Results for "Tommaso Guaita"

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Gaussian TDVP for the Bose-Hubbard modelJul 10 2019We systematically extend Bogoliubov theory beyond the mean field approximation of the Bose- Hubbard model in the superfluid phase. Our approach is based on the time dependent variational principle applied to the family of all Gaussian states (i.e., Gaussian ... More
Gaussian time dependent variational principle for the Bose-Hubbard modelJul 10 2019Jul 18 2019We systematically extend Bogoliubov theory beyond the mean field approximation of the Bose-Hubbard model in the superfluid phase. Our approach is based on the time dependent variational principle applied to the family of all Gaussian states (i.e. Gaussian ... More
On the (im)possibility of extending the GRW model to relativistic particlesJul 04 2019We investigate the relativistic properties of the distinguishable non-interacting relativistic GRW model presented in arXiv:quant-ph/0406094v2. We discuss how the relativistic properties of this theory are contingent on the points of collapse being time-like ... More
Quantum backflow effect and nonclassicalityApr 25 2016The quantum backflow effect is a counterintuitive behavior of the probability current of a free particle, which may be negative even for states with vanishing negative momentum component. Here we address the notion of nonclassicality arising from the ... More
Causal sets from simple models of computationApr 19 2010Causality among events is widely recognized as a most fundamental structure of spacetime, and causal sets have been proposed as discrete models of the latter in the context of quantum gravity theories, notably in the Causal Set Programme. In the rather ... More
Search For New Particles in Multijet Final States at the TevatronAug 18 1997We present the latest results of the searches for new particles in hadronic final states performed in proton-antiproton collisions at a center of mass energy of 1.8 TeV. The large data samples collected with the CDF and D0 detectors at the Tevatron collider ... More
Spheroids scaling relations over cosmic timeNov 02 2006I report on recent measurements of two scaling relations of spheroids in the distant universe: the Fundamental Plane, and the relation between lensing velocity dispersion and stellar velocity dispersion. The joint analysis of the two scaling relations ... More
Measurements of time-dependent $C\!P$ violation and mixing in charm at LHCbJul 02 2019The LHCb experiment has opened the possibility to test mixing and $C\!P$ violation in the charm sector with unprecedented precision thanks to the huge number of charm hadron decays collected, $\mathcal{O}(10^8)$. The first observation of $C\!P$ violation ... More
Sapo: Reachability Computation and Parameter Synthesis of Polynomial Dynamical SystemsJul 08 2016Sapo is a C++ tool for the formal analysis of polynomial dynamical systems. Its main features are: 1) Reachability computation, i.e., the calculation of the set of states reachable from a set of initial conditions, and 2) Parameter synthesis, i.e., the ... More
Desingularizing isolated conical singularities: Uniform estimates via weighted Sobolev spacesMay 19 2010Nov 12 2012We define a very general "parametric connect sum" construction which can be used to eliminate isolated conical singularities of Riemannian manifolds. We then show that various important analytic and elliptic estimates, formulated in terms of weighted ... More
Analytic and elliptic estimates on non-compact manifolds via weighted Sobolev spacesFeb 05 2010May 19 2010This paper is a self-contained presentation of certain aspects of the theory of weighted Sobolev spaces and elliptic operators on non-compact Riemannian manifolds. Specifically, we discuss (i) the standard and weighted Sobolev Embedding Theorems for general ... More
Type-I Error or Mass Bias ? An Investigation on the Omega_b DiscoveryOct 12 2009The D0 and CDF collaborations recently published two independent analyses that both claim to represent the observation of the Omega_b particle, a baryon made up by a (bss) quark combination. Both signals are estimated to exceed the statistical significance ... More
Towards a Theory of the Glass CrossoverJul 16 2013The standard field-theoretical procedure to study the effect of long wavelength fluctuations on a genuine second-order phase transition is applied to the Mode-Coupling-Theory (MCT) dynamical singularity at $T_c$ in the $\beta$ regime. Technically this ... More
On the Complexity of the Bethe Lattice Spin GlassApr 30 2004Jun 07 2004A theory for the complexity of the Bethe lattice spin-glass is developed applying to the cavity-method scheme of Mezard and Parisi the results recently obtained in the context of the Sherrington-Kirkpatrick model. The crucial ingredient is the introduction ... More
Ultrametricity Between States at Different Temperatures in Spin-GlassesJul 02 2002We prove the existence of correlations between the equilibrium states at different temperatures of the multi-$p$-spin spherical spin-glass models with continuous replica symmetry breaking: there is no chaos in temperature in these models. Furthermore, ... More
Recent CMS ResultsOct 25 2012The CMS experiment obtained a large number of groundbreaking results from the analysis of 7- and 8-TeV proton-proton collisions produced so far by the Large Hadron Collider at CERN. In this brief summary only a sample of those results will be discussed. ... More
A note on symmetric separation in Banach spacesApr 29 2019We present some new results on the symmetric Kottman's constant $K^s(X)$ of a Banach space $X$ and its relationship with the Kottman constant. We show that $K^s(X)>1$, for every infinite-dimensional Banach space, thereby solving a problem by J.M.F. Castillo ... More
An enriched mixture model for functional clusteringJul 04 2019There is an increasingly rich literature about Bayesian nonparametric models for clustering functional observations. However, most of the recent proposals rely on infinite-dimensional characterizations that might lead to overly complex cluster solutions. ... More
A replica trick for rare samplesMar 07 2014In the context of disordered systems with quenched Hamiltonians I address the problem of characterizing rare samples where the thermal average of a specific observable has a value different from the typical one. These rare samples can be selected through ... More
Super-Cooled Liquids: Equivalence between Mode-Coupling Theory and Replica ApproachSep 25 2012Feb 20 2013We show that the replica approach to glassy dynamics provides, in spite of its static nature, a characterization of critical dynamics in the $\beta$-regime of super-cooled liquids that is equivalent to the one of Mode-Coupling-Theory, both qualitatively ... More
The Glass Crossover from Mean-Field Spin-Glasses to Supercooled LiquidsJul 22 2015Stochastic-Beta-Relaxation (SBR) provides a characterisation of the glass crossover in discontinuous Spin-Glasses and Supercoooled liquid. Notably it can be derived through a rigorous computation from a dynamical Landau theory. In this paper I will discuss ... More
Special Lagrangian conifolds, I: Moduli spaces (extended version)Nov 12 2012This is the extended version of the paper "Special Lagrangian conifolds, I: Moduli spaces", which discusses the deformation theory of special Lagrangian (SL) conifolds in complex space C^m. Conifolds are a key ingredient in the compactification problem ... More
Search for the Standard Model Higgs Boson at CMSOct 19 2009The prospects for the search of the Standard Model Higgs boson with the CMS experiment at the LHC are presented. The analyses rely on a full simulation of the detector response and emphasis is put on explicit strategies for the measurement of experimental ... More
Searches for the Standard Model Higgs Boson at the TevatronMay 17 2005The CDF and D0 experiments at the Tevatron have searched for the Standard Model Higgs boson in data collected between 2001 and 2004. Upper limits have been placed on the production cross section times branching ratio to b-antib pairs or WW pairs as a ... More
Qubit-Controlled Displacements in Markovian EnvironmentsSep 09 2012Sep 15 2012We study a particular form of interaction Hamiltonian between qubits and quantum harmonic oscillators, whose closed system dynamics results in qubit controlled displacement operations. We show how this interaction is realizable in many setups, including ... More
Measuring dark energy with the integrated Sachs-Wolfe effectMay 23 2008I present to this conference our latest measurements of the integrated Sachs-Wolfe (ISW) effect. After a brief review of the reasons for which this effect arises and of the technique to detect it by cross-correlating the cosmic microwave background (CMB) ... More
Impulsive quantum measurements: restricted path integral versus von Neumann collapseJan 24 1996The relation between the restricted path integral approach to quantum measurement theory and the commonly accepted von Neumann wavefunction collapse postulate is presented. It is argued that in the limit of impulsive measurements the two approaches lead ... More
Extremal length in higher dimensions and complex systolic inequalitiesApr 16 2019Extremal length is a classical tool in 1-dimensional complex analysis for building conformal invariants. We propose a higher-dimensional generalization for complex manifolds and provide some ideas on how to estimate and calculate it. We also show how ... More
A locally hyperbolic 3-manifold that is not homotopy equivalent to any hyperbolic 3-manifoldDec 06 2018We construct a locally hyperbolic 3-manifold $M$ such that $\pi_ 1(M)$ has no divisible subgroups. We then show that $M$ is not homotopy equivalent to any complete hyperbolic manifold.
Maximal Hypoellipticity for Left-Invariant Differential Operators on Lie GroupsNov 12 2018Given a differential operator defined in terms of left-invariant vector fields on a Lie group, we prove that the local condition defining maximal hypoellipticity is equivalent to a global estimate if the operator is left invariant. As a consequence, we ... More
W and Z Cross Sections at the TevatronJun 03 2003The CDF and D0 experiments at the Tevatron have used p-pbar collisions at sqrt(s)=1.96 TeV to measure the cross section of W and Z boson production using several leptonic final states. An indirect measurement of the total W width has been extracted, and ... More
Special Lagrangian conifolds, I: Moduli spacesFeb 05 2010Nov 12 2012We discuss the deformation theory of special Lagrangian (SL) conifolds in complex space C^m. Conifolds are a key ingredient in the compactification problem for moduli spaces of compact SLs in Calabi-Yau manifolds. This category allows for the simultaneous ... More
Dynamical Landau Theory of the Glass CrossoverMar 09 2016Jun 20 2016I introduce a dynamical field theory to describe the glassy behavior in supercooled liquids. The mean-field approximation of the theory predicts a dynamical arrest transition, as in ideal Mode-Coupling-Theory and mean-field discontinuous Spin-Glass Models. ... More
Replica-symmetry-breaking transitions and off-equilibrium dynamicsMay 09 2013Sep 25 2013I consider branches of Replica-Symmetry-Breaking (RSB) solutions in Glassy systems that display a dynamical transition at a temperature $T_d$ characterized by a Mode-Coupling-Theory dynamical behavior. Below $T_d$ these branches of solutions are considered ... More
Long-wavelength fluctuations lead to a model of the glass crossoverMay 26 2014The effect of long wavelength fluctuations on the Mode-Coupling-Theory (MCT) dynamical singularity at $T_c$ in the $\beta$ regime is studied by means of the standard field-theoretical procedure for a genuine second-order phase transition. The resulting ... More
Against Chaos in Temperature in Mean-Field Spin-Glass ModelsMar 19 2001We study the problem of chaos in temperature in some mean-field spin-glass models by means of a replica computation over a model of coupled systems. We propose a set of solutions of the saddle point equations which are intrinsically non-chaotic and solve ... More
The NA62 experiment at CERN: status and perspectivesJan 28 2011The future program of the NA62 experiment at CERN SPS is currently in advanced stage of development. The main goal of the experiment is to measure the branching ratio of the ultra-rare decay K^+ -> pi+\nu\nubar, by detecting approximately 80 events with ... More
Endpoint results for the Riesz transform of the Ornstein-Uhlenbeck operatorJan 22 2018In this paper we introduce a new atomic Hardy space $X^1(\gamma)$ adapted to the Gauss measure $\gamma$, and prove the boundedness of the first order Riesz transform associated with the Ornstein-Uhlenbeck operator from $X^1(\gamma)$ to $L^1(\gamma)$. ... More
Observation of Z Decays to b Quark Pairs at the Tevatron ColliderJun 23 1998A search for Z boson decays to pairs of b-quark jets has been performed in the full dataset collected with the CDF detector at the Tevatron proton-antiproton collider. After the selection of a pure sample of bb events by means of the identification of ... More
Special Lagrangian conifolds, II: Gluing constructions in C^mSep 15 2011Nov 12 2012We prove two gluing theorems for special Lagrangian (SL) conifolds in complex space C^m. Conifolds are a key ingredient in the compactification problem for moduli spaces of compact SLs in Calabi-Yau manifolds. In particular, our theorems yield the first ... More
Tap Complexity, the Cavity Method and SupersymmetryMar 10 2004Mar 11 2004We compute the Bray and Moore (BM) TAP Complexity for the Sherrington-Kirkpatrick model through the cavity method, showing that some essential modifications are needed with respect to the standard formulation of the method. This allows to understand various ... More
A model for discussing entropy and time reversibilitySep 08 2014Sep 09 2014In this article we discuss a model used to introduce the concept of entropy with secondary school students. It can be used to discuss with students the reversibility of time, the tendency towards homogeneity and the link between probability theory and ... More
A locally hyperbolic 3-manifold that is not hyperbolicNov 30 2017We construct a locally hyperbolic 3-manifold $M_\infty$ such that $\pi_ 1(M_\infty)$ has no divisible subgroup. We then show that $M_\infty$ is not homeomorphic to any complete hyperbolic manifold. This answers a question of Agol [DHM06,Mar07].
Hyperbolization of infinite-type 3-manifoldsApr 25 2019We study the class $\mathcal M^B$ of 3-manifolds $M$ that have a compact exhaustion $M=\cup_{i\in\mathbb N} M_i$ satisfying: each $M_i$ is hyperbolizable with incompressible boundary and each component of $\partial M_i$ has genus at most $g= g(M)$. For ... More
Singular integrals and Hardy type spaces for the inverse Gauss measureJan 26 2018Let $\gamma_{-1}$ be the absolutely continuous measure on $\mathbb{R}^n$ whose density is the reciprocal of a Gaussian and consider the natural weighted Laplacian $\mathcal{A}$ on $L^2(\gamma_{-1})$. In this paper, we prove boundedness and unboundedness ... More
A registration method for model order reduction: data compression and geometry reductionJun 26 2019We propose a general --- i.e., independent of the underlying equation --- registration method for parameterized Model Order Reduction. Given the spatial domain $\Omega \subset \mathbb{R}^d$ and a set of snapshots $\{ u^k \}_{k=1}^{n_{\rm train}}$ over ... More
An offline/online procedure for dual norm calculations of parameterized functionals: empirical quadrature and empirical test spacesMay 21 2018Feb 06 2019We present an offline/online computational procedure for computing the dual norm of parameterized linear functionals. The key elements of the approach are (i) an empirical test space for the manifold of Riesz elements associated with the parameterized ... More
Qualitative Features at the Glass CrossoverMar 11 2014Jun 19 2014We discuss some generic features of the dynamics of glass-forming liquids close to the glass transition singularity of the idealized mode-coupling theory (MCT). The analysis is based on a recent model by one of the authors for the intermediate-time dynamics ... More
Step-wise responses in mesoscopic glassy systems: a mean field approachAug 14 2006Oct 18 2007We study statistical properties of peculiar responses in glassy systems at mesoscopic scales based on a class of mean-field spin-glass models which exhibit 1 step replica symmetry breaking. Under variation of a generic external field, a finite-sized sample ... More
Bayesian evidence of non-standard inflation: isocurvature perturbations and running spectral indexJul 16 2014Jul 27 2015Bayesian model comparison penalizes models with more free parameters that are allowed to vary over a wide range, and thus offers the most robust method to decide whether some given data require new parameters. In this paper, we ask a simple question: ... More
One-dimensional solutions of non-local Allen-Cahn-type equations with rough kernelsOct 09 2015We are interested in the study of local and global minimizers for an energy functional of the type $$ \frac{1}{4} \iint_{\mathbb{R}^{2 N} \setminus \left( \mathbb{R}^N \setminus \Omega \right)^2} |u(x) - u(y)|^2 K(x - y) \, dx dy + \int_{\Omega} W(u(x)) ... More
The X-ray spectral properties of X-ray selected AGN : ROSAT spectra of EMSS AGNMay 21 1996Using a sample of 63 AGNs extracted from the $Einstein$ Extended Medium Sensitivity Survey (EMSS), we study the X-ray spectral properties of X-ray selected AGN in the 0.1$-$2.4 keV ROSAT band. These objects are all the EMSS AGN detected with more than ... More
Spectral triples for nested fractalsJan 29 2016It is shown that, for nested fractals [T.Lindstrom, Mem. Amer. Math. Soc. 420, 1990], the main structural data, such as the Hausdorff dimension and measure, the geodesic distance induced by the immersion in $R^n$ (when it exists), and the self-similar ... More
The Inverse Bagging Algorithm: Anomaly Detection by Inverse Bootstrap AggregatingNov 24 2016For data sets populated by a very well modeled process and by another process of unknown probability density function (PDF), a desired feature when manipulating the fraction of the unknown process (either for enhancing it or suppressing it) consists in ... More
Comment on "Feshbach-Einstein Condensates" by V. G. Rousseau and P. J. H. DenteneerJul 12 2010In a recent paper (Phys. Rev. Lett. 102, 015301 (2009), arXiv:0810.3763) Rousseau and Denteneer claim that an unconventional "super-Mott" (SM) phase is realized by bosons trapped in an optical lattice close to a Feshbach resonance with a molecular state. ... More
Dimensions and spectral triples for fractals in R^NApr 16 2004Jun 30 2005Two spectral triples are introduced for a class of fractals in R^n. The definitions of noncommutative Hausdorff dimension and noncommutative tangential dimensions, as well as the corresponding Hausdorff and Hausdorff-Besicovitch functionals considered ... More
Identification of an average temperature and a dynamical pressure in a multitemperature mixture of fluidsJul 17 2008We present a classical approach of a mixture of compressible fluids when each constituent has its own temperature. The introduction of an average temperature together with the entropy principle dictates the classical Fick law for diffusion and also novel ... More
Tangential dimensions II. MeasuresMay 10 2004Notions of (pointwise) tangential dimension are considered, for measures of R^n. Under regularity conditions (volume doubling), the upper resp. lower dimension at a point x of a measure can be defined as the supremum, resp. infimum, of local dimensions ... More
Quantum Monte Carlo calculation of entanglement Renyi entropies for generic quantum systemsMar 26 2012We present a general scheme for the calculation of the Renyi entropy of a subsystem in quantum many-body models that can be efficiently simulated via quantum Monte Carlo. When the simulation is performed at very low temperature, the above approach delivers ... More
The problem of completeness for Gromov-Hausdorff metrics on C*-algebrasFeb 01 2005Apr 28 2005It is proved that the family of equivalence classes of Lip-normed C*-algebras introduced by M. Rieffel, up to isomorphisms preserving the Lip-seminorm, is not complete w.r.t. the matricial quantum Gromov-Hausdorff distance introduced by D. Kerr. This ... More
Infinitely many cyclic solutions to the Hamilton-Waterloo problem with odd length cyclesJan 28 2015Mar 31 2016It is conjectured that for every pair $(\ell,m)$ of odd integers greater than 2 with $m \equiv 1\; \pmod{\ell}$, there exists a cyclic two-factorization of $K_{\ell m}$ having exactly $(m-1)/2$ factors of type $\ell^m$ and all the others of type $m^{\ell}$. ... More
Weighted sub-Laplacians on Métivier Groups: Essential Self-Adjointness and SpectrumOct 31 2016Let $G$ be a M\'etivier group and let $N$ be any homogeneous norm on $G$. For $\alpha>0$ denote by $w_\alpha$ the function $e^{-N^\alpha}$ and consider the weighted sub-Laplacian $\mathcal{L}^{w_\alpha}$ associated with the Dirichlet form $\phi \mapsto ... More
Chopped random-basis quantum optimizationMar 04 2011Aug 22 2011In this work we describe in detail the "Chopped RAndom Basis" (CRAB) optimal control technique recently introduced to optimize t-DMRG simulations [arXiv:1003.3750]. Here we study the efficiency of this control technique in optimizing different quantum ... More
Electron correlation in C_(4N+2) carbon rings: aromatic vs. dimerized structuresMar 17 2000Mar 27 2000The electronic structure of C_(4N+2) carbon rings exhibits competing many-body effects of Huckel aromaticity, second-order Jahn-Teller and Peierls instability at large sizes. This leads to possible ground state structures with aromatic, bond angle or ... More
Chaplygin gas in light of recent Integrated Sachs--Wolfe effect dataJun 07 2006We investigate the possibility of constraining Chaplygin dark energy models with current Integrated Sachs Wolfe effect data. In the case of a flat universe we found that generalized Chaplygin gas models must have an energy density such that $\Omega_c ... More
Time-Frequency Packing for High Capacity Coherent Optical LinksApr 16 2014Jul 11 2014We consider realistic long-haul optical links, with linear and nonlinear impairments, and investigate the application of time-frequency packing with low-order constellations as a possible solution to increase the spectral efficiency. A detailed comparison ... More
Quantum mean-field approximation for lattice quantum models: truncating quantum correlations, and retaining classical onesAug 03 2016In a recent work [D. Malpetti and T. Roscilde, arXiv:1605.04223] we have shown that in quantum many-body systems at finite temperature, two-point correlations can be formally separated into a thermal part, and a quantum part -- and that generically quantum ... More
Structure formation from non-Gaussian initial conditions: multivariate biasing, statistics, and comparison with N-body simulationsNov 02 2009Mar 04 2010We study structure formation in the presence of primordial non-Gaussianity of the local type with parameters f_NL and g_NL. We show that the distribution of dark-matter halos is naturally described by a multivariate bias scheme where the halo overdensity ... More
Chaos in Temperature in Diluted Mean-Field Spin-GlassesFeb 08 2010We consider the problem of temperature chaos in mean-field spin-glass models defined on random lattices with finite connectivity. By means of an expansion in the order parameter we show that these models display a much stronger chaos effect than the fully ... More
Large Deviations of the Free-Energy in Diluted Mean-Field Spin-GlassOct 23 2009Sample-to-sample free energy fluctuations in spin-glasses display a markedly different behaviour in finite-dimensional and fully-connected models, namely Gaussian vs. non-Gaussian. Spin-glass models defined on various types of random graphs are in an ... More
Phase diagram and large deviations in the free-energy of mean-field spin-glassesNov 10 2008Apr 07 2009We consider the probability distribution of large deviations in the spin-glass free energy for the Sherrington-Kirkpatrick mean field model, i.e. the exponentially small probability of finding a system with intensive free energy smaller than the most ... More
Large Deviations in the Free-Energy of Mean-Field Spin-GlassesJun 08 2007Jun 20 2007We compute analytically the probability distribution of large deviations in the spin-glass free energy for the Sherrington-Kirkpatrick mean field model, i.e. we compute the exponentially small probability of finding a system with intensive free energy ... More
Rydberg-dressing of atoms in optical latticesAug 26 2013Jan 22 2014We study atoms in optical lattices whose electronic ground state is off-resonantly coupled to a highly excited state with strong binary interactions. We present a time-dependent treatment of the resulting quantum dynamics, which -- contrary to recent ... More
Quantum thermostatted disordered systems and sensitivity under compressionJun 26 2017Sep 26 2017A one-dimensional quantum system with off diagonal disorder, consisting of a sample of conducting regions randomly interspersed within potential barriers is considered. Results mainly concerning the large $N$ limit are presented. In particular, the effect ... More
How to Compute Loop Corrections to Bethe ApproximationJun 29 2005We introduce a method for computing corrections to Bethe approximation for spin models on arbitrary lattices. Unlike cluster variational methods, the new approach takes into account fluctuations on all length scales. The derivation of the leading correction ... More
Genetic Toggle Switch in the Absence of Cooperative Binding: Exact ResultsJun 18 2015Oct 22 2015We present an analytical treatment of a genetic switch model consisting of two mutually inhibiting genes operating without cooperative binding of the corresponding transcription factors. Previous studies have numerically shown that these systems can exhibit ... More
Local estimates for parabolic equations with nonlinear gradient termsNov 10 2014Nov 12 2014In this paper we deal with local estimates for parabolic problems in $\mathbb{R}^N$ with absorbing first order terms, whose model is $\{ {l} u_t- \Delta u +u |\nabla u|^q = f(t,x) \quad &{in}\, (0,T) \times \mathbb{R}^N\,, \\[1.5 ex] u(0,x)= u_0 (x) &box{in}\, ... More
Momentum distribution in the unitary Bose gas from first principlesApr 29 2016Nov 22 2016We consider a realistic bosonic N-particle model with unitary interactions relevant for Efimov physics. Using quantum Monte Carlo methods, we find that the critical temperature for Bose-Einstein condensation is decreased with respect to the ideal Bose ... More
Discrete groups without finite quotientsApr 03 2018We construct an infinite discrete subgroup of the isometry group of $\mathbb H^3$ with no finite quotients other than the trivial group.
Astrometric requirements for strong lensing time-delay cosmographyApr 24 2019Apr 29 2019The time delay between the arrival of photons of multiple images of time variable sources can be used to constrain absolute distances in the Universe (Refsdal 1964), and in turn obtain a direct estimate of the Hubble constant and other cosmological parameters. ... More
The Hamilton principle for fluid binary mixtures with two temperaturesMay 02 2009For binary mixtures of fluids without chemical reactions, but with components having different temperatures, the Hamilton principle of least action is able to produce the equation of motion for each component and a balance equation of the total heat exchange ... More
Quench dynamics of quantum spin models with flat bands of excitationsJun 25 2018We investigate the unitary evolution following a quantum quench in quantum spin models possessing a (nearly) flat band in the linear excitation spectrum. Inspired by the perspective offered by ensembles of individually trapped Rydberg atoms, we focus ... More
Three-dimensional counter-examples to the Nash problemMay 03 2012Mar 13 2013The Nash problem asks about the existence of a correspondence between families of arcs through singularities of complex varieties and certain types of divisorial valuations. It has been positively settled in dimension 2 by Fern\'andez de Bobadilla and ... More
Obstructions to special Lagrangian desingularizations and the Lagrangian prescribed boundary problemSep 13 2006Apr 22 2009We exhibit infinitely many, explicit special Lagrangian isolated singularities that admit no asymptotically conical special Lagrangian smoothings. The existence/ nonexistence of such smoothings is an important component of the current efforts to understand ... More
Geometric formalities along the Chern-Ricci flowJun 04 2019In this paper, we study how the notions of geometric formality according to Kotschick and other geometric formalities adapted to the Hermitian setting evolve under the action of the Chern-Ricci flow on class VII surfaces, including Hopf and Inoue surfaces, ... More
Killed Rough Super-Brownian MotionJun 26 2019This note extends the results in [8] to construct the rough super-Brownian motion on finite volume with Dirichlet boundary conditions. The backbone of this study is the convergence of discrete approximations of the parabolic Anderson model (PAM) on a ... More
On The Nature of the Glass CrossoverApr 23 2015Stochastic Beta Relaxation (SBR) is a model for the dynamics of glass- forming liquids close to the glass transition singularity of the idealized mode- coupling theory (MCT) that has been derived from generic MCT-like theories by applying dynamical field-theory ... More
Zero-Temperature Limit of the SUSY-breaking Complexity in Diluted Spin-Glass ModelsNov 29 2004We study the SUSY-breaking complexity of the Bethe Lattice Spin-Glass in the zero temperature limit. We consider both the Gaussian and the bimodal distribution of the coupling constants. For $J_{ij}=\pm 1$ the SUSY breaking theory yields fields distributions ... More
Critical Dynamics in Glassy SystemsMay 15 2012Dec 13 2012Critical dynamics in various glass models including those described by mode coupling theory is described by scale-invariant dynamical equations with a single non-universal quantity, i.e. the so-called parameter exponent that determines all the dynamical ... More
Universality and Deviations in Disordered SystemsJan 08 2009We compute the probability of positive large deviations of the free energy per spin in mean-field Spin-Glass models. The probability vanishes in the thermodynamic limit as $P(\Delta f) \propto \exp[-N^2 L_2(\Delta f)]$. For the Sherrington-Kirkpatrick ... More
Dirty-boson physics with magnetic insulatorsMay 06 2013We review recent theoretical and experimental e?orts aimed at the investigation of the physics of interacting disordered bosons (so-called dirty bosons) in the context of quantum magnetism. The physics of dirty bosons is relevant to a wide variety of ... More
Momentum distribution in the unitary Bose gas from first principlesApr 29 2016Ultracold atomic gases have over the last decades boosted the understanding of quantum physics in the whole range from weak interactions to the infinite-interaction unitary limit. The latter has lead to a revival of the celebrated Efimov effect, that ... More
Analytical solutions for the dynamics of two trapped interacting ultracold atomsApr 27 2006We discuss exact solutions of the Schroedinger equation for the system of two ultracold atoms confined in an axially symmetric harmonic potential. We investigate different geometries of the trapping potential, in particular we study the properties of ... More
The X-ray flux and spectral variability of EMSS AGNSep 17 1997Fifteen ROSAT PSPC observations available in the public archive are analyzed in order to study time and spectral variability of the 12 EMSS AGN detected by ROSAT with more than 2000 net counts. Time variability was investigated on 13 different time scales, ... More
The effect of reionization on the CMB-density correlationJun 02 2007In this paper we show how the rescattering of CMB photons after cosmic reionization can give a significant linear contribution to the temperature-matter cross-correlation measurements. These anisotropies, which arise via a late time Doppler effect, are ... More
Linear Stability and the Braess Paradox in Coupled Oscillators Networks and Electric Power GridsMay 29 2015Apr 05 2016We investigate the influence that adding a new coupling has on the linear stability of the synchronous state in coupled oscillators networks. Using a simple model we show that, depending on its location, the new coupling can lead to enhanced or reduced ... More
Ground states of self-gravitating elastic bodiesAug 08 2012Oct 08 2012The existence of static, self-gravitating elastic bodies in the non-linear theory of elasticity is established. Equilibrium configurations of self-gravitating elastic bodies close to the reference configuration have been constructed in [6] using the implicit ... More
The internal structure and formation of early-type galaxies: the gravitational--lens system MG2016+112 at z=1.004Feb 18 2002Apr 10 2002[Abridged] We combine our measurements of the velocity dispersion and the surface brightness profile of the lens galaxy D in the system MG2016+112 (z=1.004) with constraints from gravitational lensing to study its internal mass distribution. We find that: ... More
Performance Measures in Electric Power Networks under Line ContingenciesNov 28 2017Jul 24 2018Classes of performance measures expressed in terms of ${\cal H}_2$-norms have been recently introduced to quantify the response of coupled dynamical systems to external perturbations. So far, investigations of these performance measures have been restricted ... More
Real time estimation in local polynomial regression, with application to trend-cycle analysisJan 27 2009The paper focuses on the adaptation of local polynomial filters at the end of the sample period. We show that for real time estimation of signals (i.e., exactly at the boundary of the time support) we cannot rely on the automatic adaptation of the local ... More