Results for "Edgar Dutra Zanotto"

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The failure of the Classical Nucleation Theory at low temperatures resolvedFeb 08 2019A relevant observation about crystal nucleation kinetics in glass-forming substances has been a matter of intense debate for several decades. The Classical Nucleation Theory (CNT) allegedly fails to describe the temperature dependence of the homogeneous ... More
Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillatorsSep 02 2015In this article we discuss a model describing key features concerning the lineshapes and the coherent absorption conditions in Fano-resonant dissipative coupled oscillators. The model treats on the same footing the weak and strong coupling regimes, and ... More
On killers of cable knots groupsOct 12 2016A killer of a group Gis an element that normally generates G. We show that the group of a cable knot contains infinitely many killers such that no two lie in the same automorphic orbit.
Fundamental limits on the losses of phase and amplitude optical actuatorsOct 08 2018Amplitude and phase are the basic properties of every wave phenomena; as long as optical waves are concerned, the ability to act on these variables is at the root of a wealth of switching devices. To quantify the performance of an optical switching device, ... More
Coherent perfect absorption in photonic structuresJun 01 2016The ability to drive a system with an external input is a fundamental aspect of light-matter interaction. The coherent perfect absorption (CPA) phenomenon extends to the general multibeam interference phenomenology the well known critical coupling concepts. ... More
Strong-Weak Coupling Duality in Quantum MechanicsSep 18 1996We present a strong-weak coupling duality for quantum mechanical potentials. Similarly to what happens in quantum field theory, it relates two problems with inverse couplings, leading to a mapping of the strong coupling regime into the weak one, giving ... More
Deformed solitons: The case of two coupled scalar fieldsMay 22 2007In this work, we present a general procedure, which is able to generate new exact solitonic models in 1+1 dimensions, from a known one, consisting of two coupled scalar fields. An interesting consequence of the method, is that of the appearing of nontrivial ... More
Rebuttal to Schmelzer and Tropin: Glass Transition, Crystallization of Glass-Forming Melts, and EntropyMar 20 2018In a recent article, Schmelzer and Tropin [Entropy 20 [2] 103 (2018)] presented an unfounded, confusing critique of several aspects of modern glass science. Relying on pre-Socratic Greek philosophy and state-of-the-art scientific understanding from the ... More
Mapping deformed hyperbolic potentials into nondeformed onesJan 18 2005In this work we introduce a mapping between the so called deformed hyperbolic potentials, which are presenting a continuous interest in the last few years, and the corresponding nondeformed ones. As a consequence, we conclude that these deformed potentials ... More
SPPAM - Statistical PreProcessing AlgorithMMar 11 2011Most machine learning tools work with a single table where each row is an instance and each column is an attribute. Each cell of the table contains an attribute value for an instance. This representation prevents one important form of learning, which ... More
Quantum propagator for some classes of three-dimensional three-body systemsMay 18 2007In this work we solve exactly a class of three-body propagators for the most general quadratic interactions in the coordinates, for arbitrary masses and couplings. This is done both for the constant as the time-dependent couplings and masses, by using ... More
General solutions for some classes of interacting two field kinksMay 21 2007In this work we present some classes of models whose the corresponding two coupled first-order nonlinear equations can be put into a linear form, and consequently be solved completely. In these cases the so-called trial orbit method is completely unnecessary. ... More
Photonic bands and defect modes in metallo-dielectric photonic crystal slabsMay 30 2016Photonic components based on structured metallic elements show great potential for device applications where field enhancement and confinement of the radiation on a subwavelength scale is required. In this paper we report a detailed study of a prototypical ... More
Saturation and bistability of defect-mode intersubband polaritonsMay 28 2016In this article we report about linear and nonlinear optical properties of intersubband cavity polariton samples, where the resonant photonic mode is a defect state in a metallo-dielectric photonic crystal slab. By tuning a single geometric parameter ... More
Physics with Single Photons plus Missing Energy Final States at D0May 29 2009Final state signatures of a single photon and missing transverse energy offer unique and powerful advantages in the search for new physics. This document presents the first observation of the Zgamma to nunu_bargamma process at the Tevatron Collider at ... More
Is the Basic Unit System a String?Oct 28 2000The main aim of this paper is to present an overview of the need of a new way of coping the fundamental equations of physics, see the references. Our main aim is to build a new metrics in which both time and space are included, but in some sort of minkowskian ... More
A general convex framework for multiple testing with prior informationMar 17 2016Using prior information may improve power in frequentist multiple testing. P-value weighting is a promising methodology where each test is conducted at a different level, using critical values based on independent prior data. However, existing methods ... More
Black hole microstates in AdSDec 21 2015We extend a recently derived higher-dimensional Cardy formula to include angular momenta, which we use to obtain the Bekensten-Hawking entropy of AdS black branes, compactified rotating branes, and large Schwarzschild/Kerr black holes. This is the natural ... More
Modular forms and a generalized Cardy formula in higher dimensionsAug 11 2015Nov 23 2016We derive a formula which applies to conformal field theories on a spatial torus and gives the asymptotic density of states solely in terms of the vacuum energy on a parallel plate geometry. The formula follows immediately from global scale and Lorentz ... More
First and second-order metal-insulator phase transitions and topological aspects of a Hubbard-Rashba systemOct 18 2016Oct 24 2016This paper considers a model consisting of a kinetic term, Rashba spin-orbit coupling and short-range Coulomb interaction at zero-temperature. The Coulomb interaction is decoupled by a mean-field approximation in the spin channel using field theory methods. ... More
FRW cosmologies and hyperscaling-violating geometries: higher curvature corrections, ultrametricity, Q-space/QFT duality, and a little string theoryAug 05 2013Apr 14 2014We analyze flat FRW cosmologies and hyperscaling-violating geometries by emphasizing the analytic continuation between them and their scale covariance. We exhibit two main calculations where this point of view is useful. First, based on the scale covariance, ... More
On sup-norm bounds part I: ramified Maaß newforms over number fieldsOct 01 2017We prove new upper bounds for the sup-norm of Hecke Maa{\ss} newforms on $GL(2)$ over a number field. Our newforms are more general than those considered in a recent paper by Blomer, Harcos, Maga, and Mili\`cevi\`c: we do not require square free level. ... More
Emergent gravity from Eguchi-Kawai reductionNov 13 2016Holographic theories with a local gravitational dual have a number of striking features. Here I argue that many of these features are controlled by the Eguchi-Kawai mechanism, which is proposed to be a hallmark of such holographic theories. Higher-spin ... More
High Mach-number Bondi--Hoyle--Lyttleton flow around a small accretorJan 05 2005In this paper, we discuss a two-dimensional numerical study of isothermal high Mach number Bondi--Hoyle--Lyttleton flow around a small accretor. The flow is found to be unstable at high Mach numbers, with the instability appearing even for a larger accretor. ... More
The distribution of the number of parts of $m$-ary partitions modulo $m$Feb 29 2016We investigate the number of parts modulo $m$ of $m$-ary partitions of a positive integer $n$. We prove that the number of parts is equidistributed modulo $m$ on a special subset of $m$-ary partitions. As consequences, we explain when the number of parts ... More
Emergent gravity from Eguchi-Kawai reductionNov 13 2016Nov 15 2016Holographic theories with a local gravitational dual have a number of striking features. Here I argue that many of these features are controlled by the Eguchi-Kawai mechanism, which is proposed to be a hallmark of such holographic theories. Higher-spin ... More
First and second-order metal-insulator phase transitions and topological aspects of a Hubbard-Rashba systemOct 18 2016This paper considers a model consisting of a kinetic term, Rashba spin-orbit coupling and short-range Coulomb interaction at zero-temperature. The Coulomb interaction is decoupled by a mean-field approximation in the spin channel using field theory methods. ... More
Gravitational Fields and The Basic Unit System conceptAug 22 1999This is the third one of three papers I have presented as an application of the Basic Unit System concept, a complex mathematical unit presented in The Basic Unit System concept and The Principle of Synergy. In this case this Bus concept is used as a ... More
On the size of p-adic Whittaker functionsOct 01 2017Dec 21 2018In this paper we tackle a question raised by N. Templier and A. Saha concerning the size of Whittaker new vectors appearing in infinite dimensional representations of GL(2) over non-archimedean fields. We derive precise bounds for such functions in all ... More
Permutation methods for factor analysis and PCAOct 02 2017Oct 06 2018Researchers often have datasets measuring features $x_{ij}$ of samples, such as test scores of students. In factor analysis and PCA, these features are thought to be influenced by unobserved factors, such as skills. Can we determine how many components ... More
Efficient Computation of Limit Spectra of Sample Covariance MatricesJul 07 2015Consider an $n \times p$ data matrix $X$ whose rows are independently sampled from a population with covariance $\Sigma$. When $n,p$ are both large, the eigenvalues of the sample covariance matrix are substantially different from those of the true covariance. ... More
Weighted mining of massive collections of $p$-values by convex optimizationMar 17 2016Jun 16 2017Researchers in data-rich disciplines---think of computational genomics and observational cosmology---often wish to mine large bodies of $p$-values looking for significant effects, while controlling the false discovery rate or family-wise error rate. Increasingly, ... More
Modular forms and a generalized Cardy formula in higher dimensionsAug 11 2015Apr 26 2016We derive a formula which applies to conformal field theories on a spatial torus and gives the asymptotic density of states solely in terms of the vacuum energy on a parallel plate geometry. The formula follows immediately from global scale and Lorentz ... More
Sharp detection in PCA under correlations: all eigenvalues matterFeb 22 2016Principal component analysis (PCA) is a widely used method for dimension reduction. In high dimensional data, the "signal" eigenvalues corresponding to weak principal components (PCs) do not necessarily separate from the bulk of the "noise" eigenvalues. ... More
Modular invariance on $S^1 \times S^3$ and circle fibrationsDec 15 2016Dec 10 2017I conjecture a high-temperature/low-temperature duality for conformal field theories defined on circle fibrations like $S^3$ and its lens space family. The duality is an exchange between the thermal circle and the fiber circle in the limit where both ... More
Emergent gravity from Eguchi-Kawai reductionNov 13 2016Dec 16 2016Holographic theories with a local gravitational dual have a number of striking features. Here I argue that many of these features are controlled by the Eguchi-Kawai mechanism, which is proposed to be a hallmark of such holographic theories. Higher-spin ... More
First and second-order metal-insulator phase transitions and topological aspects of a Hubbard-Rashba systemOct 18 2016Nov 07 2017This paper considers a model consisting of a kinetic term, Rashba spin-orbit coupling and short-range Coulomb interaction at zero-temperature. The Coulomb interaction is decoupled by a mean-field approximation in the spin channel using field theory methods. ... More
A Cardy formula for holographic hyperscaling-violating theoriesApr 08 2015Feb 10 2016We propose a formalism for counting the microstates of a class of three-dimensional black holes which are not asymptotically AdS. The formalism rests on the invariance of a dual field theory under a generalized modular transformation and is extended to ... More
Flexible Multiple Testing with the FACT AlgorithmJun 26 2018Modern high-throughput science often leads to multiple testing problems: researchers test many hypotheses, wishing to find the significant discoveries. The development of flexible multiple testing methods is thus a central problem in statistics. In this ... More
Yet another $GL_2$ subconvexity resultMay 02 2018In this paper we establish a very flexible and explicit Voronoi summation formula. This is then used to prove an almost Weyl strength subconvexity result for automorphic $L$-functions of degree two in the depth aspect. That is, looking at twists by characters ... More
Threads and Or-Parallelism UnifiedJul 26 2010One of the main advantages of Logic Programming (LP) is that it provides an excellent framework for the parallel execution of programs. In this work we investigate novel techniques to efficiently exploit parallelism from real-world applications in low ... More
Approximating the maximum of a polynomial over a polytope: Handelman decomposition and continuous generating functionsJan 16 2016Jun 25 2016We investigate a way to approximate the maximum of a polynomial over a polytopal region by using Handelman's polynomial decomposition and continuous multivariate generating functions. The maximization problem is NP-hard, but our approximation methods ... More
Class of self-dual models in three dimensionsFeb 14 2000In the present paper we introduce a hierarquical class of self-dual models in three dimensions, inspired in the original self-dual theory of Towsend-Pilch-Nieuwenhuizen. The basic strategy is to explore the powerful property of the duality transformations ... More
Accelerating Recommender Systems using GPUsNov 08 2015We describe GPU implementations of the matrix recommender algorithms CCD++ and ALS. We compare the processing time and predictive ability of the GPU implementations with existing multi-core versions of the same algorithms. Results on the GPU are better ... More
Free Relativistic Anyons with Canonical Spin AlgebraNov 10 1994Dec 01 1994We discuss a relativistic free particle with fractional spin in 2+1 dimensions, where the dual spin components satisfy the canonical angular momentum algebra $\left\{ S_\mu , S_\nu \right\}\,=\,\epsilon_{\mu \nu \gamma}S^\gamma $. It is shown that it ... More
Multiflavor SolderingDec 22 2007In two dimensions the simple addition of two chiral bosons of opposite chiralities does not lead to a full massless scalar field. Similarly, in three dimensions the addition of two Maxwell-Chern-Simons fields of opposite helicities $\pm 1$ will not produce ... More
Comment on ``Anyon in an External Eletromagnetic Field: Hamiltonian and Lagrangian Formulations''Feb 09 1994We comment on a recent paper by Chaichian et al. (Phys.Rev.Lett. 71(1993)3405).
Restrictions over two-dimensional gauge models with Thirring-like interactionDec 22 2007Some years ago, it was shown how fermion self-interacting terms of the Thirring-type impact the usual structure of massless two-dimensional gauge theories [1]. In that work only the cases of pure vector and pure chiral gauge couplings have been considered ... More
A Simple Action for a Free AnyonApr 16 1997By studying classical realizations of the sl(2,R) algebra in a two dimensional phase space $(q,\pi)$, we have derived a continuous family of new actions for free anyons in 2+1 dimensions. For the case of light-like spin vector $(S_\mu S^\mu =0)$, the ... More
Quantization of Maxwell-Chern-Simons-Podolsky TheoryMar 28 1994We quantize a generalized electromagnetism in 2 + 1 dimensions which contains a higher-order derivative term by using Dirac's method. By introducing auxiliary fields we transform the original theory in a lower-order derivative one which can be treated ... More
Driven tabu search: a quantum inherent optimisationAug 25 2018Quantum computers are different from binary digital electronic computers based on transistors. Common digital computing encodes the data into binary digits (bits), each of which is always in one of two definite states (0 or 1), quantum computation uses ... More
Application of Generalized Fokker-Planck Theory To Electron And Photon Transport In TissueDec 09 2009We study a deterministic method for particle transport in tissue in selected medical applications. Generalized Fokker-Planck (GFP) theory has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where ... More
Bound on induced gravitational wave background from primordial black holesNov 03 2009Dec 22 2009The today's energy density of the induced (second order) gravitational wave background in the frequency region $\sim 10^{-3} - 10^3$ Hz is constrained using the existing limits on primordial black hole production in the early Universe. It is shown, in ... More
Constraints on power spectrum of density fluctuations from PBH evaporationsDec 21 2006We calculate neutrino and photon energy spectra in extragalactic space from evaporation of primordial black holes, assuming that the power spectrum of primordial density fluctuations has a strong bump in the region of small scales. The constraints on ... More
Quantum walks on graphs and quantum scattering theoryMar 08 2004We discuss a particular kind of quantum walk on a general graph. We affix two semi-infinite lines to a general finite graph, which we call tails. On the tails, the particle making the walk simply advances one unit at each time step, so that its behavior ... More
Sparse Tensor Algebra as a Parallel Programming ModelNov 30 2015Dense and sparse tensors allow the representation of most bulk data structures in computational science applications. We show that sparse tensor algebra can also be used to express many of the transformations on these datasets, especially those which ... More
Analysis of Free Will and Determinism in PhysicsJun 27 2014It is considered the study of determinism in the theories of physics. Based on fundamental postulates of physics, it is proved that the evolution of the universe is univocally determined, proving ultimately that free will does not exist. In addition, ... More
Axion inflation with gauge field production and primordial black holesDec 28 2013Oct 19 2014We study the process of primordial black hole (PBH) formation at the beginning of radiation era for the cosmological scenario in which the inflaton is a pseudo-Nambu-Goldstone boson (axion) and there is a coupling of the inflaton with some gauge field. ... More
Spectral data and solvent theory for regular matrix polynomialsDec 22 2013This paper contains a re-evaluation of the spectral approach and factorizability for regular matrix polynomials. In addition, solvent theory is extended from the monic and comonic cases to the regular case. The classification of extended solvents (bisolvents) ... More
Solving the TTC 2011 Compiler Optimization Case with GrGen.NETNov 21 2011The challenge of the Compiler Optimization Case is to perform local optimizations and instruction selection on the graph-based intermediate representation of a compiler. The case is designed to compare participating tools regarding their performance. ... More
Rectangular Polyomino Set Weak (1,2)-achievement GamesOct 03 2010In a polyomino set (1,2)-achievement game the maker and the breaker alternately mark one and two previously unmarked cells respectively. The maker's goal is to mark a set of cells congruent to one of a given set of polyominoes. The breaker tries to prevent ... More
Generation and Transfer of Polarized Radiation in Hydrodynamical Models of the Solar ChromosphereFeb 07 2014The main goal of this thesis has been to investigate the effects that the macroscopic vertical velocity fields have on the scattering polarization signals formed in the solar chromosphere. Until now, the impact of macroscopic motions had never been considered ... More
Properties of Commutative Association Schemes derived by FGLM TechniquesJan 10 2001Association schemes are combinatorial objects that allow us solve problems in several branches of mathematics. They have been used in the study of permutation groups and graphs and also in the design of experiments, coding theory, partition designs etc. ... More
Geburtstage, Wuerfel, Produkte und KartenNov 16 2017This article, based on a talk, treats some elementary, but not completely simple examples from probability. They concern multiple birthday coincidences, throwing dice, the combinatorics of the German card game "Doppelkopf", and the properties of products ... More
A Review of Bondi--Hoyle--Lyttleton AccretionJun 07 2004Jun 21 2004If a point mass moves through a uniform gas cloud, at what rate does it accrete material? This is the question studied by Bondi, Hoyle and Lyttleton. This paper draws together the work performed in this area since the problem was first studied. Time has ... More
On the structure of the new electromagnetic conservation lawsNov 11 2003New electromagnetic conservation laws have recently been proposed: in the absence of electromagnetic currents, the trace of the Chevreton superenergy tensor, $H_{ab}$ is divergence-free in four-dimensional (a) Einstein spacetimes for test fields, (b) ... More
Induced inflation from a 5D purely kinetic scalar field formalism on warped product spacesApr 18 2007Oct 01 2007Considering a separable and purely kinetic 5D scalar field on a warped product metric background we propose a new and more general approach for inducing 4D scalar potentials on a 4D constant foliation of the 5D space-time. We obtain an induced potential ... More
Gravitational Waves generated during inflation from a 5D vacuum theory of gravity in a de Sitter expansionNov 06 2006Jan 31 2007In this letter we study the generation of gravitational waves during inflation from a 5D vacuum theory of gravity. Within this formalism, on an effective 4D de Sitter background, we recover the typical results obtained with 4D inflationary theory in general ... More
New effective coupled $F(^{(4)}\!R,\varphi)$ modified gravity from $f(^{(5)}\!R)$ gravity in five dimensionsFeb 07 2015Apr 23 2015We obtain a new kind of $F(^{(4)}\!R,\varphi)$ modified gravity theory as an effective four-dimensional (4D) theory derived from $f(^{(5)}\!R)$ gravity in five dimensions (5D). This new theory exhibits a different matter coupling than the one in BBHL ... More
Effects of Beamforming and Antenna Configurations on Mobility in 5G NRNov 15 2018The future 5G systems are getting closer to be a reality. It is envisioned, indeed, that the roll-out of first 5G network will happen around end of 2018 and beginning of 2019. However, there are still a number of issues and problems that have to be faces ... More
A New Theory for Sketching in Linear RegressionOct 14 2018Large datasets create opportunities as well as analytic challenges. A recent development is to use random projection or sketching methods for dimension reduction in statistics and machine learning. In this work, we study the statistical performance of ... More
Identifying emergency stages in Facebook posts of police departments with convolutional and recurrent neural networks and support vector machinesJan 02 2018Jan 24 2018Classification of social media posts in emergency response is an important practical problem: accurate classification can help automate processing of such messages and help other responders and the public react to emergencies in a timely fashion. This ... More
Solving the TTC 2011 Reengineering Case with GrGen.NETNov 21 2011The challenge of the Reengineering Case is to extract a state machine model out of the abstract syntax graph of a Java program. The extracted state machine offers a reduced view on the full program graph and thus helps to understand the program regarding ... More
Saying Hello World with GrGen.NET - A Solution to the TTC 2011 Instructive CaseNov 21 2011We introduce the graph transformation tool GrGen.NET (www.grgen.net) by solving the Hello World Case of the Transformation Tool Contest 2011 which consists of a collection of small transformation tasks; for each task a section is given explaining our ... More
Uniform independence for Dehn twist automorphisms of a free groupSep 21 2017Sep 19 2018McCarthy's Theorem for the mapping class group of a closed hyperbolic surface states that for any two mapping classes $\sigma,\tau \in \mathrm{Mod}(S)$ there is some power $N$ such that the group $\langle \sigma^N,\tau^N\rangle$ is either free of rank ... More
The Weak Null Condition in Free-evolution Schemes for Numerical Relativity: Dual Foliation GHG with Constraint DampingDec 16 2018All strategies for the treatment of future null-infinity in numerical relativity involve some form of regularization of the field equations. In a recent proposal that relies on the dual foliation formalism this is achieved by the use of an asymptotically ... More
On Net Maps: Examples and Nonexistence ResultsJul 04 2015A Thurston map is called nearly Euclidean if its local degree at each critical point is 2 and it has exactly four postcritical points. Nearly Euclidean Thurston (NET) maps are simple generalizations of rational Lattes maps. We investigate when such a ... More
Length Function Compatibility for Group Actions on Real TreesAug 23 2017Aug 29 2017Let $G$ be a finitely generated group. Given two length functions $\ell$ and $m$ of irreducible $G$ actions on real trees $A$ and $B$, when is the point-wise sum $\ell + m$ again the length function of an irreducible $G$ action on a real tree? In this ... More
Type II Migration: Varying Planet Mass and Disc ViscosityJul 03 2008This paper continues an earlier study of giant planet migration, examining the effect of planet mass and disc viscosity on the migration rate. We find that the migration rate of a gap-opening planet varies systematically with the planet's mass, as predicted ... More
Giant Planet Migration in Viscous Power-Law DiscsApr 03 2007Many extra-solar planets discovered over the past decade are gas giants in tight orbits around their host stars. Due to the difficulties of forming these `hot Jupiters' in situ, they are generally assumed to have migrated to their present orbits through ... More
Drops on an inclined heterogeneous substrate: onset of sliding motionMar 08 2006Pinning and depinning of drops on an inclined heterogeneous substrate is studied as a function of the inclination and heterogeneity amplitude. Two types of heterogeneity are considered: a hydrophobic defect that blocks the droplet in front, and a hydrophilic ... More
Transseries: Composition, Recursion, and ConvergenceSep 07 2009Additional remarks and questions for transseries. In particular: properties of composition for transseries; the recursive nature of the construction of R[[[ x ]]]; modes of convergence for transseries. There are, at this stage, questions and missing proofs ... More
Transseries: Ratios, Grids, and WitnessesSep 13 2009More remarks and questions on transseries. In particular we deal with the system of ratio sets and grids used in the grid-based formulation of transseries. This involves a "witness" concept that keeps track of the ratios required for each computation. ... More
An algebraic and graph theoretical framework to study monomial dynamical systems over a finite fieldNov 08 2007Jul 30 2008An n dimensional monomial dynamical system over a finite field K is a nonlinear deterministic time discrete dynamical system with the property that each of the n component functions is a monic nonzero monomial function in n variables. In this paper we ... More
Marginally stable circular orbits in stationary axisymmetric spacetimesDec 29 2015Aug 04 2016We derive a necessary condition for the existence of marginally stable circular orbits of test particles in stationary axisymmetric spacetimes which possess a refection symmetry with respect to the equatorial plane; photon orbits are also addressed. Energy ... More
Faster deterministic integer factorizationJan 10 2012The best known unconditional deterministic complexity bound for computing the prime factorization of an integer N is O(M_int(N^(1/4) log N)), where M_int(k) denotes the cost of multiplying k-bit integers. This result is due to Bostan--Gaudry--Schost, ... More
Proofs of existence of local potentials for trace-free symmetric 2-forms using dimensionally dependent identitiesJul 01 2004We exploit four-dimensional tensor identities to give a very simple proof of the existence of a Lanczos potential for a Weyl tensor in four dimensions with any signature, and to show that the potential satisfies a simple linear second order differential ... More
On Effective Constraints for the Riemann-Lanczos System of EquationsFeb 05 2003There have been conflicting points of view concerning the Riemann--Lanczos problem in 3 and 4 dimensions. Using direct differentiation on the defining partial differential equations, Massa and Pagani (in 4 dimensions) and Edgar (in dimensions n > 2) have ... More
One-shot distributed ridge regression in high dimensionsMar 22 2019In many areas, practitioners need to analyze large datasets that challenge conventional single-machine computing. To scale up data analysis, distributed and parallel computing approaches are increasingly needed. Datasets are spread out over several computing ... More
Transseries for beginnersJan 31 2008Jul 15 2009From the simplest point of view, transseries are a new kind of expansion for real-valued functions. But transseries constitute much more than that--they have a very rich (algebraic, combinatorial, analytic) structure. The set of transseries is a large ... More
Torus Curves With Vanishing CurvatureMar 06 1998Let T be the standard torus of revolution in R^3 with radii b and 1, 0<b<1. Let \alpha be a (p,q) torus curve on T. We show that there are points of zero curvature on \alpha for only one value of the variable radius of T, b=p^2/(p^2+q^2). The curve \alpha ... More
Regularity Properties for Sparse RegressionMay 22 2013Dec 05 2015Statistical and machine learning theory has developed several conditions ensuring that popular estimators such as the Lasso or the Dantzig selector perform well in high-dimensional sparse regression, including the restricted eigenvalue, compatibility, ... More
Polyakov-Nambu-Jona-Lasinio phase diagrams and quarkyonic phase from order parametersDec 04 2013We show that the magnitude of the order parameters in Polyakov-Nambu-Jona-Lasinio (PNJL) model, given by the quark condensate and the Polyakov loop, can be used as a criterium to clearly identify, without ambiguities, phases and boundaries of the strongly ... More
New infrared star clusters in the Northern and Equatorial Milky Way with 2MASSApr 22 2003We carried out a survey of infrared star clusters and stellar groups on the 2MASS J, H and K_s all-sky release Atlas in the Northern and Equatorial Milky Way (350 < l < 360, 0 < l < 230). The search in this zone complements that in the Southern Milky ... More
Coupled scalar fields Oscillons and Breathers in some Lorentz Violating ScenariosDec 18 2012Feb 27 2015In this work we discuss the impact of the breaking of the Lorentz symmetry on the usual oscillons, the so-called flat-top oscillons, and the breathers. Our analysis is performed by using a Lorentz violation scenario rigorously derived in the literature. ... More
Correlations between critical parameters and bulk properties of nuclear matterOct 06 2016The present work starts by providing a clear identification of correlations between critical parameters ($T_c$, $P_c$, $\rho_c$) and bulk quantities at zero temperature of relativistic mean-field models (RMF) presenting third and fourth order self-interactions ... More
An alternative approach to viscosity in an accretion discSep 27 2006Oct 02 2006Purely hydrodynamic numerical experiments into the evolution of astrophysical discs typically include some sort of viscosity in order to cause accretion. In this paper, we demonstrate an alternative method of implementing viscous forces, with extremely ... More
Trapping effects in inflation: blue spectrum at small scalesNov 19 2015Jul 07 2016We consider the inflationary model in which the inflaton $\phi$ couples to another scalar field $\chi$ via the interaction $g^2(\phi-\phi_0)^2\chi^2$ with a small coupling constant $g$ ($g^2 \sim 10^{-7}$). We assume that there is a sequence of "trapping ... More
High-Dimensional Asymptotics of Prediction: Ridge Regression and ClassificationJul 10 2015Nov 04 2015We provide a unified analysis of the predictive risk of ridge regression and regularized discriminant analysis in a dense random effects model. We work in a high-dimensional asymptotic regime where $p, n \to \infty$ and $p/n \to \gamma \in (0, \, \infty)$, ... More
Triezenberg-Zwanzig expression for the surface tension of a liquid dropMay 01 2013Formulas, analogous to the Triezenberg-Zwanzig expression for the surface tension of a planar interface, are presented for the Tolman length, the bending rigidity, and the rigidity constant associated with Gaussian curvature. These expressions feature ... More