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Results for "Claudio Canella"

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Store-to-Leak Forwarding: Leaking Data on Meltdown-resistant CPUsMay 14 2019Meltdown and Spectre exploit microarchitectural changes the CPU makes during transient out-of-order execution. Using side-channel techniques, these attacks enable leaking arbitrary data from memory. As state-of-the-art software mitigations for Meltdown ... More
ConTExT: Leakage-Free Transient ExecutionMay 22 2019Out-of-order execution and speculative execution are among the biggest contributors to performance and efficiency of modern processors. However, they are inconsiderate, leaking secret data during the transient execution of instructions. Many solutions ... More
A Systematic Evaluation of Transient Execution Attacks and DefensesNov 13 2018Feb 20 2019Modern CPU optimizations such as branch prediction and out-of-order execution are crucial for performance. Recent research on transient execution attacks including Spectre and Meltdown showed, however, that exception or branch misprediction events may ... More
A Systematic Evaluation of Transient Execution Attacks and DefensesNov 13 2018May 15 2019Research on transient execution attacks including Spectre and Meltdown showed that exception or branch misprediction events might leave secret-dependent traces in the CPU's microarchitectural state. This observation led to a proliferation of new Spectre ... More
A Systematic Evaluation of Transient Execution Attacks and DefensesNov 13 2018Modern processor optimizations such as branch prediction and out-of-order execution are crucial for performance. Recent research on transient execution attacks including Spectre and Meltdown showed, however, that exception or branch misprediction events ... More
Topological order and topological entropy in classical systemsOct 11 2006Nov 09 2007We show that the concept of topological order, introduced to describe ordered quantum systems which cannot be classified by broken symmetries, also applies to classical systems. Starting from a specific example, we show how to use pure state density matrices ... More
Topological order in a 3D toric code at finite temperatureApr 22 2008Oct 21 2008We study topological order in a toric code in three spatial dimensions, or a 3+1D Z_2 gauge theory, at finite temperature. We compute exactly the topological entropy of the system, and show that it drops, for any infinitesimal temperature, to half its ... More
Topological Quantum GlassinessAug 09 2011Oct 24 2011Quantum tunneling often allows pathways to relaxation past energy barriers which are otherwise hard to overcome classically at low temperatures. However, this is not always the case. In this paper we provide simple exactly solvable examples where the ... More
Components, complements and reflection formulasJan 16 2007Some basic features of the simultaneous inclusion of discrete fibrations and discrete opfibrations in categories over a base category X are considered. In particular, we illustrate the formulas (|P)x = ten(x/X,P) ; (P|)x = hom(X/x,P) which give the reflection ... More
Geodesic completeness for meromorphic metrics: the case of coercive onesSep 18 2001Feb 25 2009This thesis is concerned with extending the idea of geodesic completeness from pseudo-Riemannian to complex geometry: we take, however a completely holomorphicpoint of view; that is to say, a 'metric' will be a (meromorphic) symmetric section of the twice ... More
Painlevé's determinateness theorem extended to proper coveringsJan 29 2009Apr 18 2010We extend Painlev\'e's determinateness theorem to the case of first order ordinary differential equations in the complex domain with known terms allowed be multivalued in the dependent variable as well; multivaluedness is supposed to be resolved by proper ... More
Renormalizing iterated elementary mappings and correspondences of C^2Nov 25 2002May 20 2004After proving a multi-dimensional extension of Zalcman's renormalization lemma and considering maximality problems about dimensions, we find renormalizing polynomial families for iterated elementary mappings, extending this result to some kinds of correspondences ... More
Kernel Convergence Estimates for Diffusions with Continuous CoefficientsNov 01 2007Nov 01 2007We are interested in the kernel of one-dimensional diffusion equations with continuous coefficients as evaluated by means of explicit discretization schemes of uniform step $h>0$ in the limit as $h\to0$. We consider both semidiscrete triangulations with ... More
The geometry of polynomial identitiesFeb 03 2015Jul 22 2015We discuss some geometric invariants of polynomial identities of algebras deduced from Kemer's theory and deduce some quantitative information on codimension and co--length
Complex light: Dynamic phase transitions of a light beam in a nonlinear non-local disordered mediumDec 09 2004Nov 08 2005The dynamics of several light filaments (spatial optical solitons) propagating in an optically nonlinear and non-local random medium is investigated using the paradigms of the physics of complexity. Cluster formation is interpreted as a dynamic phase ... More
On the generation and the nonlinear dynamics of X-waves of the Schroedinger equationApr 05 2004Jul 23 2004The generation of finite energy packets of X-waves is analysed in normally dispersive cubic media by using an X-wave expansion. The 3D nonlinear Schroedinger model is reduced to a 1D equation with anomalous dispersion. Pulse splitting and beam replenishment ... More
Long time dynamics of highly concentrated solitary waves for the nonlinear Schroedinger equationDec 19 2013In this paper we study the behavior of solutions of a nonlinear Schroedinger equation in presence of an external potential, which is allowed to be singular at one point. We show that the solution behaves like a solitary wave for long time even if we start ... More
Solitons in gauge theories: existence and dependence on the chargeDec 19 2013In this paper we review recent results on the existence of non-topological solitons in classical relativistic nonlinear field theories. We follow the Coleman approach, which is based on the existence of two conservation laws, energy and charge. In particular ... More
Finite temperature effective string corrections in (3+1)D SU(2) lattice gauge theoryJun 29 2011Aug 30 2011We study the effective string corrections to the inter-quark potential at finite temperature by simulating the SU(2) lattice gauge theory in four dimensions. We provide the first numerical evidence that the logarithmic correction to the potential, which ... More
TDDFT and Strongly Correlated Systems: Insight From Numerical StudiesJul 14 2007Aug 12 2008We illustrate the scope of Time Dependent Density Functional Theory (TDDFT) for strongly correlated (lattice) models out of equilibrium. Using the exact many body time evolution, we reverse engineer the exact exchange correlation (xc) potential $v_{xc}$ ... More
Mixed polarity reversible Peres gatesMar 25 2015Reversible Peres gates with more than two all over binary-valued control signals are discussed. Methods are disclosed for the low cost realization of this kind of Peres gates without requiring ancillary lines. Proper distribution of the controlled gates ... More
Modelling and Verifying an Object-Oriented Concurrency Model in GROOVEMay 20 2015SCOOP is a programming model and language that allows concurrent programming at a high level of abstraction. Several approaches to verifying SCOOP programs have been proposed in the past, but none of them operate directly on the source code without modifications ... More
Real-time collision detection method for deformable bodiesMay 07 2016This paper presents a real-time solution for collision detection between objects based on the physics properties. Traditional approaches on collision detection often rely on the geometric relationships that computing the intersections between polygons. ... More
Continuum percolation of polydisperse hyperspheres in infinite dimensionsMay 07 2015Aug 10 2015We analyze the critical connectivity of systems of penetrable $d$-dimensional spheres having size distributions in terms of weighed random geometrical graphs, in which vertex coordinates correspond to random positions of the sphere centers and edges are ... More
Free field theory at null infinity and white noise calculus: a BMS invariant dynamical systemJul 25 2006In the context of asymptotically flat spacetimes we exploit techniques proper either of white noise analysis either of dynamical systems in order to develop the Lagrangian and the Hamiltonian approach to a BMS invariant field theory at null infinity.
Simplicial and asymptotical aspects of the holographic principleMar 16 2004In this thesis, we study some aspects of a possible holographic correspondence in two different systems: three dimensional Chern-Simons theory and asymptotically flat space-times. In the former we use simplicial techniques to study CS/WZW correspondence ... More
On approximate controllability of generalized KdV solitonsJun 12 2012May 24 2014We consider the approximate control of solitons in generalized Korteweg-de Vries equations. By introducing a suitable internal bilinear control on the equation, we prove that any soliton is locally null controllable, and moreover, any soliton can be accelerated ... More
Supersymmetric Scaling Violations (II). The general supersymmetric EvolutionFeb 14 2001Using a recursive algorithm to solve the renormalization group equations of N=1 QCD (DGLAP), we describe the most general supersymmetric evolution of the parton distributions. The analysis involves the regular DGLAP evolution, a partial supersymmetric ... More
Spectral Densities and Borel Transforms in Compton ScatteringApr 22 1993We show that the leading double spectral density in sum rules for Compton-like processes can be obtained by simple properties of the Borel transform, extending an approach widely used in the literature on sum rules, and known to be valid only for the ... More
Projected central dark matter fractions and densities in massive early-type galaxies from the Sloan Digital Sky SurveySep 11 2010We investigate in massive early-type galaxies the variation of their two-dimensional central fraction of dark over total mass and dark matter density as a function of stellar mass, central stellar velocity dispersion, effective radius, and central surface ... More
Conferences vs. Journals: Throwing the baby out with the bath water?Mar 06 2015Criticism of the conference model should be put in context. Evidences suggest that the essential features of this model have emerged as responses to challenges posed by current trends of scientific research and the impact of the new techno-economic paradigm, ... More
Quantization of minisuperspaces as ordinary gauge systemsAug 30 2001Simple cosmological models are used to show that gravitation can be quantized as an ordinary gauge system if the Hamilton-Jacobi equation for the model under consideration is separable. In this situation, a canonical transformation can be performed such ... More
1-smooth pro-p groups and the Bloch-Kato conjectureApr 01 2019Let $p$ be a prime. We study pro-$p$ groups $G$ endowed with a continuous homomorphism $G\to1+p\mathbb{Z}_p$ satisfying a formal version of Hilbert 90. These pro-$p$ groups are particularly important in Galois theory because by Kummer theory maximal pro-$p$ ... More
An upper bound for the genus of a curve without points of small degreeMar 05 2012In this paper I prove that for any prime $p$ there is a constant $C_p>0$ such that for any $n>0$ and for any $p$-power $q$ there is a smooth, projective, absolutely irreducible curve over $\mathbb{F}_q$ of genus $g\leq C_p q^n$ without points of degree ... More
Thin homotopy and the holonomy approach to gauge theoriesApr 24 2019We present a brief account of several mathematical developments in the holonomy approach to gauge theory. A cornerstone of such approach is the introduction of group structures on spaces of based loops on a smooth manifold, relying on certain homotopy ... More
Sur une question de BergweilerAug 06 2004Nov 04 2004Nous montrons la densite des cycles repulsifs dans l'ensemble de Julia des fonctions meromorphes transcendentes a une variable complexe, sans utiliser le theoreme des cinq iles d'Ahlfors ni la theorie de Nevanlinna. ----- We prove that repelling cycles ... More
Operator Methods, Abelian Processes and Dynamic ConditioningOct 08 2007Nov 01 2007A mathematical framework for Continuous Time Finance based on operator algebraic methods offers a new direct and entirely constructive perspective on the field and leads to new numerical analysis techniques. This is partly a review paper as it covers ... More
Taut submanifoldsJun 14 2006This is a short, elementary survey article about taut submanifolds. In order to simplify the exposition, we restrict to the case of compact smooth submanifolds of Euclidean or spherical spaces. Some new, partial results concerning taut 4-manifolds are ... More
Adaptive Density Estimation on the Circle by Nearly-Tight FramesApr 02 2015Mar 15 2016This work is concerned with the study of asymptotic properties of nonparametric density estimates in the framework of circular data. The estimation procedure here applied is based on wavelet thresholding methods: the wavelets used are the so-called Mexican ... More
On the soliton dynamics under slowly varying medium for Nonlinear Schrödinger equationsFeb 05 2010Aug 09 2011We consider the problem of the soliton propagation, in a slowly varying medium, for a generalized, variable-coefficients nonlinear Schr\"odinger equation. We prove existence and uniqueness of new soliton-like solutions for a large class of slowly varying ... More
Multiplicity of positive solutions for nonlinear field equations in $\R^{N}$Jan 28 2009Apr 11 2013In this paper we study the multiplicity of positive solutions for nonlinear elliptic equations on $\R^N$. The number of solutions is greater or equal than the number of disjoint intervals on which the nonlinear term is negative. Applications are given ... More
1-smooth pro-p groups and the Bloch-Kato conjectureApr 01 2019Apr 04 2019Let $p$ be a prime. We study pro-$p$ groups $G$ endowed with a continuous homomorphism $G\to1+p\mathbb{Z}_p$ satisfying a formal version of Hilbert 90. These pro-$p$ groups are particularly important in Galois theory because by Kummer theory maximal pro-$p$ ... More
A class of complete embedded minimal submanifolds in noncompact symmetric spacesJul 12 2001We show that a totally geodesic submanifold of a symmetric space satisfying certain conditions admits an extension to a minimal submanifold of dimension one higher, and we apply this result to construct new examples of complete embedded minimal submanifolds ... More
One-parameter 2-equipped posets and classification of their corepresentationsJun 13 2018One-parameter criterion for 2-equipped posets with respect to cerepresentations is stated and proved. The list of sincere one-parameter 2-equipped posets is given as well as a complex matrix classification of all their indecomposables corepresentations. ... More
Local Half-Region Depth for Functional DataDec 14 2015Jan 25 2016Data depth proves successful in the analysis of multivariate data sets, in particular deriving an overall center and assigning ranks to the observed units. Two key features are: the directions of the ordering, from the center towards the outside, and ... More
Thin homotopy and the holonomy approach to gauge theoriesApr 24 2019May 01 2019We survey several mathematical developments in the holonomy approach to gauge theory. A cornerstone of such approach is the introduction of group structures on spaces of based loops on a smooth manifold, relying on certain homotopy equivalence relations ... More
No-arbitrage conditions and absolutely continuous changes of measureDec 16 2013Mar 04 2014We study the stability of several no-arbitrage conditions with respect to absolutely continuous, but not necessarily equivalent, changes of measure. We first consider models based on continuous semimartingales and show that no-arbitrage conditions weaker ... More
Open heavy flavour and J/psi production in proton-proton collisions measured with the ALICE experiment at LHCSep 03 2012Oct 08 2012Open heavy flavour and J/psi production are powerful tools to test pQCD calculations in proton-proton collisions in the new LHC energy regime. In addition, they provide the necessary reference for the ALICE heavy-ion program. The ALICE experiment at the ... More
The geometric phase of stock tradingMar 17 2016Geometric phases describe how in a continuous-time dynamical system the displacement of a variable (called phase variable) can be related to other variables (shape variables) undergoing a cyclic motion, according to an area rule. The aim of this paper ... More
BMS field theory and holography in asymptotically flat space-timesOct 04 2004Nov 25 2004We explore the holographic principle in the context of asymptotically flat space-times by means of the asymptotic symmetry group of this class of space-times, the so called Bondi-Metzner-Sachs (BMS) group. In particular we construct a (free) field theory ... More
A counterexample to 'Algebraic function fields with small class number'Nov 25 2013I give a counter example of function field over GF(2) of genus 4 with class number one. This result contradicts a previous result in [2], Section 2 so that proof is wrong.
Inelastic character of solitons of slowly varying gKdV equationsJul 26 2011In this paper we describe the inelastic character of solitons of some slowly varying gKdV equations. We give precise lower bounds, in the energy space, of the defect induced by the potential on the solution as time goes to infinite. For the proof, we ... More
Electrodynamics in the presence of an axionApr 09 1992The low energy limit of an axion field coupled to gauge fields is investigated through the behaviour of the gauge field propagator in a local vaccum angle background. The local (singular) part of the effective action for the axion field is calculated ... More
Solitons in Carbon NanotubesOct 19 1998Apr 29 1999The symmetries of spontaneous lattice distortions in carbon nanotubes are investigated. When the degeneracy of the ground states remains discrete, there are solitons or domain walls connecting the different symmetry broken vaccua. These solitons, similarly ... More
Linear and nonlinear Anderson localization in a curved potentialMay 13 2013We investigate disorder induced localization in the presence of nonlinearity and curvature. We numerically analyze the time-resolved three-dimensional expansion of a wave-packet in a bended cigar shaped potential with a focusing Kerr-like interaction ... More
Localization and shock waves in curved manifolds for the Gross-Pitaevskii equationFeb 14 2013Apr 04 2013We investigate the dynamics of a Bose-Einstein condensate in a progressively bended three dimensional cigar shaped potential. The interplay between geometry and nonlinearity is considered. At high curvature, topological localization occurs and becomes ... More
New perspectives in the ultrafast spectroscopy of many-body excitations in correlated materialsJun 06 2016Ultrafast spectroscopies constitute a fundamental tool to investigate the dynamics of non-equilibrium many-body states in correlated materials. Two-pulses (pump-probe) experiments have shed new light on the interplay between high-energy electronic excitations ... More
Connected components of moduli spaces of generalised Kummer varietiesAug 23 2016Moduli spaces of polarised (with fixed polarisation type) irreducible holomorphic symplectic manifolds deformation equivalent to Hilbert schemes of points on $K3$ surfaces are not connected in general and A. Apostolov counted the number of their components. ... More
The strong predictable representation property in initially enlarged filtrationsAug 13 2015Oct 07 2015We provide a general account of the strong predictable representation property in filtrations initially enlarged with a random variable L. We prove that the strong predictable representation property can always be transferred to the enlarged filtration ... More
Invariants of commuting matricesJan 21 2015Feb 11 2015We comment two papers of Domokos and Vaccarino proving that the restriction to diagonal matrices of the scheme of commuting matrices is an isomorphism when restricted to invariants to the symmetric group invariants.
What happened to PI theory?Mar 22 2014This paper is a request for help to clarify a rather confusing state of the Theory.
Physical propositions and quantum languagesNov 22 2006The word \textit{proposition} is used in physics with different meanings, which must be distinguished to avoid interpretational problems. We construct two languages $\mathcal{L}^{\ast}(x)$ and $\mathcal{L}(x)$ with classical set-theoretical semantics ... More
A Pragmatic Interpretation of Quantum LogicJul 13 2005Oct 05 2005Scholars have wondered for a long time whether quantum mechanics (QM) subtends a quantum concept of truth which originates quantum logic (QL) and is radically different from the classical (Tarskian) concept of truth. We show in this paper that QL can ... More
Short-term Memory of Deep RNNFeb 02 2018The extension of deep learning towards temporal data processing is gaining an increasing research interest. In this paper we investigate the properties of state dynamics developed in successive levels of deep recurrent neural networks (RNNs) in terms ... More
Computer Interfaces to Organizations: Perspectives on Borg-Human Interaction DesignDec 08 2017We use the term borg to refer to the complex organizations composed of people, machines, and processes with which users frequently interact using computer interfaces and websites. Unlike interfaces to pure machines, we contend that borg-human interaction ... More
A Pragmatic Interpretation of Quantum LogicAug 31 2014Dec 16 2015Scholars have wondered for a long time whether the language of quantum mechanics introduces a quantum notion of truth which is formalized by quantum logic (QL) and is incompatible with the classical (Tarskian) notion. We show that QL can be interpreted ... More
Distributed multi-object tracking over sensor networks: a random finite set approachJul 12 2015The aim of the present dissertation is to address distributed tracking over a network of heterogeneous and geographically dispersed nodes (or agents) with sensing, communication and processing capabilities. Tracking is carried out in the Bayesian framework ... More
Cohomology of absolute Galois groupsDec 24 2014The main problem this thesis deals with is the characterization of profinite groups which are realizable as absolute Galois groups of fields: this is currently one of the major problems in Galois theory. Usually one reduces the problem to the pro-$p$ ... More
A Holomorphic Point of View about Geodesic CompletenessDec 20 1999Jun 16 2008We propose to apply the idea of analytical continuation in the complex domain to the problem of geodesic completeness. We shall analyse rather in detail the cases of analytical warped products of real lines, these ones in parallel with their complex counterparts, ... More
Optimum weight chamber examples of moduli spaces of stable parabolic bundles in genus 0May 14 2017Apr 02 2018We present an explicit construction of the moduli spaces of rank 2 stable parabolic bundles of parabolic degree 0 over the Riemann sphere, corresponding to "optimum" open weight chambers of parabolic weights in the weight polytope. The complexity of the ... More
Balanced Category Theory IIApr 11 2009Apr 27 2009In the first part, we further advance the study of category theory in a strong balanced factorization category C [Pisani, 2008], a finitely complete category endowed with two reciprocally stable factorization systems such that X \to 1 is in M iff it is ... More
Scale Invariant Effective Hamiltonians for a Graph with a Small Compact CoreMar 05 2019We consider a compact metric graph of size $\varepsilon$, and attach to it several edges (leads) of length of order one (or of infinite length). As $\varepsilon$ goes to zero, the graph $\mathcal{G}^\varepsilon$ obtained in this way looks like the star-graph ... More
Weak and strong no-arbitrage conditions for continuous financial marketsFeb 28 2013May 14 2014We propose a unified analysis of a whole spectrum of no-arbitrage conditions for financial market models based on continuous semimartingales. In particular, we focus on no-arbitrage conditions weaker than the classical notions of No Arbitrage and No Free ... More
Pomerons and Lattices: a Progress ReportAug 23 1996We report on some attempts to use lattice QCD to investigate topics in strong interactions phenomenology which are usually interpreted in terms of soft Pomeron exchange.
Remarks on groups of bundle automorphisms over the Riemann sphereJul 13 2016In this note, we provide a structural characterization of the group of automorphisms of an arbitrary Birkhoff-Grothendieck splitting $\bigoplus_{i=1}^{r} \mathcal{O}(m_{i})$ over the Riemann sphere by considering its action on an optimal space of generalized ... More
On the electrodynamics of moving particles in a quasi flat spacetime with Lorentz violation and its cosmological implicationsAug 23 2013Nov 01 2016This research aims to develop a new approach toward a consistent coupling of electromagnetic and gravitational fields by using an electron that couples with a weak gravitational potential by means of its electromagnetic field. We find the value of the ... More
Large Scale Deep Convolutional Neural Network Features Search with LuceneMar 31 2016Jul 20 2016In this work, we propose an approach to index Deep Convolutional Neural Network Features to support efficient content-based retrieval on large image databases. To this aim, we have converted the these features into a textual form, to index them into an ... More
Remarks on the Reeh-Schlieder property for higher spin free fields on curved spacetimesFeb 25 2011Apr 07 2011The existence of states enjoying a weak form of the Reeh-Schlieder property has been recently established on curved backgrounds and in the framework of locally covariant quantum field theory. Since only the example of a real scalar field has been discussed, ... More
Can we implement the holographic principle in asymptotically flat spacetimes?Nov 02 2005We discuss some recent results in the quest to implement the holographic principle in asymptotically flat spacetimes. In particular we introduce the key ingredients of the candidate dual theory which lives at null infinity and it is invariant under the ... More
The Gardner equation and the stability of multi-kink solutions of the mKdV equationJun 03 2011Aug 09 2011Multi-kink solutions of the defocusing, modified Korteweg-de Vries equation (mKdV) found by Grosse are shown to be globally $H^1$-stable. Stability in the one-kink case was previously established by Zhidkov, and Merle-Vega. The proof uses transformations ... More
Negativity and topological order in the toric codeJun 20 2013Sep 27 2013In this manuscript we study the behaviour of the entanglement measure dubbed negativity in the context of the toric code model. Using a method introduced recently by Calabrese, Cardy and Tonni [Phys. Rev. Lett. 109, 130502 (2012)], we obtain an exact ... More
Quantum GlassinessApr 07 2004Feb 19 2005Describing matter at near absolute zero temperature requires understanding a system's quantum ground state and the low energy excitations around it, the quasiparticles, which are thermally populated by the system's contact to a heat bath. However, this ... More
Supersymmetric Scaling Violations (I). Solving the Supersymmetric DGLAP EvolutionSep 19 2000Jan 29 2002We analize the renormalization group equations of supersymmetric QCD with N=1 for the evolution of parton distributions. For this purpose we develope a simple recursive algorithm in x-space to include both regular regions and supersymmetric regions in ... More
Cylindrical thin-shell wormholes and energy conditionsMar 16 2012We prove the impossibility of cylindrical thin-shell wormholes supported by matter satisfying the energy conditions everywhere, under reasonable assumptions about the asymptotic behaviour of the - in general different - metrics at each side of the throat. ... More
Path integral for minisuperspaces and its relation with non equivalent canonical quantizationsFeb 19 2003The relation between a recently proposed path integral for minisuperspaces and different canonical quantizations is established. The step of the procedure where a choice between non equivalent theories is made is identified. Coordinates avoiding such ... More
Quantum gravity simulation by non-paraxial nonlinear opticsJun 25 2014We show that an analog of the physics at the Planck scale can be found in the propagation of tightly focused laser beams. Various equations that occur in generalized quantum mechanics are formally identical to those describing the nonlinear nonlocal propagation ... More
Quantum X-waves in Kerr media and the progressive undistorted squeezed vacuumSep 20 2004A quantum theory of 3D X-shaped optical bullets in Kerr media is presented. The existence of progressive undistorted squeezed vacuum is predicted. Applications to quantum non-demolition experiments, entanglement and interferometers for gravitational waves ... More
Graph-like asymptotics for the Dirichlet Laplacian in connected tubular domainsFeb 18 2011Feb 28 2011We consider the Dirichlet Laplacian in a waveguide of uniform width and infinite length which is ideally divided into three parts: a "vertex region", compactly supported and with non zero curvature, and two "edge regions" which are semi-infinite straight ... More
Stochastic Integrals and Abelian ProcessesNov 19 2007We study triangulation schemes for the joint kernel of a diffusion process with uniformly continuous coefficients and an adapted, non-resonant Abelian process. The prototypical example of Abelian process to which our methods apply is given by stochastic ... More
A weaker geodesic completeness and Clifton-Pohl torusOct 29 2002We propose a new definition of geodesic completeness, based on analytical continuation in the complex domain: we apply this idea to Clifton-Pohl torus, relating, for each geodesic, completeness to the value of a function of initial conditions, called ... More
Bipolar spacesDec 09 2005Some basic features of the simultaneous inclusion of discrete fibrations and discrete opfibrations on a category A in the category of categories over A are studied; in particular, the reflections and the coreflections of the latter in the former are considered, ... More
Non-linear response in extended systems: a real-time approachSep 30 2016In this thesis we present a new formalism to study linear and non-linear response in extended systems. Our approach is based on real-time solution of an effective Schr\"odinger equation. The coupling between electrons and external field is described by ... More
MGP versus Kochen-Specker condition in hidden variables theoriesNov 09 2002Jan 29 2004Hidden variables theories for quantum mechanics are usually assumed to satisfy the KS condition. The Bell-Kochen-Specker theorem then shows that these theories are necessarily contextual. But the KS condition can be criticized from an operational viewpoint, ... More
Truth and Completeness in Quantum Mechanics: A Semantic ViewpointOct 26 2005The Einstein, Podolski and Rosen (EPR) argument aiming to prove the incompleteness of quantum mechanics (QM) was opposed by most EPR's contemporary physicists and is not accepted within the standard interpretation of QM, which maintains that QM is a complete ... More
Holonomy-flux spinfoam amplitudeNov 20 2012We introduce a holomorphic representation for the Lorentzian EPRL spinfoam on arbitrary 2-complexes. The representation is obtained via the Ashtekar-Lewandowski-Marolf-Mour\~ao-Thiemann heat kernel coherent state transform. The new variables are classical ... More
Einstein-Regge equations in spinfoamsOct 26 2011We consider spinfoam quantum gravity on a spacetime decomposition with many 4-simplices, in the double scaling limit in which the Immirzi parameter $\gamma$ is sent to zero (flipped limit) and the physical area in Planck units ($\gamma$ times the spin ... More
A critical analysis of the concept of time in physicsAug 16 2018Sep 02 2018This paper puts forward a broad critical analysis of the concept of physical time. Clock effect is conceived as a consequence of the variation of the gravitational or pseudo gravitational potential, and it is remarked that only some real clocks measure ... More
An example of a covering surface with 'movable' natural boundariesAug 06 2004Jul 11 2008We exhibit an example of covering surface of C*, arising from analytical continuation of a holomorphic germ and failing to be a topological covering, due to singular points and regular ones being projected over the same slits in C*.
Bloch-Kato pro-p groups and locally powerful groupsNov 19 2012A Bloch-Kato pro-p group G is a pro-p group with the property that the F_p-cohomology ring of every closed subgroup of G is quadratic. It is shown that either such a pro-p group G contains no closed free pro-p groups of infinite rank, or there exists ... More
Finite quotients of Galois pro-$p$ groups and rigid fieldsMar 22 2015For a prime number $p$, we show that if two certain canonical finite quotients of a finitely generated Bloch-Kato pro-$p$ group $G$ coincide, then $G$ has a very simple structure, i.e., $G$ is a $p$-adic analytic pro-$p$ group. This result has a remarkable ... More