Results for "Oscar Peitl"

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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
Stabilization of 2D Quantum Gravity by branching interactionsOct 04 1995In this paper the stabilization of 2D quantum Gravity by branching interactions is considered. The perturbative expansion and the first nonperturbative term of the stabilized model are the same than the unbounded matrix model which define pure Gravity, ... More
A family of Solutions of the N-Body ProblemOct 07 2014In this paper we characterize all the solutions of the three body problem on which one body with mass $m_1$ remains in a fixed line and the other two bodies have the same mass $m_2$. We show that all the solutions with negative total energy (potential ... More
A Nearly Quaternionic Structure on SU(3)Aug 28 2009It is shown that the compact Lie group SU(3) admits an Sp(2)Sp(1)-structure whose distinguished 2-forms $\omega_1,\omega_2,\omega_3$ span a differential ideal. This is achieved by first reducing the structure further to a subgroup isomorphic to SO(3). ... More
Complexity of a Tetris variantJun 23 2015In this paper we are going to solve an open problem about the game tetris. We are going to give the first results in the complexity of a variant of offline tetris introduced by Erik Demaine, Susan Hohenberger and David Liben Nowell in their paper "Tetris ... More
Prospects for Higgs boson scenarios beyond the Standard ModelFeb 26 2014The new particle recently discovered at the Large Hadron Collider has properties compatible with those expected for the Standard Model (SM) Higgs boson. However, this does not exclude the possibility that the discovered state is of non-standard origin, ... More
Searches for strong dynamics signals in gauge boson pair productionMay 13 2013I briefly review the construction of the effective field theory of a nonlinearly realized electroweak symmetry breaking and apply it to the study of gauge boson pair production. I will consider WW, ZZ and \gamma Z production at linear colliders as reference ... More
Genome and transcriptome studies of the protozoan parasites Trypanosoma cruzi and Giardia intestinalisNov 18 2012Trypanosoma cruzi and Giardia intestinalis are two human pathogens and protozoan parasites responsible for the diseases Chagas disease and giardiasis, respectively. Both diseases cause suffering and illness in several million individuals. The former disease ... More
Domain Adaptations for Computer Vision ApplicationsNov 20 2012A basic assumption of statistical learning theory is that train and test data are drawn from the same underlying distribution. Unfortunately, this assumption doesn't hold in many applications. Instead, ample labeled data might exist in a particular `source' ... More
CMC hypersurfaces on riemannian and semi-riemannian manifoldsApr 13 2009In this paper we show explicit examples of several families of immersions with constant mean curvature and non constant principal curvatures, in semi-riemannian manifolds with constant sectional curvature. In particular, we prove that every h in [-1,-2 ... More
New angles on top quark decay to a charged Higgs BosonSep 05 2008Top quarks produced in pairs are predicted to experience spin correlations. Due to the large ttbar statistics expected for the LHC, it should be possible to search for new physics effects in angular variables sensitive to these correlations. We investigate, ... More
Application of the Large-N_c limit to a Chiral Lagrangian with ResonancesDec 02 2002It is shown that the implementation of the Large--$N_c$ approximation helps to get insight into the structure of, in principle, any QCD-like theory. As an example, we will compute the NLO corrections to $L_{10}$ in the chiral limit with a Lagrangian with ... More
Cohort aggregation modelling for complex forest stands: Spruce-aspen mixtures in British ColumbiaOct 24 2016Oct 25 2016Mixed-species growth models are needed as a synthesis of ecological knowledge and for guiding forest management. Individual-tree models have been commonly used, but the difficulties of reliably scaling from the individual to the stand level are often ... More
F-flatness and universality in broken SupergravityNov 27 2002We show that in a broken supergravity theory any field that acquires a vacuum expectation value obtains at the same time a non vanishing F-term whose natural size is given by $<\theta> m_{3/2}$. These F-terms contribute unsuppressed to the trilinear couplings ... More
Sums and differences of four k-th powersDec 08 2009Dec 22 2010We prove an upper bound for the number of representations of a positive integer $N$ as the sum of four $k$-th powers of integers of size at most $B$, using a new version of the Determinant method developed by Heath-Brown, along with recent results by ... More
Fracture driven by a Thermal GradientMay 12 1995Motivated by recent experiments by Yuse and Sano (Nature, 362, 329 (1993)), we propose a discrete model of linear springs for studying fracture in thin and elastically isotropic brittle films. The method enables us to draw a map of the stresses in the ... More
On the Universality of Nonperturbative effects in Stabilized 2D Quantum GravityOct 26 1994Nov 08 1994In this letter I study the universality of the nonperturbative effects and the vacua structure of the stochastic stabilization of the matrix models which defines Pure 2D Quantum Gravity. I show also that there is not tunneling, in the continuum limit, ... More
Flavour symmetries and SUSY soft breaking in the LHC eraOct 19 2007The so-called supersymmetric flavour problem does not exist in isolation to the Standard Model flavour problem. We show that a realistic flavour symmetry can simultaneously solve both problems without ad hoc modifications of the SUSY model. Furthermore, ... More
The Least Wrong Model Is Not in the DataApr 03 2014Apr 17 2014The true process that generated data cannot be determined when multiple explanations are possible. Prediction requires a model of the probability that a process, chosen randomly from the set of candidate explanations, generates some future observation. ... More
Constraints on the two-Higgs-doublet modelSep 28 2009The two-Higgs-doublet model provides a simple, yet interesting, generalization of the SM Higgs sector. We study the CP-conserving version of this model with general, flavor-diagonal, Yukawa couplings. Indirect constraints are obtained from flavor physics ... More
Revisiting ZZ and γZ production with effective field theoriesApr 03 2013A complete and systematic effective field theory analysis of new physics effects in \bar{f}f -> ZZ and \bar{f}f -> \gamma Z is performed. Results are presented for the different initial and final-state polarized differential cross sections in terms of ... More
Textos de Fisica para professores e estudantes--IIJul 28 2005Aug 24 2005This paper has been withdrawn by the author.
An Efficient Algorithm to Calculate the Center of the Biggest Inscribed Circle in an Irregular PolygonDec 13 2012In this paper, an efficient algorithm to find the center of the biggest circle inscribed in a given polygon is described. This work was inspired by the publication of Daniel Garcia-Castellanos & Umberto Lombardo and their algorithm used to find a landmass' ... More
A generalization of the Bombieri-Pila determinant methodMay 27 2009Dec 22 2010The so-called determinant method was developed by Bombieri and Pila in 1989 for counting integral points of bounded height on affine plane curves. In this paper we give a generalization of that method to varieties of higher dimension, yielding a proof ... More
Quotient normed conesJul 25 2006Given a normed cone $(X,p)$ and a subcone $Y,$ we construct and study the quotient normed cone $(X/Y,\tilde{p})$ generated by $Y$. In particular we characterize the bicompleteness of $(X/Y,\tilde{p})$ in terms of the bicompleteness of $(X,p),$ and prove ... More
Diophantine equations in moderately many variablesJul 06 2016We give upper bounds for the number of integral solutions of bounded height to a system of equations $f_i(x_1,\ldots,x_n) = 0$, $1 \leq i \leq r$, where the $f_i$ are polynomials with integer coefficients. The estimates are obtained by generalising an ... More
Short CalculusOct 24 2001Sep 27 2004This paper has been withdrawn by the author.
Kinematics on oblique axesNov 27 2001We solve a difficult problem involving velocity and acceleration components along oblique axes, and propose two problems of central force motion to be solved using oblique axes.
Tools for charged Higgs bosonsDec 13 2010We review the status of publicly available software tools applicable to charged Higgs physics. A selection of codes are highlighted in more detail, focusing on new developments that have taken place since the previous charged Higgs workshop in 2008. We ... More
Embedded constant mean curvature hypersurfaces on spheresMar 07 2009Let m>1 and n>1 be any pair of integers. In this paper we prove that if H is between the numbers \cot(\frac{\pi}{m}) and b_{m,n}=\frac{(m^2-2)\sqrt{n-1}}{n\sqrt{m^2-1}}, then, there exists a non isoparametric, compact embedded hypersurface in S^{n+1} ... More
Towards understanding Regge trajectories in holographic QCDMay 23 2006Jul 12 2007We reassess a work done by Migdal on the spectrum of low-energy vector mesons in QCD in the light of the AdS-QCD correspondence. Recently, a tantalizing parallelism was suggested between Migdal's work and a family of holographic duals of QCD. Despite ... More
Integral representation of the Ising modelOct 17 2005The partition function of the 2D Ising model coupled to an external magnetic field is studied. We show that the sum over the spin variables can be reduced to an integration over a finite number of variables. This integration must be performed numerically. ... More
Rotational Surfaces in S^3 with constant mean curvatureSep 17 2012Very recently Ben Andrews and Haizhong Li showed that every embedded cmc torus in the three dimensional sphere is axially symmetric. There is a two-parametric family of axially symmetric cmc surfaces; more precisely, for every real number H and every ... More
A family of periodic solutions of the three body problem. Light versionSep 16 2015In this paper we describe a 1-dimensional family of initial conditions \Sigma that provides reduced periodic solution of the three body problem. This family \Sigma contains a bifurcation point and extend the periodic solution described in (Perdomo, http://arxiv.org/pdf/1507.01100.pdf). ... More
Notes on the spaces of bilinear multipliersMay 26 2009A locally integrable function $m(\xi,\eta)$ defined on $\mathbb R^n\times \mathbb R^n$ is said to be a bilinear multiplier on $\mathbb R^n$ of type $(p_1,p_2, p_3)$ if $$ B_m(f,g)(x)=\int_{\mathbb R^n} \int_{\mathbb R^n}\hat f(\xi)\hat g(\eta)m(\xi,\eta)e^{2\pi ... More
A handle is enough for a hard game of PullMay 29 2016We are going to show that some variants of a puzzle called Pull in which the boxes have handles (i.e. we can only pull the boxes in certain directions) are NP-hard
EWSB from strongly-coupled dynamics: an EFT approach and implications for WW productionMay 23 2013If the dynamics behind EWSB are of strongly-coupled nature, the Standard Model ceases to be renormalizable and should be instead understood as an effective field theory (EFT). Here I will discuss the systematics behind this effective field theory description. ... More
Understanding the differences in neutrino and charged-fermion flavour structuresApr 11 2005May 20 2005We present a new mechanism to explain naturally and through a common flavour symmetry the mildly hierarchical neutrino masses with large mixings and the hierarchical Yukawa matrices with small mixing angles. Although this mechanism is not linked to a ... More
Algebraic zero mean curvature varieties in semi-riemannian manifoldsMar 13 2009In this paper we provide a family of algebraic space-like surfaces in the three dimensional anti de Sitter space that shows that this Lorentzian manifold admits algebraic maximal examples of any order. Then, we classify all the space-like order two algebraic ... More
Recent developments in nonleptonic kaon decaysAug 01 2013I review the current status of nonleptonic kaon decays, placing special emphasis on the recent theoretical progress. In particular, I concentrate on 3 points: (i) the improved determination of \epsilon_K, including both perturbative and nonperturbative ... More
Chiral methods at the electroweak scaleDec 22 2015I review the main features of the effective field theory (EFT) behind scenarios of dynamical electroweak symmetry breaking, placing particular emphasis on the systematics and the parallels that can be drawn with Chiral Perturbation Theory. The notion ... More
Random Sampling in an Age of Automation: Minimizing Expenditures through Balanced Collection and AnnotationOct 26 2014Aug 21 2015Methods for automated collection and annotation are changing the cost-structures of sampling surveys for a wide range of applications. Digital samples in the form of images or audio recordings can be collected rapidly, and annotated by computer programs ... More
Lurking pseudovectors below the TeV scaleFeb 20 2014If electroweak symmetry breaking is driven by a new strongly-coupled dynamical sector, one expects their bound states to appear at the TeV scale or slightly below. However, electroweak precision data imposes severe constraints on most of the existing ... More
AdS$_4$ solutions of massive IIA from dyonic ISO(7) supergravitySep 23 2015Jul 18 2016Explicit formulae are given for the consistent truncation of massive type IIA supergravity on the six-sphere to the SU(3)--invariant sector of $D=4$ ${\cal N}=8$ supergravity with dyonic ISO(7) gauging. These formulae are then used to construct AdS$_4$ ... More
Strongly hyperbolic systems in General RelativityMar 01 2004We discuss several topics related to the notion of strong hyperbolicity which are of interest in general relativity. After introducing the concept and showing its relevance we provide some covariant definitions of strong hyperbolicity. We then prove that ... More
Hexagonal Lattice Points on CirclesAug 11 2005We study the hexagonal lattice $\mathbb{Z}[\omega]$, where $\omega^6=1$. More specifically, we study the angular distribution of hexagonal lattice points on circles with a fixed radius. We prove that the angles are equidistributed on average, and suggest ... More
The density of integral points on hypersurfaces of degree at least fourAug 21 2008Jul 07 2009Let $f$ be a polynomial of degree at least four with integer-valued coefficients. We establish new bounds for the density of integer solutions to the equation $f=0$, using an iterated version of Heath-Browns $q$-analogue of van der Corput's method of ... More
Spectrum of the Laplacian and the Jacobi operator on rotational cmc hypersurfaces of spheresFeb 19 2019Let $M\subset \mathbb{S}^{n+1}\subset\mathbb{R}^{n+2}$ be a compact cmc rotational hypersurface of the $(n+1)$-dimensional Euclidean unit sphere. Denote by $|A|^2$ the square of the norm of the second fundamental form and $J(f)=-\Delta f-nf-|A|^2f$ the ... More
Notes on Linear AlgebraOct 29 2001Sep 27 2004This paper has been withdrawn by the author.
Nonperturbative Ground State of the Stochastic Stabilization of 2D Quantum GravityOct 14 1993May 23 1994I construct the ground state, up to first nonperturbative order, of the stochastic stabilization of the zero dimensional matrix model which defines 2D Quantum Gravity. It is given by the linear combination of a perturbative wave function and a nonperturbative ... More
Reduction of internal degrees of freedom in the large N limit in matrix modelsJun 02 1997Nov 05 1998In this paper the large $N$ limit of one hermitian matrix models coupled to an external matrix is considered. It is shown that in the large N limit the number of degrees of freedom are reduced to be order N even though it is order $N^{2}$ for finite N. ... More
Trotter formula and thermodynamic limitsFeb 03 2002We discuss the interchangeability of the thermodynamic limit \beta \to \infty and the infinite limit of the Trotter number n \to \infty when Trotter formula e^{H_{0}+V} =\lim_{n \to \infty} (e^{H_{0}/n} e^{V/n}) is used to calculate partition functions ... More
Some Computations for Binomial Edge Ideals and Koszul DualityDec 11 2014We make some observations on binomial edge ideals, with the characterization of their Koszulness as motivation. Inspired by results of Ene, Herzog and Hibi, we discuss building Koszul graphs from smaller pieces in a controlled manner. We characterize ... More
A small variation of the Taylor Method and periodic solutions of the 3-body problemJul 04 2015In this paper we define a small variation of the Taylor method and a formula for the global error of this new numerical method that allows us to keep track of the round-off error and does not require previous knowledge of the exact solution. As an application ... More
Textos de física para professores e estudantesJul 04 2003This is a series of short teaching papers dealing with specific topics in a standard first-year undergraduate Physics course. ----- Este texto comp\~oe-se de quatro pequenas notas -- independentes entre si -- em que se discutem alguns t\'opicos espec\'{\i}ficos ... More
The complete $D=11$ embedding of SO(8) supergravityDec 15 2015The truncation formulae of $D=11$ supergravity on $S^7$ to $D=4$ ${\cal N} =8$ SO(8)-gauged supergravity are completed to include the full non-linear dependence of the $D=11$ three-form potential $\hat A_{(3)}$ on the $D=4$ fields, and their consistency ... More
The density of integral points on complete intersectionsJan 03 2007Jan 05 2007In this paper, an upper bound for the number of integral points of bounded height on an affine complete intersection defined over $\mathbb{Z}$ is proven. The proof uses an extension to complete intersections of the method used for hypersurfaces by Heath-Brown, ... More
The gambler's ruin problem in path representation formNov 22 2001We consider the classical one-dimensional random walk of a particle on the right-half real line. We assume that the particle is initially at position x=k, k > 0, and moves to the right with probability p or to the left with probability 1-p. We consider ... More
Padé approximants and the prediction of non-perturbative parameters in particle physicsSep 16 2010Commonly used techniques to study non-perturbative aspects of the strong interactions have a deep connection with rational approximants, and in particular with Pad\'e approximants to meromorphic functions. However, only recently this connection has been ... More
PivotCompress: Compression by SortingNov 19 2014Nov 21 2014Sorted data is usually easier to compress than unsorted permutations of the same data. This motivates a simple compression scheme: specify the sorted permutation of the data along with a representation of the sorted data compressed recursively. The sorted ... More
Symmetry and holonomy in M TheoryJul 13 2006In this PhD Thesis, supersymmetry and its formulation in the context of D=11 supergravity is discussed from several perspectives. The role of generalized holonomy as a classification tool of supersymmetric supergravity solutions is reviewed, with particular ... More
Meson Electroweak Interactions in Multicolor Quantum ChromodynamicsOct 11 2005This PhD Thesis is mainly devoted to the study of hadronic matrix elements of kaons. Its inner structure can be divided in three parts. In Chapter 3 we address the issue of quantum corrections in Resonance Chiral Lagrangians with the aid of the 1/N_c ... More
Impact of Duality Violations on Spectral Sum Rule AnalysesOct 10 2005Recent sum rule analyses on the <VV-AA> two-point correlator have led to significant discrepancies in the values found for the OPE condensates, most dramatically in the dimension eight condensate and to a lesser extent in the dimension six one. Precise ... More
Pair creation of particles and black holes in external fieldsJun 26 2001It is well known that massive black holes may form through the gravitational collapse of a massive astrophysical body. Less known is the fact that a black hole can be produced by the quantum process of pair creation in external fields. These black holes ... More
On the Nature of Nonperturbative Effects in Stabilized 2D Quantum GravitySep 27 1993We remark that the weak coupling regime of the stochastic stabilization of 2D quantum gravity has a unique perturbative vacuum, which does not support instanton configurations. By means of Monte Carlo simulations we show that the nonperturbative vacuum ... More
Exponential Decay for Small Non-Linear Perturbations of Expanding Flat Homogeneous CosmologiesFeb 01 1999It is shown that during expanding phases of flat homogeneous cosmologies all small enough non-linear perturbations decay exponentially. This result holds for a large class of perfect fluid equations of state, but notably not for very ``stiff'' fluids ... More
On the Newtonian Limit of General RelativityJun 29 1995We find a choice of variables for the 3+1 formulation of general relativity which casts the evolution equations into (flux-conservative) symmetric-hyperbolic first order form for arbitrary lapse and shift, for the first time. We redefine the lapse function ... More
Embeddings between operator-valued dyadic BMO spacesMay 06 2008We investigate a scale of dyadic operator-valued BMO spaces, corresponding to the different yet equivalent characterizations of dyadic BMO in the scalar case. In the language of operator spaces, we investigate different operator space structures on the ... More
Operator-valued dyadic BMO spacesMay 01 2008We consider BMO spaces of operator-valued functions, among them the space of operator-valued functions $B$ which define a bounded paraproduct on $L^2(H)$. We obtain several equivalent formulations of $\|\pi_B\|$ in terms of the norm of the "sweep" function ... More
Human Pose Estimation from RGB Input Using Synthetic Training DataMay 06 2014May 27 2014We address the problem of estimating the pose of humans using RGB image input. More specifically, we are using a random forest classifier to classify pixels into joint-based body part categories, much similar to the famous Kinect pose estimator [11], ... More
Elementary deformations and the hyperKähler-quaternionic Kähler correspondenceApr 04 2014Apr 12 2014The hyperK\"ahler-quaternionic K\"ahler correspondence constructs quaternionic K\"ahler metrics from hyperK\"ahler metrics with a rotating circle symmetry. We discuss how this may be interpreted as a combination of the twist construction with the concept ... More
Extended Security Risks in IP NetworksSep 23 2013Exploitation techniques targeting intermediate (transit) network nodes in public and private networks have been theoretically known and empirically proven to work for quite some time. However, very little effort has been made to look into the network-specific ... More
Transference of bilinear multiplier operators on Lorentz spacesSep 27 2007Sep 30 2007We prove a DeLeeuw type theorem of transference of boundedness for modulation invariant multiplier operators between the groups defined by the real line and the torus.
Chiral Perturbation Theory with tensor sourcesMay 21 2007Sep 21 2007We construct the most general chirally-invariant Lagrangian for mesons in the presence of external sources coupled to the tensor current \bar{\psi}\sigma_{\mu\nu}\psi. In order to have only even terms in the chiral expansion, we consider the new source ... More
Observations on the Darboux coordinates for rigid special geometryFeb 24 2006Apr 21 2006We exploit some relations which exist when (rigid) special geometry is formulated in real symplectic special coordinates $P^I=(p^\Lambda,q_\Lambda), I=1,...,2n$. The central role of the real $2n\times 2n$ matrix $M(\Re \mathcal{F},\Im \mathcal{F})$, where ... More
Compton effect: interacting particles or interacting wavesAug 16 2005Traditional textbook explanations of the Compton effect treat the photon electron interaction as a particle collision. This explanation is a pedagogical disaster, implying that sometimes interactions are particle-like whereas quantum mechanics always ... More
Can Cosmic Rays Interacting With Molecular Clouds Explain The Galactic Center Gamma-Ray Excess?Oct 29 2014The Fermi Large Area Telescope data appear to have an excess of gamma rays from the inner 150 pc of the Galactic Center (GC). The main explanations proposed for this are: an unresolved population of millisecond pulsars (MSPs), dark matter (DM) annihilation, ... More
Equilibrium Shapes of Cylindrical Rotating Liquid DropsApr 11 2014See http://www.youtube.com/watch?v=izbGXdjvK_I for a YouTube video showing part of the results in this paper.We will consider surfaces whose mean curvature at a point is a linear function of the square of the distance from that point to the vertical axis. ... More
Constant Speed RampsMay 02 2013In this paper we show all possible ramps where an object can move with constant speed under the effect of gravity and friction. The planar ramp are very easy to describe, just rotate a curve with velocity vector (tanh(as),sech(as)). Recall that tanh(as)^2+sech^2(as) ... More
Energy in computing systems with speed scaling: optimization and mechanisms designDec 27 2012We study a simple scheduling game for the speed scaling model. Players want their job to complete early, which however generates a big energy consumption. We address the game from the mechanism design side, and by charging the energy usage to the players ... More
Pair creation of anti-de Sitter black holes on a cosmic string backgroundJan 12 2004We analyze the quantum process in which a cosmic string breaks in an anti-de Sitter (AdS) background, and a pair of charged or neutral black holes is produced at the ends of the strings. The energy to materialize and accelerate the pair comes from the ... More
Relations among tautological classes revisitedDec 07 2010We give a simple generalisation of a theorem of Morita, which leads to a great number of relations among tautological classes on moduli spaces of curves.
Embedded Cobordism Categories and Spaces of ManifoldsDec 13 2009Galatius, Madsen, Tillmann and Weiss have identified the homotopy type of the classifying space of the cobordism category with objects (d-1)-dimensional manifolds embedded in R^\infty. In this paper we apply the techniques of spaces of manifolds, as developed ... More
Chiral corrections to the f_V^T/f_V ratio for vector mesonsJul 30 2009In this letter we compute the leading chiral corrections to the ratio between the tensor and the vector decay couplings for the lowest lying vector meson multiplet (rho, K^*, phi). We show that the leading chiral logarithms arise from tadpole contributions ... More
A two end family of solutions for the Inhomogeneous Allen-Cahn equation in R^2May 23 2013In this work we construct a family of entire bounded solution for the singulary perturbed Inhomogeneous Allen-Cahn Equation $\ep^2\div\left(a(x)\nabla u\right)-a(x)F'(u)=0$ in $\R^2$, where $\ep\to 0$. The nodal set of these solutions is close to a "nondegenerate" ... More
Martingale approach to optimal portfolio-consumption problems in Markov-modulated pure-jump modelsJun 12 2014We study optimal investment strategies that maximize expected utility from consumption and terminal wealth in a pure-jump asset price model with Markov-modulated (regime switching) jump-size distributions. We give sufficient conditions for existence of ... More
Magnetic history dependence of metastable states in systems with dipolar interactionsDec 02 1999Dec 22 1999We present the results of a Monte Carlo simulation of the ground state and magnetic relaxation of a model of a thin film consisting on a two-dimensional square lattice of Heisenberg spins with perpendicular anisotropy K, exchange J and long-range dipolar ... More
Motion of a helical vortexAug 02 2015We study the motion of a single helical vortex in an unbounded, inviscid, incompressible fluid. The vortex is an infinite tube whose centerline is a helix and whose cross section is a circle of small radius (compared to the radius of curvature) where ... More
The stable cohomology of automorphisms of free groups with coefficients in the homology representationDec 07 2010We study the cohomology of Aut(F_n) and Out(F_n) with coefficients in the modules \wedge^q H, \wedge H^*, Sym^q H or Sym^q H^*, where H is the Out(F_n)-module obtained by abelianising the free group F_n. For reasons which are not conceptually clear, taking ... More
The treadmillsled of a curveMay 17 2011In a previous paper the author introduced the notion of TreadmillSled of a curve, which is an operator that takes regular curves in R^2 to curves in R^2. This operator turned out to be very useful to describe helicoidal surfaces, for example, it provides ... More
Algebraic constant mean curvature surfaces in Euclidean spaceFeb 01 2010In this paper we prove that the only algebraic constant mean curvature (cmc) surfaces in R^3 of order less than four are the planes, the spheres and the cylinders. The method used heavily depends on the efficiency of algorithms to compute Groebner Bases ... More
Notes on bilinear multipliers on Orlicz spacesFeb 04 2019Let $\Phi_1 , \Phi_2 $ and $ \Phi_3$ be Young functions and let $L^{\Phi_1}(\mathbb{R})$, $L^{\Phi_2}(\mathbb{R})$ and $L^{\Phi_3}(\mathbb{R})$ be the corresponding Orlicz spaces. We say that a function $m(\xi,\eta)$ defined on $\mathbb{R}\times \mathbb{R}$ ... More
An upper bound for the concordance stable rangeNov 27 2015We prove that the concordance stable range for manifolds of dimension $2n$ can be no better than $2n-2$. In order to do so, we define new characteristic classes for block bundles, extending earlier work with Ebert, and prove their non-triviality.
The Existence of $ω$-Chains for Transitive Mixed Linear Relations and Its ApplicationsOct 31 2001Apr 29 2005We show that it is decidable whether a transitive mixed linear relation has an $\omega$-chain. Using this result, we study a number of liveness verification problems for generalized timed automata within a unified framework. More precisely, we prove that ... More
How To Use SU(3)-Flavor Symmetry to Extract CP Violating Phases and Strong Phase Shifts at CLEOFeb 20 1995After a short introduction to the SM picture of CP violation, we discuss recent work on how to use SU(3) flavor symmetry, along with some dynamical approximations, to extract the CKM weak phases and the strong rescattering phases from experimental measurements ... More
The Contribution of Cosmic Rays Interacting With Molecular Clouds to the Galactic Center Gamma-Ray ExcessDec 23 2013Mar 12 2014The Fermi-LAT data appear to have an excess of gamma rays from the inner 150 pc of the Galactic Center. The main explanations proposed for this are: an unresolved population of millisecond pulsars (MSPs), dark matter (DM) annihilation, and nonthermal ... More
Role of Van der Waals forces in graphene adsorption over Pd, Pt and NiFeb 28 2013We report ab initiocomputations with the Vienna ab Initio Simulation Package (VASP) aimed at elucidating the adsorption mechanism of graphene-like structures on (111) Pd, Pt, and Ni surfaces. To study the adsorption properties, we simulate an already-formed ... More
A New Construction for LDPC Codes using Permutation Polynomials over Integer RingsJun 24 2005A new construction is proposed for low density parity check (LDPC) codes using quadratic permutation polynomials over finite integer rings. The associated graphs for the new codes have both algebraic and pseudo-random nature, and the new codes are quasi-cyclic. ... More
Effective Theory of a Dynamically Broken Electroweak Standard Model at NLOMar 29 2012Aug 23 2012We consider the Standard Model as an effective theory at the weak scale $v$ of a generic new strong interaction that dynamically breaks electroweak symmetry at the energy scale $\Lambda\sim $ (few) TeV. Assuming only the minimal field content with the ... More
The Exchange of Orientifold Two-Planes in M-theoryMar 31 2003Nov 04 2003We propose an M-theory lift picture of the exchange among type IIA orientifold two-planes. This consists in wrapping a M5-brane on a three-cycle in the transverse space of the M-theory orientifold plane OM2. A flux quantization condition for the three-form ... More