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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

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

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

Textos de Fisica para professores e estudantes--IIJul 28 2005Aug 24 2005This paper has been withdrawn by the author.

Spectrum of the Laplacian and the Jacobi operator on rotational cmc hypersurfaces of spheresFeb 19 2019Mar 06 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

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

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

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

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

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

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

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

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.

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

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

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

Theory of Probability. A Historical EssayFeb 27 2018This book covers the history of probability up to Kolmogorov with essential additional coverage of statistics up to Fisher. Based on my work of ca. 50 years, it is the only suchlike book. Gorrochurn (2016) is similar but his study of events preceding ... More

Estimating reducible stochastic differential equations by conversion to a least-squares problemOct 16 2017Jun 23 2018Stochastic differential equations (SDEs) are increasingly used in longitudinal data analysis, compartmental models, growth modelling, and other applications in a number of disciplines. Parameter estimation, however, currently requires specialized software ... More

Flexible In-The-Field MonitoringMay 20 2017Fully assessing the robustness of a software application in-house is infeasible, especially considering the huge variety of hardly predictable stimuli, environments, and configurations that applications must handle in the field. For this reason, modern ... 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

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

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

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

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 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

A handle is enough for a hard game of PullMay 29 2016Dec 29 2017We 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

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

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

A new metric of consensus for Likert scalesSep 27 2018Oct 25 2018In this study we present a metric of consensus for Likert scales. The measure gives the level of agreement as the percentage of consensus among respondents. The proposed framework allows to design a positional indicator that gives the degree of agreement ... More

Unramified affine Springer fibers and isospectral Hilbert schemesAug 07 2018For any connected reductive group $G$ over $\mathbb{C}$, we revisit Goresky-Kottwitz-MacPherson's description of the torus equivariant (co)homology of affine Springer fibers $\mathrm{Sp}_\gamma\subset \mathrm{Gr}_G$, where $\gamma=at^d$, and $a$ is a ... More

An Abstract Method Linearization for Detecting Source Code Plagiarism in Object-Oriented EnvironmentNov 29 2017Despite the fact that plagiarizing source code is a trivial task for most CS students, detecting such unethical behavior requires a considerable amount of effort. Thus, several plagiarism detection systems were developed to handle such issue. This paper ... 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

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

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

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

A remark on the Liouville problem for stationary Navier-Stokes equations in Lorentz and Morrey spacesMar 02 2019The Liouville problem for the stationary Navier-Stokes equations on the whole space is a challenging open problem who has know several recent contributions. We prove here some Liouville type theorems for these equations provided the velocity field belongs ... 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

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

Homology of Hilbert schemes of reducible locally planar curvesNov 17 2017Let $C$ be a complex, reduced, locally planar curve. We extend the results of Rennemo arXiv:1308.4104 to reducible curves by constructing an algebra $A$ acting on $V=\bigoplus_{n\geq 0} H_*(C^{[n]}, \mathbb{Q})$, where $C^{[n]}$ is the Hilbert scheme ... More

Computing the $A_α-$ eigenvalues of a bugOct 08 2017Let $G$ be a simple undirected graph. For $\alpha \in [0,1]$, let \begin{equation*} A_{\alpha}\left( G\right) =\alpha D\left( G\right) +(1-\alpha)A\left( G\right) , \end{equation*} where $A(G)$ is the adjacency matrix of $G$ and $D(G)$ is the diagonal ... 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

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

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

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

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

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

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

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

A remark on the Liouville problem for stationary Navier-Stokes equations in Lorentz and Morrey spacesMar 02 2019Mar 08 2019The Liouville problem for the stationary Navier-Stokes equations on the whole space is a challenging open problem who has know several recent contributions. We prove here some Liouville type theorems for these equations provided the velocity field belongs ... 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

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

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

$A_α$-spectrum of a graph obtained by copies of a rooted graph and applicationsApr 22 2017Given a connected graph $R$ on $r$ vertices and a rooted graph $H,$ let $R\{H\}$ be the graph obtained from $r$ copies of $H$ and the graph $R$ by identifying the root of the $i-th$ copy of $H$ with the $i-th$ vertex of $R$. Let $0\leq\alpha\leq1,$ and ... 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

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

A remark on the Liouville problem for stationary Navier-Stokes equations in Lorentz and Morrey spacesMar 02 2019May 24 2019The Liouville problem for the stationary Navier-Stokes equations on the whole space is a challenging open problem who has know several recent contributions. We prove here some Liouville type theorems for these equations provided the velocity field belongs ... 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

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

Spectrum of the Laplacian and the Jacobi operator on rotational cmc hypersurfaces of spheresFeb 19 2019Mar 21 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

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

Bieberbach groups and flat manifolds with finite abelian holonomy from Artin braid groupsMay 13 2019Let $n\geq 3$. In this paper we show that for any finite abelian subgroup $G$ of $S_n$ the crystallographic group $B_n/[P_n,P_n]$ has Bieberbach subgroups $\Gamma_{G}$ with holonomy group $G$. Using this approach we obtain an explicit description of the ... More

Minimal $D=4$ truncations of type IIAAug 01 2019Consistent embeddings are found of the minimal $\mathcal{N} = 2$ and $\mathcal{N} = 3$ gauged supergravities in four dimensions into its maximally supersymmetric, $\mathcal{N} = 8$, counterpart with a dyonic ISO(7) gauging. These minimal truncations retain ... More

Cosmological solutions to polynomial affine gravity in the torsion-free sectorAug 17 2018We find possible cosmological models of the Polynomial Affine Gravity described by connections that are either compatible or not with a metric. When possible, we compare them with those of General Relativity. We show that the set of cosmological vacuum ... More

Cosmological solutions to polynomial affine gravity in the torsion-free sectorAug 17 2018Apr 09 2019We find possible cosmological models of the Polynomial Affine Gravity described by connections that are either compatible or not with a metric. When possible, we compare them with those of General Relativity. We show that the set of cosmological vacuum ... 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.

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

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

Topological effects on string vacuaJan 23 2011We review some topological effects on the construction of string flux-vacua. Specifically we study the effects of brane-flux transitions on the stability of D-branes on a generalized tori compactificaction, the transition that a black hole suffers in ... More

The Initial-Boundary Value Problem in General RelativitySep 03 2010In this article we summarize what is known about the initial-boundary value problem for general relativity and discuss present problems related to it.

Superstring Sigma Model Computations Using the Pure Spinor FormalismAug 12 2008In this thesis are presented two aplications of the sigma model for the superstring in the pure spinor formulation. The first aplication concerns the computation of the one-loop conformal invariance for the type II superstring, resulting in equations ... More

Freed-Witten anomaly in general flux compactificationDec 11 2006May 27 2007Turning on a NS-NS three-form flux in a compact space drives some D-branes to be either Freed-Witten anomalous or unstable to decay into fluxes by the appearance of instantonic branes. By applying T-duality on a toroidal compactification, the NS-flux ... More

Information Security and Quantum Mechanics: Security of Quantum ProtocolsOct 28 2002The problem of security of quantum key protocols is examined. In addition to the distribution of classical keys, the problem of encrypting quantum data and the structure of the operators which perform quantum encryption is studied. It is found that unitary ... More

Merger of vorticity holesOct 14 2010This paper contains background information for a fluid dynamics video submitted to the Gallery of Fluid Motion to be held along with the 63rd Annual Meeting of the American Physical Society's Division of Fluid Dynamics.

Coherent and squeezed states: introductory review of basic notions, properties and generalizationsDec 18 2018A short review of the main properties of coherent and squeezed states is given in introductory form. The efforts are addressed to clarify concepts and notions, including some passages of the history of science, with the aim of facilitating the subject ... More

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

BIMS: Biomedical Information Management SystemMar 23 2013In this paper, we present BIMS (Biomedical Information Management System). BIMS is a software architecture designed to provide a flexible computational framework to manage the information needs of a wide range of biomedical research projects. The main ... 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

An Optimal Plank TheoremJun 10 2019It is shown that for any sequence $v_1,v_2,\dots,v_n$ of unit vectors in a real Hilbert space $H$, there exists a unit vector $v$ in $H$ such that $$|\langle v_k,v \rangle| \geq \sin(\pi/2n)$$ for all $k$. This a sharp version of the plank theorem for ... More

On the index of minimal hypersurfaces of spheresFeb 27 2019Let $M\subset S^{n+1}\subset\mathbb{R}^{n+2}$ be a compact minimal hypersurface of the $n$-dimensional Euclidean unit sphere. Let us denote by $|A|^2$ the square of the norm of the second fundamental form and $J(f)=-\Delta f-nf-|A|^2f$ the stability operator. ... More

Shape and surface anisotropy effects on the hysteresis of ferrimagnetic nanoparticlesApr 15 2003We present the results of Monte Carlo simulations of a model of a single maghemite ferrimagnetic nanoparticle with the aim to clarify the role played by the increased anisotropy at the surface and by the shape (spherical or elliptical) of the particle ... More

Finite-Size and surface effects in maghemite nanoparticles: Monte Carlo simulationsJan 23 2001Finite-size and surface effects in fine particle systems are investigated by Monte Carlo simulation of a model of a $\gamma$-Fe$_2$O$_3$ (maghemite) single particle. Periodic boundary conditions have been used to simulate the bulk properties and the results ... More

On the Hasse principle for quartic hypersurfacesDec 20 2017Apr 24 2019We establish the Hasse principle for smooth projective quartic hypersurfaces of dimension greater than or equal to 28 defined over $\mathbb{Q}$.