Logic for Multi-Agent Systems: Completeness ResultsJan 23 2014We investigate a class of first-order temporal-epistemic logics for reasoning about multi-agent systems. We encode typical properties of systems including perfect recall, synchronicity, no learning, and having a unique initial state in terms of variants ... More
Deciding Hedged BisimilarityNov 10 2016The spi-calculus is a formal model for the design and analysis of cryptographic protocols: many security properties, such as authentication and strong confidentiality, can be reduced to the verification of behavioural equivalences between spi processes. ... More
Standard Model False Vacuum Inflation: Correlating the Tensor-to-Scalar Ratio to the Top Quark and Higgs Boson massesDec 22 2011May 03 2012For a narrow band of values of the top quark and Higgs boson masses, the Standard Model Higgs potential develops a false minimum at energies of about $10^{16}$ GeV, where primordial Inflation could have started in a cold metastable state. A graceful exit ... More
The Higgs mass range from Standard Model false vacuum Inflation in scalar-tensor gravityDec 12 2011Mar 05 2012If the Standard Model is valid up to very high energies it is known that the Higgs potential can develop a local minimum at field values around $10^{15}-10^{17}$ GeV, for a narrow band of values of the top quark and Higgs masses. We show that in a scalar-tensor ... More
Random Access in DVB-RCS2: Design and Dynamic Control for Congestion AvoidanceJan 26 2015In the current DVB generation, satellite terminals are expected to be interactive and capable of transmission in the return channel with satisfying quality. Considering the bursty nature of their traffic and the long propagation delay, the use of a random ... More
Interfaces and wetting transition on the half plane. Exact results from field theoryMar 08 2013We consider the scaling limit of a generic ferromagnetic system with a continuous phase transition, on the half plane with boundary conditions leading to the equilibrium of two different phases below criticality. We use general properties of low energy ... More
Phase separation in a wedge. Exact resultsMar 05 2014The exact theory of phase separation in a two-dimensional wedge is derived from the properties of the order parameter and boundary condition changing operators in field theory. For a shallow wedge we determine the passage probability for an interface ... More
Exact theory of intermediate phases in two dimensionsOct 16 2013We show how field theory yields the exact description of intermediate phases in the scaling limit of two-dimensional statistical systems at a first order phase transition point. The ability of a third phase to form an intermediate wetting layer or only ... More
Pseudoscalar mesons in a finite cubic volume with twisted boundary conditionsJul 04 2016We study the effects of a finite cubic volume with twisted boundary conditions on pseudoscalar mesons. We first apply chiral perturbation theory in the p-regime and calculate the corrections for masses, decay constants, pseudoscalar coupling constants ... More
A three-scale model of spatio-temporal burstingOct 29 2015Jul 10 2016We study spatio-temporal bursting in a three-scale reaction diffusion equation organized by the winged cusp singularity. For large time-scale separation the model exhibits traveling bursts, whereas for large space-scale separation the model exhibits standing ... More
Thermally Activated Fracture of Porous MediaMay 24 2016The lifetime of a porous media, submitted to a constant subcritical stress, is studied by means of a numerical model. This model is based on a spring network where the porosity is represented by missing springs. The dynamics is produced adding thermal ... More