Results for "Gonzalo Gutierrez"

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Hydrogen bonds and asymmetrical heat diffusion in a-Helices. A Computational AnalysisMay 22 2015In this work, we report the heat rectifying capability of a-helices. Using molecular dynamics simulations we show an increased thermal diffusivity in the C-Terminal to N-Terminal direction of propagation. The origin of this effect seems to be a function ... More
Carlos Grandjot. Drei Jahrzehnte der Mathematik in Chile: 1930-1960Oct 12 2014Carlos Grandjot (1900-1979) was a German mathematician, doctorate from G\"ottingen, who moved to Chile in 1929 and developed there his life and career. He was influential in the development of Chilean mathematics during the period 1930 to 1960. This article ... More
A Self-Index on Block TreesJun 21 2016The Block Tree is a recently proposed data structure that reaches compression close to Lempel-Ziv while supporting efficient direct access to text substrings. In this paper we show how a self-index can be built on top of a Block Tree so that it provides ... More
On an identification of the Lipschitz-free spaces over subsets of $\mathbb{R}^{n}$Mar 13 2017In this short note, we develop a method for identifying the spaces $Lip_{0}(U)$ for every nonempty open convex $U$ of $\mathbb{R}^{n}$ and $n\in\mathbb{N}$. Moreover, we show that $\mathcal{F}(U)$ is identified with a quotient of $L^{1}(U;\mathbb{R}^{n})$. ... More
Ground States are generically a Periodic OrbitJul 01 2013Dec 29 2018We prove that for an expanding transformation the maximizing measures of a generic Lipschitz function are supported on a single periodic orbit.
A characterization of the rational normal curveSep 07 2007We give a characterization of the rational normal curve in terms of the rank function associated to a curve.
On $C^r-$closing for flows on 2-manifoldsNov 23 1999For some full measure subset B of the set of iet's (i.e. interval exchange transformations) the following is satisfied: Let X be a $C^r$, $1\le r\le \infty$, vector field, with finitely many singularities, on a compact orientable surface M. Given a nontrivial ... More
Inclusive production of X$\rightarrow b\bar{b}$ plus a recoil for the LHC Run-IIApr 05 2016This letter presents a study of the inclusive production of X$\rightarrow b\bar{b}$ plus a recoil, using simulated samples of $pp$ collisions at $\sqrt{s}=14$ TeV for an integrated luminosity in the range between 30 fb$^{-1}$ to 3 ab$^{-1}$. The case ... More
Logics and Games for True ConcurrencyNov 04 2010We study the underlying mathematical properties of various partial order models of concurrency based on transition systems, Petri nets, and event structures, and show that the concurrent behaviour of these systems can be captured in a uniform way by two ... More
Conferences vs. Journals: Throwing the baby out with the bath water?Mar 06 2015Criticism of the conference model should be put in context. Evidences suggest that the essential features of this model have emerged as responses to challenges posed by current trends of scientific research and the impact of the new techno-economic paradigm, ... More
Characteristic dynamics near two coalescing eigenvalues incorporating continuum threshold effectsSep 25 2016It has been reported in the literature that the survival probability $P(t)$ near an exceptional point where two eigenstates coalesce should generally exhibit an evolution $P(t) \sim t^2 e^{-\Gamma t}$, in which $\Gamma$ is the decay rate of the coalesced ... More
Well-posedness of a cross-diffusion population model with nonlocal diffusionMay 10 2019We prove the existence and uniqueness of solution of a nonlocal cross-diffusion competitive population model for two species. The model may be considered as a version, or even an approximation, of the paradigmatic Shigesada-Kawasaki-Teramoto cross-diffusion ... More
Loop Quantum Gravity and Ultra High Energy Cosmic RaysAug 27 2002Jan 31 2003There are two main sets of data for the observed spectrum of ultra high energy cosmic rays (those cosmic rays with energies greater than $\sim 4 \times 10^{18}$ eV), the High Resolution Fly's Eye (HiRes) collaboration group observations, which seem to ... More
Interior regularity for fractional systemsApr 15 2016We study the regularity of solutions of elliptic fractional systems of order 2s, $s \in (0, 1)$, where the right hand side f depends on a nonlocal gradient and has the same scaling properties as the nonlocal operator. Under some structural conditions ... More
Black branes in flux compactificationsJun 17 2013Aug 07 2013We construct charged black branes in type IIA flux compactifications that are dual to (2+1)-dimensional field theories at finite density. The internal space is a general Calabi-Yau manifold with fluxes, with internal dimensions much smaller than the AdS ... More
Is there a maximum observable redshift in an open universe?Oct 10 2000An estimate of the maximum observable redshift is obtained using only t_{0} approximately equal to (14+- 3)10^{9}years, H_{0} approximately equal to 65 +- 10Km\sec^{-1}Mpc^{-1}(t_{0}H_{0} approximately equal to 0.91 +- 0.08/0.18) assuming \Lambda approximately ... More
Optimal Dynamic Sequence RepresentationsJun 29 2012Feb 01 2013We describe a data structure that supports access, rank and select queries, as well as symbol insertions and deletions, on a string $S[1,n]$ over alphabet $[1..\sigma]$ in time $O(\lg n/\lg\lg n)$, which is optimal even on binary sequences and in the ... More
A microscopic theory of gauge mediationApr 12 2011Aug 15 2011We construct models of indirect gauge mediation where the dynamics responsible for breaking supersymmetry simultaneously generates a weakly coupled subsector of messengers. This provides a microscopic realization of messenger gauge mediation where the ... More
Gauge theories from D7-branes over vanishing 4-cyclesOct 19 2010We study quiver gauge theories on D7-branes wrapped over vanishing holomorphic 4-cycles. We investigate how to incorporate O7-planes and/or flavor D7-branes, which are necessary to cancel anomalies. These theories are chiral, preserve four supercharges ... More
Cosmology in Palatini theories of gravityJul 19 2012We discuss recent results on the cosmology of extended theories of gravity formulated in the Palatini approach, i.e., assuming that metric and connection are independent fields. In particular, we focus on the attempts to explain the cosmic speedup with ... More
Palatini approach to bouncing cosmologies and DSR-like effectsNov 23 2011It is shown that a quadratic gravitational Lagrangian in the Palatini formulation is able to capture different aspects of quantum gravity phenomenology in a single framework. In particular, in this theory field excitations propagating with different energy-densities ... More
The quantum Bernoulli mapOct 24 2011The classical Bernoulli and baker maps are two simple models of deterministic chaos. On the level of ensembles, it has been shown that the time evolution operator for these maps admits generalized spectral representations in terms of decaying eigenfunctions. ... More
On Compressing Permutations and Adaptive SortingAug 22 2011Previous compact representations of permutations have focused on adding a small index on top of the plain data $<\pi(1), \pi(2),...\pi(n)>$, in order to efficiently support the application of the inverse or the iterated permutation. In this paper we initiate ... More
Absence of Binding in the Nelson ModelOct 30 2016We prove that two non-relativistic nucleons interacting with a massless meson field (a massless Nelson model with two particles) do not bind when a sufficiently strong Coulomb repulsion between the nucleons is added to the Hamiltonian, an explicit estimate ... More
Gauge-Higgs unification on the braneJan 18 2007From the quantum field theory point of view, matter and gauge fields are generally expected to be localised around branes or topological defects occurring in extra dimensions. Here I discuss a simple scenario where, by starting with a five dimensional ... More
Confining the Electroweak Model to a BraneMay 19 2005Feb 22 2006We introduce a simple scenario where, by starting with a five-dimensional SU(3) gauge theory, we end up with several 4-D parallel branes with localized fermions and gauge fields. Similar to the split fermion scenario, the confinement of fermions is generated ... More
Error Probability Bounds for Gaussian Channels under Maximal and Average Power ConstraintsJul 06 2019This paper studies the performance of block coding on an additive white Gaussian noise channel under different power limitations at the transmitter. Lower bounds are presented for the minimum error probability of codes satisfying maximal and average power ... More
A Method for Clustering Web Attacks Using Edit DistanceApr 03 2003Cluster analysis often serves as the initial step in the process of data classification. In this paper, the problem of clustering different length input data is considered. The edit distance as the minimum number of elementary edit operations needed to ... More
A topological equivalence result for a family of nonlinear difference systems having generalized exponential dichotomyDec 31 2014Aug 28 2015We obtain sufficient conditions ensuring the topological equivalence of two perturbed difference linear systems whose linear part has a property of generalized exponential dichotomy. When the exponential dichotomy is verified, we obtain a strongly and ... More
Differentiability of Palmer's linearization Theorem and converse result for density functionsJun 20 2014Nov 07 2014We study differentiability properties in a particular case of the Palmer's linearization Theorem, which states the existence of an homeomorphism $H$ between the solutions of a linear ODE system having exponential dichotomy and a quasilinear system. Indeed, ... More
Soap bubbles and isoperimetric regions in the product of a closed manifold with Euclidean spaceDec 21 2013For any closed Riemannian manifold $X$ we prove that large isoperimetric regions in $X\times{\mathbb R}^n$ are of the form $X\times$(Euclidean ball). We prove that if $X$ has non-negative Ricci curvature then the only soap bubbles enclosing a large volume ... More
Shimura correspondence for level $p^2$ and the central values of $L$-series IIMay 27 2010Mar 29 2014Given a Hecke eigenform $f$ of weight $2$ and square-free level $N$, by the work of Kohnen, there is a unique weight $3/2$ modular form of level $4N$ mapping to $f$ under the Shimura correspondence. Furthermore, by the work of Waldspurger the Fourier ... More
Top-Higgs Yukawa Coupling Measurement at a Linear e+e- ColliderOct 12 1999A feasibility study of the measurement of the top-Higgs Yukawa coupling at a future linear e+e- collider operating at sqrt(s)=800 GeV is presented. As compared to previous existing studies, much effort has been put in a ``realistic simulation'' by including ... More
Generalised spin structures on 2-dimensional orbifoldsApr 12 2010Generalised spin structures, or r-spin structures, on a 2-dimensional orbifold \Sigma are r-fold fibrewise connected coverings (also called r-th roots) of its unit tangent bundle ST\Sigma. We investigate such structures on hyperbolic orbifolds. The conditions ... More
A Spectral Dichotomy Version of the Nonautonomous Markus--Yamabe ConjectureMar 12 2018In this article we introduce a nonautonomous version of the Markus--Yamabe conjecture from an exponential dichotomy spectrum point of view. We prove the validity of this conjecture for the scalar and triangular case. Additionally we show that the origin ... More
Anomalous Goos-Hänchen shift in the Floquet scattering of Dirac fermionsJul 09 2019We study the inelastic scattering of two-dimensional massless Dirac fermions by an inhomogeneous time-dependent driving field. As a physical realization we consider a monolayer graphene normally illuminated with a circularly polarized laser of frequency ... More
Time-Reversal Symmetry and Arrow of Time in Quantum Mechanics of Open SystemsMar 12 2019It is one of the most important and long-standing issues of physics to derive the irreversibility out of a time-reversal symmetric equation of motion. The present paper considers the breaking of the time-reversal symmetry in open quantum systems and the ... More
Time-Reversal Symmetry and Arrow of Time in Quantum Mechanics of Open SystemsMar 12 2019Apr 09 2019It is one of the most important and long-standing issues of physics to derive the irreversibility out of a time-reversal symmetric equation of motion. The present paper considers the breaking of the time-reversal symmetry in open quantum systems and the ... More
A priori and a posteriori error estimates for a virtual element spectral analysis for the elasticity equationsDec 14 2017Dec 19 2017We present a priori and a posteriori error analysis of a Virtual Element Method (VEM) to approximate the vibration frequencies and modes of an elastic solid. We analyze a variational formulation relying only on the solid displacement and propose an $H^1({\Omega})$-conforming ... More
An explicit Waldspurger formula for Hilbert modular forms IIDec 30 2018We describe a construction of preimages for the Shimura map on Hilbert modular forms using generalized theta series, and give an explicit Waldspurger type formula relating their Fourier coefficients to central values of twisted $L$-functions. This formula ... More
Transversely holomorphic flows and contact circles on spherical 3-manifoldsOct 29 2015Apr 12 2016Motivated by the moduli theory of taut contact circles on spherical 3-manifolds, we relate taut contact circles to transversely holomorphic flows. We give an elementary survey of such 1-dimensional foliations from a topological viewpoint. We describe ... More
Majorization of quantum polarization distributionsOct 03 2016Majorization provides a rather powerful partial-order classification of probability distributions depending only on the spread of the statistics, and not on the actual numerical values of the variable being described. We propose to apply majorization ... More
Models of spherical shells as sources of Majumdar-Papapetrou type spacetimesAug 05 2016By starting with a seed Newtonian potential-density pair we construct relativistic thick spherical shell models for a Majumdar-Papapetrou type conformastatic spacetime. As simple example, we considerer a family of Plummer type relativistic spherical shells. ... More
Models of spherical shells as sources of Majumdar-Papapetrou type spacetimesAug 05 2016Feb 03 2017By starting with a seed Newtonian potential-density pair we construct relativistic thick spherical shell models for a Majumdar-Papapetrou type conformastatic spacetime. As a simple example, we consider a family of Plummer-Hernquist type relativistic spherical ... More
Contact spheres and hyperkähler geometryOct 10 2001Mar 28 2008A taut contact sphere on a 3-manifold is a linear 2-sphere of contact forms, all defining the same volume form. In the present paper we completely determine the moduli of taut contact spheres on compact left-quotients of SU(2) (the only closed manifolds ... More
Computing central values of twisted L-series: the case of composite levelsJul 01 2006Let f be a newform of weight two and composite level N. We show how to compute weight 3/2 modular forms "associated" to f whose Fourier coefficients are related to the central values of quadratic twists (real and imaginary) of f. We will focus on examples ... More
On the Asymmetry of Vibrational Energy FlowApr 16 2016A simple model to predict the directionality of vibrational energy flow at molecular level is presented. This model is based on a vibrational energy propagation analysis using ab intio molecular dynamics and the Fukui function and local softness reactivity ... More
Electronic structure of crystalline binary and ternary Cd-Te-O compoundsMay 30 2004The electronic structure of crystalline CdTe, CdO, $\alpha$-TeO$_2$, CdTeO$_3$ and Cd$_3$TeO$_6$ is studied by means of first principles calculations. The band structure, total and partial density of states, and charge densities are presented. For $\alpha$-TeO$_2$ ... More
The Optimal Form of Distribution Networks Applied to the Kidney and LungAug 10 2007A model is proposed to minimize the total volume of the main distribution networks of fluids in relation to the organ form. The minimization analysis shows that the overall exterior form of distribution networks is a modified ellipsoid, a geometric form ... More
The Markus-Yamabe Conjecture for Differentiable vector fields of R^2Nov 21 2003Aug 13 2004(a) Let X=(f,g) be a differentiable map in the plane (not necessarily C^1) and let Spec(X) be the set of (complex) eigenvalues of the derivative DX(p) when p varies in R^2. If, for some \epsilon>0, the set Spec(X) is disjoint of [0,\epsilon) then X is ... More
On Cr-closing for flows on orientable and non-orientable 2-manifoldsDec 13 2006Aug 07 2007We provide an affirmative answer to the Cr Closing Lemma, r>1, for a large class of flows defined on every closed surface.
Optical Counterparts of Ultra Luminous X-ray SourcesFeb 09 2006We present optical identification and characterization of counterparts of four objects previously catalogued as ultra-luminous X-ray sources. The objects were selected from the Colbert & Ptak (2002) catalogue. The optical counterparts are identified as ... More
Computation of unirational fieldsApr 10 2008One of the main contributions which Volker Weispfenning made to mathematics is related to Groebner bases theory. In this paper we present an algorithm for computing all algebraic intermediate subfields in a separably generated unirational field extension ... More
On Peixoto's Conjecture for Flows on Non-orientable 2-ManifoldsDec 02 2003Jan 31 2006Let M be a non-orientable compact 2-manifold of genus 4. Then there exists a family of quasi-minimal, Kupka-Smale smooth vector fields X_r in M, depending smoothly on 0<=r<e, such that, for some flow box V in M of X_0, and for all 0<=r,v<e, (1) X_r restricted ... More
The most distant compact groupsJul 14 2011We present photometric and spectroscopic observations of the members of three previously cataloged compact group (CG) candidates at redshifts z>0.3. These confirm spectroscopic redshifts compatible with being gravitationally bound structures at redshifts ... More
An Introduction to the Inverse Quantum Bound State Problem in One DimensionAug 22 2013A technique to reconstruct one-dimensional, reflectionless potentials and the associated quantum wave functions starting from a finite number of known energy spectra is discussed. The method is demonstrated using spectra that scale like the lowest energy ... More
On the mu and lambda invariants of the logarithmic class groupFeb 12 2018Dec 07 2018Let $\ell$ be a rational prime number. Assuming the Gross-Kuz'min conjecture along a $\Zl$-extension $K\_{\infty}$ of a number field $K$, we show that there exist integers $\mut$, $\lat$ and $\widetilde{\nu}$ such that the exponent $\tilde{e}\_{n}$ of ... More
Induced Riemannian structures on null hypersurfacesJul 04 2012Jul 25 2017Given a null hypersurface $L$ of a Lorentzian manifold, we construct a Riemannian metric $\widetilde{g}$ on it from a fixed transverse vector field $\zeta$. We study the relationship between the ambient Lorentzian manifold, the Riemannian manifold $(L,\widetilde{g})$ ... More
A generating set for the automorphism group of a graph product of abelian groupsNov 03 2009We find a set of generators for the automorphism group of a graph product of finitely generated abelian groups entirely from a certain labeled graph. In addition, we find generators for the important subgroup of star-automorphisms defined in [7]. We follow ... More
On an extension of the Blaschke-Santalo inequalityOct 31 2007Let $K$ be a convex body and $K^\circ$ its polar body. Call $\phi(K)=\frac{1}{|K||K^\circ|}\int_K\int_{K^\circ}< x,y>^2 dxdy$. It is conjectured that $\phi(K)$ is maximum when $K$ is the euclidean ball. In particular this statement implies the Blaschke-Santalo ... More
Lightlike hypersurfaces in Lorentzian manifoldsJul 04 2012Given a lightlike hypersurface $L$ in a Lorentzian manifold and $\zeta$ a vector field which is not tangent to it, we construct a lightlike section, a screen distribution and a Riemannian metric $\widetilde{g}$ on $L$. We study the relationship between ... More
Site Model of Allometric Scaling and Fractal Distribution Networks of OrgansApr 27 2004At the basic geometric level, the distribution networks carrying vital materials in living organisms, and the units such as the nephrons and alveoli, form a scaling structure named here the site model. This unified view of the allometry of the kidney ... More
Distribution networks and the optimal form of the kidney and lungDec 07 2005A model is proposed to minimize the total volume of the main distribution networks of fluids in organs such as the kidney and the lung. A consequence of the minimization analysis is that the optimal overall form of the organs is a modified ellipsoid. ... More
The estimation of the noise in cosmic microwave background anisotropy experimentsFeb 21 1997Even the most sensitive cosmic microwave background anisotropy experiments have signal to noise ratios <=5, so that an accurate determination of the properties of the cosmological signal requires a careful assessment of the experimental noise. Most of ... More
On decomposition of tame polynomials and rational functionsApr 10 2008In this paper we present algorithmic considerations and theoretical results about the relation between the orders of certain groups associated to the components of a polynomial and the order of the group that corresponds to the polynomial, proving it ... More
On Ritt's decomposition Theorem in the case of finite fieldsMar 27 2008Apr 10 2008A classical theorem by Ritt states that all the complete decomposition chains of a univariate polynomial satisfying a certain tameness condition have the same length. In this paper we present our conclusions about the generalization of these theorem in ... More
About the isotropy constant of random convex setsJul 11 2007Let K be the symmetric convex hull of m independent random vectors uniformly distributed on the unit sphere of R^n. We prove that, for every $\delta>0$, the isotropy constant of K is bounded by a constant $c(\delta)$ with high probability, provided that ... More
Rigidity of graph products of abelian groupsOct 13 2007We show that if $G$ is a group and $G$ has a graph-product decomposition with finitely-generated abelian vertex groups, then $G$ has two canonical decompositions as a graph product of groups: a unique decomposition in which each vertex group is a directly-indecomposable ... More
Leading Charm in Hadron-Nucleus Interactions in the Intrinsic Charm ModelAug 03 1998Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in $\Sigma^- A$ interactions at 330 GeV with the WA89 detector disagree with fusion ... More
The Off-Axis Galaxy Cluster Merger Abell 115Dec 17 2003Oct 12 2004We have used a 50.4 ksec Chandra obsffervation to examine the galaxy cluster Abell 115 (z=0.1971). The X-ray surface brightness distribution shows a merger of 2 sub-clusters with substantial off-axis motion. The northern sub-cluster moves toward the southwest ... More
The multiset semantics of SPARQL patternsOct 14 2016The paper determines the algebraic and logic structure of the multiset semantics of the core patterns of SPARQL. We prove that the fragment formed by AND, UNION, OPTIONAL, FILTER, MINUS and SELECT corresponds precisely to both, the intuitive multiset ... More
Negation in SPARQLMar 19 2016Jun 06 2016This paper presents a thorough study of negation in SPARQL. The types of negation supported in SPARQL are identified and their main features discussed. Then, we study the expressive power of the corresponding negation operators. At this point, we identify ... More
An algorithm for determining equations for superelliptic curves with minimal invariantsApr 18 2019Let $k$ be a number field and $\mathcal O_k$ its ring of integers. For any superelliptic curve $\mathcal X$, defined over $\mathcal O_k$, and equation $z^m y^{d-m} = f(x, y)$ we give an algorithm which determines a minimal model over $\mathcal O_k$ in ... More
Asymptotic Analysis of a Viscoelastic Flexural Shell ModelOct 31 2017We consider a family of linearly viscoelastic shells with thickness $2\varepsilon$, clamped along a portion of their lateral face, all having the same middle surface $S=\mathbf{\theta}(\bar{\omega})\subset\mathbb{R}^3$, where $\omega\subset\mathbb{R}^2$ ... More
On the Justification of Viscoelastic Generalized Membrane EquationsJul 31 2018Apr 26 2019We consider a family of linearly viscoelastic shells with thickness $2\varepsilon$, clamped along a portion of their lateral face, all having the same middle surface $S=\mathbf{\theta}(\bar{\omega})\subset \mathbb{R}^3$, where $\omega\subset\mathbb{R}^2$ ... More
On the law of motion in Special RelativityFeb 19 2003Newton's law of motion relative to an inertial frame ("the laboratory") for a particle subject to a force acting at a certain time may be interpreted in either of two ways: (1) The force acting on the particle during an infinitesimal time imparts to the ... More
The Leavitt path algebras of generalized Cayley graphsOct 17 2013Let $n$ be a positive integer. For each $0\leq j \leq n-1$ we let $C_n^{j}$ denote Cayley graph for the cyclic group ${\mathbb Z}_n $ with respect to the subset $\{1, j\}$. For any such pair $(n,j)$ we compute the size of the Grothendieck group of the ... More
Spin and Center of Mass in Axially Symmetric Einstein-Maxwell SpacetimesFeb 27 2012We give a definition and derive the equations of motion for the center of mass and angular momentum of an axially symmetric, isolated system that emits gravitational and electromagnetic radiation. A central feature of this formulation is the use of Newman-Unti ... More
Sound Speed of Primordial Fluctuations in Supergravity InflationJan 20 2016Oct 11 2016We study the realization of slow-roll inflation in $\mathcal N = 1$ supergravities where inflation is the result of the evolution of a single chiral field. When there is only one flat direction in field space, it is possible to derive a single-field effective ... More
Consistently violating the non-Gaussian consistency relationFeb 11 2015Dec 21 2015Non-attractor models of inflation are characterized by the super-horizon evolution of curvature perturbations, introducing a violation of the non-Gaussian consistency relation between the bispectrum's squeezed limit and the power spectrum's spectral index. ... More
Nonlinear Gravity Theories in the Metric and Palatini FormalismsMar 22 2004May 03 2004We study nonlinear gravity theories in both the metric and the Palatini (metric-affine) formalisms. The nonlinear character of the gravity lagrangian in the metric formalism causes the appearance of a scalar source of matter in Einstein's equations that ... More
Estimates of disjoint sequences in Banach lattices and R.I. function spacesApr 29 2004We introduce UDSp-property (resp. UDTq-property) in Banach lattices as the property that every normalized disjoint sequence has a subsequence with an upper p-estimate (resp. lower q-estimate). In the case of rearrangement invariant spaces, the relationships ... More
Regularity for solutions of non local, non symmetric equationsJun 29 2011Jun 26 2012We study the regularity for solutions of fully nonlinear integro differential equations with respect to nonsymmetric kernels. More precisely, we assume that our operator is elliptic with respect to a family of integro differential linear operators where ... More
Some calculus with extensive quantities: wave equationMar 24 2003We take some first steps in providing a synthetic theory of distributions. In particular, we are interested in the use of distribution theory as foundation, not just as tool, in the study of the wave equation.
A Strong Scalar Weak Gravity Conjecture and Some ImplicationsMar 21 2019We propose a new version of the scalar Weak Gravity Conjecture (WGC) which would apply to any scalar field coupled to quantum gravity. For a single scalar it is given by the differential constraint $V''\leq (2V'''^2/V''-V'''')M_{\text{p}}^2$. It corresponds ... More
Origin of the anomalous semiconducting behaviour in dense lithiumFeb 25 2018May 21 2018Experimentally, it is known that lithium undergoes a metal to semiconductor transition at about 80 GPA and a reentrant semiconductor to metal transition near 120 GPA. This unusual behaviour has been attributed to the formation of high-pressure electrides ... More
The Importance of Social and Government Learning in Ex Ante Policy EvaluationFeb 01 2019We provide two methodological insights on \emph{ex ante} policy evaluation for macro models of economic development. First, we show that the problems of parameter instability and lack of behavioral constancy can be overcome by considering learning dynamics. ... More
On the Justification of Viscoelastic Generalized Membrane EquationsJul 31 2018We consider a family of linearly viscoelastic shells with thickness $2\varepsilon$, clamped along a portion of their lateral face, all having the same middle surface $S=\mathbf{\theta}(\bar{\omega})\subset \mathbb{R}^3$, where $\omega\subset\mathbb{R}^2$ ... More
Localization effects induced by decoherence in superpositions of many-spin quantum statesMar 23 2011Sep 17 2011The spurious interaction of quantum systems with their environment known as decoherence leads, as a function of time, to a decay of coherence of superposition states. Since the interactions between system and environment are local, they can also cause ... More
Quantifying the Coherence of Development Policy PrioritiesFeb 01 2019Over the last 30 years, the concept of policy coherence for development has received especial attention among academics, practitioners and international organizations. However, its quantification and measurement remain elusive. To address this challenge, ... More
Does Better Governance Guarantee Less Corruption? Evidence of Loss in Effectiveness of the Rule of LawFeb 01 2019Corruption is an endemic societal problem with profound implications in the development of nations. In combating this issue, cross-national evidence supporting the effectiveness of the rule of law seems at odds with poorly realized outcomes from reforms ... More
Work function tuning of graphene oxide by using cesium applied to low work function tethersJun 25 2019Low Work Function Tethers (LWT) is long conductors with a segment coated with a material that has loosely-bounded electrons. Unlike a standard bare tether equipped with an active electron emitter, LWTs close the electrical circuit (cathodic contact) with ... More
Null Decomposition of TreesAug 02 2017Let $T$ be a tree, we show that the null space of the adjacency matrix of $T$ has relevant information about the structure of $T$. We introduce the Null Decomposition of trees, and use it in order to get formulas for independence number and matching number ... More
Aspherical lens design and imagingJul 29 2015Mar 04 2016We design freeform lenses refracting an arbitrarily given incident field into a given fixed direction. In the near field case, we study the existence of lenses refracting a given bright object into a predefined image. We also analyze the existence of ... More
On the existence of dichromatic single element lensesJan 22 2018Due to dispersion, light with different wavelengths, or colors, is refracted at different angles. Our purpose is to determine when is it possible to design a lens made of a single homogeneous material so that it refracts light superposition of two colors ... More
$Ξ^-$ and $Ω$ Distributions in Hadron-Nucleus InteractionsFeb 13 2003Strange baryons have long been known to exhibit a leading particle effect. A recent comparison of $\Xi^-$ production in $\pi^-$, $n$, and $\Sigma^-$ interactions with nuclei show this effect clearly. These data are supplemented by earlier measurements ... More
The reflector problem and the inverse square lawMay 30 2013We introduce a model to design reflectors that take into account the inverse square law for radiation. We prove existence of solutions, both in the near and far field cases, when the input and output energies are prescribed.
Asymmetries Between Strange and Antistrange Particle Production in Pion-Proton InteractionsJul 05 2001Feb 14 2002Recent measurements of the asymmetries between Feynman $x$ distributions of strange and antistrange hadrons in $\pi^- A$ interactions show a strong effect as a function of $x_F$. We calculate strange hadron production in the context of the intrinsic model ... More
Formation and Evolution of Structures in the UniverseMay 04 2004We summarize our work on structures in different stages of aggregation, and spanning a wide range in redshift. We emphasize our work on high resdhift clusters. This comprises the analysis of ~7 square degrees using deep images with several broad-band ... More
A counterrotating central component in NGC 5728Mar 17 1999We present a detailed study of the stellar kinematics in the barred galaxy NGC 5728 based on I-band photometry and long-slit spectroscopic observations in the region of the near-IR Ca II triplet. The analysis of the stellar line-of-sight velocity distribution ... More