Results for "Gian C. Gomez Cortes"

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Sliding Motions on SO(3), Sliding SubgroupsMay 14 2019We propose a sliding surface for systems on the Lie group $SO(3)\times \mathbb{R}^3$ . The sliding surface is shown to be a Lie subgroup. The reduced-order dynamics along the sliding subgroup have an almost globally asymptotically stable equilibrium. ... More
Large-$N$ Pion Scattering, Finite-Temperature Effects and the Relationship of the $f_{0}(500)$ with Chiral Symmetry RestorationApr 06 2016May 04 2016In this work, we review how the mass and the width of the $f_{0}(500)$ pole behave in a regime where temperature is below the critical chiral transition value. This is attained by considering a large-$N$ $O(N + 1)/O(N)$ invariant Non-Linear Sigma Model ... More
Large-$N$ pion scattering at finite temperature: the $f_0(500)$ and chiral restorationOct 30 2015May 13 2016We consider the $O(N+1)/O(N)$ Non-Linear Sigma Model for large $N$ as an effective theory for low-energy QCD at finite temperature $T$, in the chiral limit. At $T=0$ this formulation provides a good description of scattering data in the scalar channel ... More
On the approximation of the probability density function of the randomized non-autonomous complete linear differential equationFeb 08 2018In this paper we study the randomized non-autonomous complete linear differential equation. The diffusion coefficient and the source term in the differential equation are assumed to be stochastic processes and the initial condition is treated as a random ... More
On the approximation of the probability density function of the randomized heat equationFeb 08 2018In this paper we study the randomized heat equation with homogeneous boundary conditions. The diffusion coeffcient is assumed to be a random variable and the initial condition is treated as a stochastic process. The solution of this randomized partial ... More
Chiral Symmetry restoration from the hadronic regimeNov 22 2016We discuss recent advances on QCD chiral symmetry restoration at finite temperature, within the theoretical framework of Effective Theories. $U(3)$ Ward Identities are derived between pseudoscalar susceptibilities and quark condensates, allowing to explain ... More
On the integrability of N=2 supersymmetric massive theoriesDec 03 1993Dec 09 1993In this paper we propose a criteria to establish the integrability of N=2 supersymmetric massive theories.The basic data required are the vacua and the spectrum of Bogomolnyi solitons, which can be neatly encoded in a graph (nodes=vacua and links= Bogomolnyi ... More
Non-Critical Confining Strings and the Renormalization GroupFeb 01 1999Mar 01 1999String vacua for non critical strings satisfying the requirements of Zig-Zag invariance are constructed. The Liouville mode is shown to play the r\^ole of scale in the Renormalization Group operation. Differences and similarities with the D-brane near ... More
MSSM with Yukawa Quasi-UnificationMar 12 2003Apr 11 2003We consider the constrained minimal supersymmetric standard model which emerges from one theory with a small deviation from Yukawa unification which is adequate for $\mu>0$. We show that this model possesses a wide and natural range of parameters which ... More
Yukawa Quasi-Unification and Neutralino Relic DensityMar 12 2003The construction of a Supersymmetric Grand Unified Model based on the Pati-Salam gauge group is briefly reviewed and the low energy consequences of the derived asymptotic Yukawa quasi-unification conditions are examined. In the framework of the resulting ... More
On the Ages of Exoplanet Host StarsOct 04 2005We obtained spectra, covering the CaII H and K region, for 49 exoplanet host (EH) stars, observable from the southern hemisphere. We measured the chromospheric activity index, Rhk. We compiled previously published values of this index for the observed ... More
A new construction of homogeneous quaternionic manifolds and related geometric structuresAug 13 1999Let V be the pseudo-Euclidean vector space of signature (p,q), p>2 and W a module over the even Clifford algebra Cl^0 (V). A homogeneous quaternionic manifold (M,Q) is constructed for any spin(V)-equivariant linear map \Pi : \wedge^2 W \to V. If the skew ... More
On Yukawa quasi-unification with mu<0Jan 10 2003Although recent data on the muon anomalous magnetic moment strongly disfavor the constrained minimal supersymmetric standard model with mu<0, they cannot exclude it because of theoretical ambiguities. We consider this model supplemented by a Yukawa quasi-unification ... More
Supersymmetric Cold Dark Matter with Yukawa UnificationJul 07 1999May 08 2000The cosmological relic density of the lightest supersymmetric particle of the minimal supersymmetric standard model is calculated under the assumption of gauge and Yukawa coupling unification. We employ radiative electroweak breaking with universal boundary ... More
q--Magnetism at roots of unityJun 01 1992We study the thermodynamic properties of a family of integrable 1D spin chain hamiltonians associated with quantum groups at roots of unity. These hamiltonians depend for each primitive root of unit on a parameter $s$ which plays the role of a continuous ... More
On linearly related sequences of difference derivatives of discrete orthogonal polynomialsFeb 04 2014Jul 01 2014Let D_v the difference operator and q-difference operators defined by D_\omega p(x) = \frac{p(x+\omega)-p(x)}{\omega} and D_q p(x) = \frac{p(qx)-p(x)}{(q-1)x}, respectively. Let U and V be two moment regular linear functionals and let (P_n)_n and Q_n)_n ... More
A Survey of Lagrangian Mechanics and Control on Lie algebroids and groupoidsNov 03 2005In this survey, we present a geometric description of Lagrangian and Hamiltonian Mechanics on Lie algebroids. The flexibility of the Lie algebroid formalism allows us to analyze systems subject to nonholonomic constraints, mechanical control systems, ... More
Yukawa Unification, b --> s gamma and Bino-Stau CoannihilationApr 04 2000Jun 18 2000The minimal supersymmetric standard model with universal boundary conditions and "asymptotic" Yukawa unification is considered. The full one-loop effective potential for radiative electroweak symmetry breaking as well as the one-loop corrections to the ... More
Quantum critical scaling and holographic bound for transport coefficients near Lifshitz pointsJul 12 2019The transport behavior of strongly anisotropic systems is significantly richer compared to isotropic ones. The most dramatic spatial anisotropy at a critical point occurs at a Lifshitz transition. The present study uses scaling arguments and the gauge ... More
3D MHD Modeling of the Gaseous Structure of the Galaxy: Description of the SimulationsJul 19 2004The extra stiffness that the magnetic field adds to the ISM changes the way it reacts to the presence of a spiral perturbation. At intermediate to high z, the gas shoots up before the arm, flows over, and falls behind it, as it approaches the next arm. ... More
Analytical Expressions for Spiral Arm Gravitational Potential and DensityJul 29 2002When modeling the three-dimensional hydrodynamics of interstellar material rotating in a galactic gravitational potential, it is useful to have an analytic expression for gravitational perturbations due to stellar spiral arms. We present such an expression ... More
Unassisted Quantitative Evaluation Of Despeckling FiltersApr 19 2017SAR (Synthetic Aperture Radar) imaging plays a central role in Remote Sensing due to, among other important features, its ability to provide high-resolution, day-and-night and almost weather-independent images. SAR images are affected from a granular ... More
Machine learning applied to quantum synchronization-assisted probingJan 16 2019A probing scheme is considered with an accessible and controllable qubit, used to probe an out-of equilibrium system consisting of a second qubit interacting with an environment. Quantum spontaneous synchronization between the probe and the system emerges ... More
Quantum critical scaling and holographic bound for transport coefficients near Lifshitz pointsJul 12 2019Jul 30 2019The transport behavior of strongly anisotropic systems is significantly richer compared to isotropic ones. The most dramatic spatial anisotropy at a critical point occurs at a Lifshitz transition. The present study uses scaling arguments and the gauge-gravity ... More
TextTopicNet - Self-Supervised Learning of Visual Features Through Embedding Images on Semantic Text SpacesJul 04 2018The immense success of deep learning based methods in computer vision heavily relies on large scale training datasets. These richly annotated datasets help the network learn discriminative visual features. Collecting and annotating such datasets requires ... More
The Integrable Bootstrap Program at Large N and its Applications in Gauge TheoryOct 23 2013Oct 29 2013We present results for the large-$N$ limit of the (1+1)-dimensional principal chiral sigma model. This is an asymptotically-free $N\times N$ matrix-valued field with massive excitations. All the form factors and the exact correlation functions of the ... More
Cooperative data-driven distributionally robust optimizationNov 13 2017Dec 16 2018This paper studies a class of multiagent stochastic optimization problems where the objective is to minimize the expected value of a function which depends on a random variable. The probability distribution of the random variable is unknown to the agents, ... More
The seven most massive clumps in W43-Main as seen by ALMA: Dynamical equilibrium and Magnetic FieldsJul 30 2019Here we present new ALMA observations of polarized dust emission from six of the most massive clumps in W43-Main. The clumps MM2, MM3, MM4, MM6, MM7, and MM8, have been resolved into two populations of fragmented filaments. From these two populations ... More
Inflationary scalar spectrum in loop quantum cosmologyJul 14 2006Jan 18 2007In the context of loop quantum cosmology, we consider an inflationary era driven by a canonical scalar field and occurring in the semiclassical regime, where spacetime is a continuum but quantum gravitational effects are important. The spectral amplitude ... More
Distributed bilayered control for transient frequency safety and system stability in power gridsJun 07 2019This paper considers power networks governed by swing nonlinear dynamics and subject to disturbances. We develop a bilayered control strategy for a subset of buses that simultaneously guarantees transient frequency safety of each individual bus and asymptotic ... More
Coordination and geometric optimization via distributed dynamical systemsMay 29 2003This paper discusses dynamical systems for disk-covering and sphere-packing problems. We present facility location functions from geometric optimization and characterize their differentiable properties. We design and analyze a collection of distributed ... More
Transient frequency control with regional cooperation for power networksSep 15 2018This paper proposes a centralized and a distributed sub-optimal control strategy to maintain in safe regions the real-time transient frequencies of a given collection of buses, and simultaneously preserve asymptotic stability of the entire network. In ... More
Mechanical control systems on Lie algebroidsFeb 26 2004This paper considers control systems defined on Lie algebroids. After deriving basic controllability tests for general control systems, we specialize our discussion to the class of mechanical control systems on Lie algebroids. This class of systems includes ... More
Pointwise estimates of weighted Bergman kernels in several complex variablesFeb 03 2015We prove new pointwise bounds for weighted Bergman kernels in $\mathbb{C}^n$, whenever a coercivity condition is satisfied by the associated weighted Kohn Laplacian on $(0,1)$-forms. Our results extend the ones obtained in $\mathbb{C}$ by Christ. Our ... More
Monodromy of constant mean curvature surface in hyperbolic spaceNov 20 2006We give a global version of the Bryant representation of surfaces of constant mean curvature one (cmc-1) in hyperbolic space. This allows to set the associated non-abelian period problem in the framework of flat unitary vector bundles on Riemann surfaces. ... More
Monogamy properties of quantum and classical correlationsSep 08 2011Nov 11 2011In contrast with entanglement, as measured by concurrence, in general, quantum discord does not possess the property of monogamy, that is, there is no tradeoff between the quantum discord shared by a pair of subsystems and the quantum discord that both ... More
Spontaneous PT symmetry breaking and quantum phase transitions in dimerized spin chainsAug 24 2010The occurrence of parity-time reversal ($\mathcal{PT}$) symmetry breaking is discussed in a non-Hermitian spin chain. The Hermiticity of the model is broken by the presence of an alternating, imaginary, transverse magnetic field. A full real spectrum, ... More
Positive Nonlinear Dynamical Group Uniting Quantum Mechanics and ThermodynamicsDec 27 2006We discuss and motivate the form of the generator of a nonlinear quantum dynamical group 'designed' so as to accomplish a unification of quantum mechanics (QM) and thermodynamics. We call this nonrelativistic theory Quantum Thermodynamics (QT). Its conceptual ... More
On noncompactness of the $\overline\partial$-Neumann problem on pseudoconvex domains in $\mathbb{C}^3$May 03 2017May 04 2017In this paper we deal with the following question: is it true that any bounded smooth pseudoconvex domain in $\mathbb{C}^n$ whose boundary contains a $q$-dimensional complex manifold $M$ necessarily has a noncompact $\overline\partial$-Neumann operator ... More
Coercivity of weighted Kohn Laplacians: the case of model monomial weights in $\mathbb{C}^2$Feb 09 2015Feb 10 2015The weighted Kohn Laplacian $\Box_\varphi$ is a natural second order elliptic operator associated to a weight $\varphi:\mathbb{C}^n\rightarrow\mathbb{R}$ and acting on $(0,1)$-forms, which plays a key role in several questions of complex analysis. We ... More
Analyzing spiral structure in a galactic disk with a gaseous componentOct 17 2013Using GADGET2, we performed an SPH+N-body simulation of a galactic disk with stellar and gas particles. This simulation allows to compare the spiral structure in the different disk components. Also, we performed a simulation without gaseous component ... More
Quintessential Kination and Thermal Production of SUSY e-WIMPsSep 11 2008The impact of a kination-dominated phase generated by a quintessential exponential model on the thermal abundance of Supersymmetric (SUSY) extremely Weekly Interacting Massive Particles (e-WIMPs) is investigated. For values of the quintessential energy-density ... More
Characterization of Local Configuration Controllability for a Class of Mechanical SystemsSep 08 2000We investigate local configuration controllability for mechanical control systems within the affine connection formalism. Extending the work by Lewis for the single-input case, we are able to characterize local configuration controllability for systems ... More
Abelian simply transitive affine groups of symplectic typeMay 03 2001Nov 28 2002We construct a model space $C(\gsp(\bR^{2n}))$ for the variety of Abelian simply transitive groups of affine transformations of type ${\rm Sp}(\bR^{2n})$. The model is stratified and its principal stratum is a Zariski-open subbundle of a natural vector ... More
Distributed Transient Frequency Control for Power Networks with Stability and Performance GuaranteesSep 15 2018This paper proposes a distributed strategy regulated on a subset of individual buses in a power network described by the swing equations to achieve transient frequency control while preserving asymptotic stability. Transient frequency control refers to ... More
Double-layered distributed transient frequency control with regional coordination for power networksSep 27 2018This paper proposes a control strategy for power systems with a two-layer structure that achieves global stabilization and, at the same time, delimits the transient frequencies of targeted buses to a desired safe interval. The first layer is a model predictive ... More
Distributed transient frequency control in power networksSep 15 2018Modern power networks face increasing challenges in controlling their transient frequency behavior at acceptable levels due to low inertia and highly-dynamic units. This paper presents a distributed control strategy regulated on a subset of buses in a ... More
Model predictive control for transient frequency regulation of power networksJan 22 2019This paper introduces a control strategy to simultaneously achieve asymptotic stabilization and transient frequency regulation of power networks. The control command is generated by iteratively solving an open-loop control cost minimization problem with ... More
Spectroscopic metallicities of Vega-like starsMay 26 2008Aims: To determine the metallicities of 113 Southern Hemisphere Vega-like candidate stars in relation to the Exoplanet host group and field stars. Methods: We applied two spectroscopic methods of abundance determinations: equivalent width measurements ... More
Modeling the 3C 120 Radio Jet from 1 to 30 MilliarcsecondsOct 29 2004The predicted spatial development of helical structures along an expanding jet are used to model observed structures and motions in the 3C 120 jet. Proper motions of helical components associated with the pattern and of other components that move through ... More
A Re-examination of the Distribution of Galactic Free ElectronsMay 23 2001We present a list of 109 pulsars with independent distance information compiled from the literature. Since the compilation of Frail & Weisberg, there are 35 pulsars with new distance estimate and 25 pulsars for which the distance or distance uncertainty ... More
Electronic transport in quantum cascade structuresOct 13 2006The transport in complex multiple quantum well heterostructures is theoretically described. The model is focused on quantum cascade detectors, which represent an exciting challenge due to the complexity of the structure containing 7 or 8 quantum wells ... More
Near-Field cosmology with RR Lyrae variable stars: A first view of substructure in the southern skyMar 23 2016We present an update of a spectroscopic follow-up survey at low-resolution of a large number of RR Lyrae halo overdensity candidates found in the southern sky. The substructure candidates were identified in the RR Lyrae catalog of Torrealba et al. (2015) ... More
On Future High-Energy CollidersFeb 21 2019Feb 25 2019An outline of the physics reasons to pursue a future programme in high-energy colliders is presented.
The Dawn of the Post-Naturalness EraOct 18 2017In an imaginary conversation with Guido Altarelli, I express my views on the status of particle physics beyond the Standard Model and its future prospects.
Pomeron-Odderon Interactions: A Functional RG Flow AnalysisNov 22 2016Nov 25 2016In the quest for an effective field theory which could help to understand some non perturbative feature of the QCD in the Regge limit, we consider a Reggeon Field Theory (RFT) for both Pomeron and Odderon interactions and perform an analysys of the critical ... More
The fourth law of thermodynamics: steepest entropy ascentAug 15 2019When thermodynamics is understood as the science (or art) of constructing effective models of natural phenomena by choosing a minimal level of description capable of capturing the essential features of the physical reality of interest, the scientific ... More
Correlation Functions of the SU(infinity) Principal Chiral ModelJun 08 2013Jul 20 2013We obtain exact matrix elements of physical operators of the (1+1)-dimensional nonlinear sigma model of an SU(N)-valued bare field, in the 't Hooft limit N goes to infinity. Specifically, all the form factors of the Noether current and the stress-energy-momentum ... More
Classification of stationary compact homogeneous special pseudo Kähler manifolds of semisimple groupsNov 11 1997May 26 1999The variation of Hodge structure of a Calabi-Yau 3-fold induces a canonical K\"ahler metric on its Kuranishi moduli space, known as the Weil-Petersson metric. Similarly, special pseudo K\"ahler manifolds correspond to certain (abstract) variations of ... More
On the detectability of transiting planets orbiting white dwarfs using LSSTOct 01 2018White dwarfs are one of the few types of stellar objects for which we know almost nothing about the possible existence of companion planets. Recent evidence for metal contaminated atmospheres, circumstellar debris disks and transiting planetary debris ... More
Forecasting Mobile Traffic with Spatiotemporal correlation using Deep RegressionJul 25 2019The concept of mobility prediction represents one of the key enablers for an efficient management of future cellular networks, which tend to be progressively more elaborate and dense due to the aggregation of multiple technologies. In this letter we aim ... More
Reliable Prediction Errors for Deep Neural Networks Using Test-Time DropoutApr 12 2019While the use of deep learning in drug discovery is gaining increasing attention, the lack of methods to compute reliable errors in prediction for Neural Networks prevents their application to guide decision making in domains where identifying unreliable ... More
Machine learning algorithms based on generalized Gibbs ensemblesApr 10 2018Dec 01 2018Machine learning algorithms often take inspiration from established results and knowledge from statistical physics. A prototypical example is the Boltzmann machine algorithm for supervised learning, which utilizes knowledge of classical thermal partition ... More
Hamiltonian theory of constrained impulsive motionJan 27 2004This paper considers systems subject to nonholonomic constraints which are not uniform on the whole configuration manifold. When the constraints change, the system undergoes a transition in order to comply with the new imposed conditions. Building on ... More
Exploration of Micro-VCSEL Ultra-low Biasing Scheme for Pulse GenerationNov 12 2018Nov 16 2018The generation of optical pulses at ultra low bias level, thus low energy cost, is explored in a commercial microcavity semiconductor laser in view of testing the principle of energy efficient information encoding in potential integrated schemes. Sequences ... More
Cover art: issues in the metric-guided and metric-less placement of random and stochastic template banksSep 03 2009Jan 14 2010The efficient placement of signal templates in source-parameter space is a crucial requisite for exhaustive matched-filtering searches of modeled gravitational-wave sources. Unfortunately, the current placement algorithms based on regular parameter-space ... More
Topological properties of chains of magnetic impurities on a superconducting substrate: Interplay between the Shiba band and ferromagnetic wire limitsSep 11 2017Dec 12 2017We consider a one-dimensional system combining local magnetic moments and a delocalized metallic band on top of a superconducting substrate. This system can describe a chain of magnetic impurities with both localized polarized orbitals and delocalized ... More
Covariant and single-field effective action with the background-field formalismJul 11 2016Sep 11 2017In the context of scalar quantum field theory we introduce a class of generically nonlinear quantum-background splits for which the splitting Ward identity, encoding the single field dependence in the effective action, can be solved exactly. We show that ... More
Hurwitz spaces and liftings to the Valentiner groupJul 11 2016Aug 05 2016We study the components of the Hurwitz scheme of ramified coverings of $\mathbb{P}^1$ with monodromy given by the alternating group $A_6$ and elements in the conjugacy class of product of two disjoint cycles. In order to detect the connected components ... More
Novel Bounds for the Normalized Laplacian Estrada and Normalized Energy Index of GraphsAug 03 2015Jul 04 2016For a simple and connected graph, several lower and upper bounds of graph invariants expressed in terms of the eigenvalues of the normalized Laplacian matrix have been proposed in literature. In this paper, through a unified approach based on majorization ... More
Covariant and background independent functional RG flow for the effective average actionJul 24 2016Nov 21 2016We extend our prescription for the construction of a covariant and background-independent effective action for scalar quantum field theories to the case where momentum modes below a certain scale are suppressed by the presence of an infrared regulator. ... More
A Selection Principle for the Sharp Quantitative Isoperimetric InequalityJul 22 2010We introduce a new variational method for the study of stability in the isoperimetric inequality. The method is quite general as it relies on a penalization technique combined with the regularity theory for quasiminimizers of the perimeter. Two applications ... More
Two-step approach to scheduling quantum circuitsJul 31 2017May 14 2018As the effort to scale up existing quantum hardware proceeds, it becomes necessary to schedule quantum gates in a way that minimizes the number of operations. There are three constraints that have to be satisfied: the order or dependency of the quantum ... More
Synchronous Characterization of Semiconductor Microcavity Laser BeamJun 05 2015We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show ... More
Massey Products and Fujita decompositions on fibrations of curvesOct 08 2017Dec 11 2018Let $f:S\to B$ be a fibration of curves and let $f_\ast\omega_{S/B}=\cU\oplus \cA$ be the second Fujita decomposition of $f.$ In this paper we study a kind of Massey products, which are defined as infinitesimal invariants by the cohomology of a curve, ... More
Infinitesimal invariant and vector bundlesDec 28 2006We study the Saito-Ikeda infinitesimal invariant of the ccle defined by curves in their jacobians using rank (k+1) vector bundles and we give a criterion for which the higher cycle class map is not trivial. When k=2, this turns out to be strictly linked ... More
Constraints on extra-dimensional theories from virtual-graviton exchangeJan 27 2003We study the effective interactions induced by loops of extra-dimensional gravitons and show the special role of a specific dimension-6 four-fermion operator, product of two flavour-universal axial currents. By introducing an ultraviolet cut-off, we compare ... More
Monodromy of Projective CurvesDec 19 2003Jan 21 2004The uniform position principle states that, given an irreducible nondegenerate curve C in the projective r-space $P^r$, a general (r-2)-plane L is uniform, that is, projection from L induces a rational map from C to $P^1$ whose monodromy group is the ... More
Search of scaling solutions in scalar-tensor gravityJan 05 2015Apr 28 2015We write new functional renormalization group equations for a scalar nonminimally coupled to gravity. Thanks to the choice of the parametrization and of the gauge fixing they are simpler than older equations and avoid some of the difficulties that were ... More
Gauge invariant backreaction in general single field models of inflationApr 08 2013Jul 25 2013In a general single field inflationary model we consider the effects of long wavelength scalar fluctuations on the effective expansion rate and equation of state seen by a class of free falling observers, using a physical gauge invariant formulation. ... More
Genuine correlations in finite-size spin systemsJun 08 2012Genuine multipartite correlations in finite-size XY chains are studied as a function of the applied external magnetic field. We find that, for low temperatures, multipartite correlations are sensitive to the parity change in the Hamiltonian ground state, ... More
A remark on an estimate by MinamiApr 14 2006In the context of the Anderson model, Minami proved a Wegner type bound on the expectation of 2 by 2 determinant of Green's functions. We generalize it so as to allow for a magnetic field, as well as to determinants of higher order.
Directed clustering in weighted networks: a new perspectiveJun 19 2017In this paper, we consider the problem of assessing local clustering in complex networks. Various definitions for this measure have been proposed for the cases of networks having weighted edges, but less attention has been paid to both weighted and directed ... More
Uncovering novel phase structures in $\Box^k$ scalar theories with the renormalization groupNov 23 2017Mar 08 2018We present a detailed version of our recent work on the renormalization group approach to multicritical scalar theories with higher derivative kinetic term of the form $\phi(-\Box)^k\phi$ and upper critical dimension $d_c = 2nk/(n-1)$. Depending on whether ... More
Parametrization of rational maps on a variety of general type, and the finiteness theoremMar 10 2012In a previous paper, we provided some update in the treatment of the finiteness theorem for rational maps of finite degree from a fixed variety to varieties of general type. In the present paper we present another improvement, introducing the natural ... More
Algebraic functions with even monodromyDec 01 2003Let $X$ be a compact Riemann surface of genus $g$ and $d\geq 12g+4$ be an integer. We show that $X$ admits meromorphic functions with monodromy group equal to the alternating group $A_d.$
New Bounds for the Sum of Powers of Normalized Laplacian Eigenvalues of GraphsAug 03 2015For a simple and connected graph, a new graph invariant $s_{\alpha}^{*}(G)$, defined as the sum of powers of the eigenvalues of the normalized Laplacian matrix, has been introduced by Bozkurt and Bozkurt in [7]. Lower and upper bounds have been proposed ... More
Vanishing cohomology on a double cover of a very general hyper surfaceJul 07 2018In this paper, we study the irreducibility of the monodromy action on the anti-invariant part of the vanishing cohomology on the double cover of a very general element in an ample hypersurface of a complex smooth projective variety branched at an ample ... More
On the Cheeger sets in strips and non-convex domainsSep 04 2014In this paper we consider the Cheeger problem for non-convex domains, with a particular interest in the case of planar strips, which have been extensively studied in recent years. Our main results are an estimate on the Cheeger constant of strips, which ... More
Dynamical Mass Reduction in the Massive Yang-Mills Spectrum in 1+1 dimensionsMar 02 2014Mar 14 2014The (1+1)-dimensional SU}(N) Yang-Mills Lagrangian, with bare mass M, and gauge coupling e, naively describes gluons of mass M. In fact, renormalization forces M to infinity. The system is in a confined phase, instead of a Higgs phase. The spectrum of ... More
A note on spaces of symmetric matricesFeb 09 2007We calculate the maximal dimension of linear spaces of symmetric and hermitian matrices with given high rank, generalizing a well-known result of Adams {\em et al.}
On the k-normality of some projective manifoldsOct 29 1997A long standing conjecture, known to us as the Eisenbud Goto conjecture, states that an n-dimensional variety embedded with degree $d$ in the $N$- dimensional projective space is $(d-(N-n)+1)$-regular in the sense of Castelnuovo-Mumford. In this work ... More
Improved convergence theorems for bubble clusters. II. The three-dimensional caseMay 25 2015Given a sequence $\{\mathcal{E}_{k}\}_{k}$ of almost-minimizing clusters in $\mathbb{R}^3$ which converges in $L^{1}$ to a limit cluster $\mathcal{E}$ we prove the existence of $C^{1,\alpha}$-diffeomorphisms $f_k$ between $\partial\mathcal{E}$ and $\partial\mathcal{E}_k$ ... More
The background scale Ward identity in quantum gravityNov 21 2016Jan 11 2017We show that with suitable choices of parametrization, gauge fixing and cutoff, the anomalous variation of the effective action under global rescalings of the background metric is identical to the derivative with respect to the cutoff, i.e. to the beta ... More
Bounding robustness in complex networks under topological changes through majorization techniquesJun 21 2019Measuring robustness is a fundamental task for analyzing the structure of complex networks. Indeed, several approaches to capture the robustness properties of a network have been proposed. In this paper we focus on spectral graph theory where robustness ... More
On the geometry of the second fundamental form of the Torelli mapJul 26 2019In this paper we give a geometric interpretation of the second fundamental form of the period map of curves and we use it to improve the upper bounds on the dimension of a totally geodesic subvariety Y of A_g generically contained in the Torelli locus ... More
The Bulk-Edge Correspondence for Disordered Chiral ChainsJan 29 2018We study one-dimensional insulators obeying a chiral symmetry in the single-particle picture. The Fermi level is assumed to lie in a mobility gap. Topological indices are defined for infinite (bulk) or half-infinite (edge) systems, and it is shown that ... More
Multi-critical $\square^k$ scalar theories: A perturbative RG approach with $ε$-expansionAug 31 2017Feb 10 2018We employ perturbative RG and $\epsilon$-expansion to study multi-critical single-scalar field theories with higher derivative kinetic terms of the form $\phi(-\Box)^k\phi$. We focus on those with a $\mathbb{Z}_2$-symmetric critical point which are characterized ... More
Rigidity and trace properties of divergence-measure vector fieldsAug 04 2017Mar 05 2019We consider a $\varphi$-rigidity property for divergence-free vector fields in the Euclidean $n$-space, where $\varphi(t)$ is a non-negative convex function vanishing only at $t=0$. We show that this property is always satisfied in dimension $n=2$, while ... More
On dominant rational maps from products of curves to surfaces of general typeJun 20 2012Jun 11 2013In this paper we investigate the existence of generically finite dominant rational maps from products of curves to surfaces of general type. We prove that the product CxD of two distinct very general curves of genus g>6 and g'>1 does not admit dominant ... More