Results for "Andrés Aranda"

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The independence number of HH-homogeneous graphs and a classification of MB-homogeneous graphsFeb 08 2019We show that the independence number of a countably infinite HH-homogeneous graph that does not contain the Rado graph as a spanning subgraph is finite and present a classification of MB-homogeneous graphs up to bimorphism-equivalence as a consequence. ... More
Morphism extension classes of countable $L$-colored graphsMay 04 2018In~\cite{Hartman:2014}, Hartman, Hubi\v cka and Ma\v sulovi\'c studied the hierarchy of morphism extension classes for finite $L$-colored graphs, that is, undirected graphs without loops where sets of colors selected from $L$ are assigned to vertices ... More
Ramsey expansions of metrically homogeneous graphsJul 09 2017Dec 28 2017We discuss the Ramsey property, the existence of a stationary independence relation and the coherent extension property for partial isometries (coherent EPPA) for all classes of metrically homogeneous graphs from Cherlin's catalogue, which is conjectured ... More
Completing graphs to metric spacesJun 01 2017Jun 25 2017We prove that certain classes of metrically homogeneous graphs omitting triangles of odd short perimeter as well as triangles of long perimeter have the extension property for partial automorphisms and we describe their Ramsey expansions.
Thin Position for 4-manifoldsMay 22 2018Jan 17 2019Motivated by M. Scharlemann and A. Thompson's definition of thin position of 3-manifolds, we define the width of a Kirby diagram and introduce the notion of thin position of a compact smooth $4-$manifold with connected boundary. We determine all manifolds ... More
Minimal genus four manifoldsJan 28 2019In 2018, M. Chu and S. Tillmann gave a lower bound for the trisection genus of a closed 4-manifold in terms of the Euler characteristic of $M$ and the rank of its fundamental group. We show that given a group $G$, there exist a 4-manifold $M$ with fundamental ... More
Fine gradings on simple exceptional Jordan pairs and triple systemsAug 21 2015We give a classification up to equivalence of the fine group gradings by abelian groups on the Jordan pairs and triple systems of types bi-Cayley and Albert, under the assumption that the base field is algebraically closed of characteristic different ... More
An orbital-free molecular dynamics study of melting in K_20, K_55, K_92, K_142, Rb_55 and Cs_55 clustersMay 22 2000Feb 24 2001The melting-like transition in potasium clusters K_N, with N=20, 55, 92 and 142, is studied by using an orbital-free density-functional constant-energy molecular dynamics simulation method, and compared to previous theoretical results on the melting-like ... More
Melting behavior of large disordered sodium clustersMay 18 2000The melting-like transition in disordered sodium clusters Na_N, with N=92 and 142 is studied by using a first-principles constant-energy molecular dynamics simulation method. Na_142, whose atoms are distributed in two (surface and inner) main shells with ... More
Une remarque à propos de l'équivalence bilipschitzienne entre des ensembles de Delone. (A remark concerning bi-Lipschitz equivalence between Delone sets.)Mar 01 2016Linearly repetitive Delone sets are shown to be rectifiable by a bi-Lipschitz homeomorphisms of the Euclidean space that sends the Delone set to the set of points with integer coordinates.
An L^1 ergodic theorem with values in a nonpositively curved space via a canonical barycenter mapApr 27 2011Dec 20 2011We extend a recent result of Tim Austin (see arXiv:0905.0515) to the L^1 setting, thus providing a general version of the Birkhoff ergodic theorem for functions taking values in nonpositively curved spaces. In this setting, the notion of a Birkhoff sum ... More
Three remarks on one dimensional bi-Lipschitz conjugaciesApr 30 2007We show that bi-Lipschitz conjugacies between non singular one dimensional systems are forced to be smooth, at least in the minimal (and ergodic) case. This is however far from being true in the non minimal case. These results clarify a classical work ... More
Reduction of cocycles and groups of diffeomorphisms of the circleAug 31 2005Mar 01 2011We prove two theorems of reduction of cocycles taking values in the group of diffeomorphisms of the circle. They generalise previous results obtained by the author concerning rigidity for smooth actions on the circle of Kazhdan's groups and higher rank ... More
Comments on "State equation for the three-dimensional system of 'collapsing' hard spheres"Sep 16 2009Nov 09 2009A recent paper [I. Klebanov et al. \emph{Mod. Phys. Lett. B} \textbf{22} (2008) 3153; arXiv:0712.0433] claims that the exact solution of the Percus-Yevick (PY) integral equation for a system of hard spheres plus a step potential is obtained. The aim of ... More
An example concerning the Theory of Levels for codimension-one foliationsSep 06 2008We give an example of a codimension-one foliation which is transversely of class C^1 and which does not satisfy the "Local Minimal Set" property.
The amazing story of a forgotten golden flagOct 04 2015Oct 08 2015We describe the most probable geometric design of the Chilean Independence Flag, which uses the golden ratio in many of its components. We also discuss some related historical aspects.
A remarkable family of left ordered groups: central extensions of Hecke groupsSep 28 2009Oct 23 2010We provide an infinite family of left-ordered groups, all of which have a positive cone that is finitely generated as a semigroup. This family includes the Klein bottle group and the braid group B_3.
Reference and Structure of Software Engineering TheoriesApr 27 2016This paper tries to contribute towards the solution of an important question raised in the SE literature: What is a Software Engineering (SE) specific theory? Which are the main features of a theory that is endemic to SE? In this paper we will use 'theory' ... More
Growth of groups and diffeomorphisms of the intervalAug 18 2005Apr 08 2007We prove that the so called Grigorchuk-Maki group of intermadiate growth can be seen as a group of $C^1$ diffeomorphisms of the interval. On the other hand, we prove that every group of $C^{1+\alpha}$ diffeomorphisms of the interval having subexponential ... More
Sur les rapprochements par conjugaison en dimension 1 et classe C^1Aug 23 2012Nov 08 2013We prove that the space of actions of Z^d by C^1 (orientation-preserving) diffeomorphisms of either the interval or the circle is connected by arcs. This is proved by showing that all such actions can be C^0 conjugated via a 1-parameter family into diffeomorphisms ... More
Extreme values for $S_n(σ,t)$ near the critical lineJul 31 2018Let $S(\sigma,t)=\frac{1}{\pi}\arg\zeta(\sigma+it)$ be the argument of the Riemann zeta function at the point $\sigma+it$ of the critical strip. For $n\geq 1$ and $t>0$ we define $$ S_{n}(\sigma,t) = \int_0^t S_{n-1}(\sigma,\tau)\,d\tau\, + \delta_{n,\sigma\,}, ... More
Ga+, In+ and Tl+ Impurities in Alkali Halide Crystals: Distortion TrendsAug 30 2000A computational study of the doping of alkali halide crystals (AX: A = Na, K; X = Cl, Br) by ns2 cations (Ga+, In+ and Tl+) is presented. Active clusters of increasing size (from 33 to 177 ions) are considered in order to deal with the large scale distortions ... More
Groups of Circle DiffeomorphismsJul 19 2006May 28 2009This book covers many of the recent results on group actions on the circle, with an emphasis in the differentiable case.
Quantitative properties of convex representationsApr 25 2011Jan 28 2012Let $\Gamma$ be a discrete subgroup of $\textrm{PGL}(d,\R)$ and fix some euclidean norm $\|\ \|$ on $\R^d.$ Let $N_\Gamma(t)$ be the number of elements in $\Gamma$ whose operator norm is $\leq t.$ In this article we prove an asymptotic for the growth ... More
Cohomological vertex operatorsJul 26 2016Given a Calabi-Yau manifold and considering the $B$-branes on it as objects in the derived category of coherent sheaves, we identify the vertex operators for strings between two branes with elements of the cohomology groups of Ext sheaves. We define the ... More
On conjugates and the asymptotic distortion of 1-dimensional $C^{1+bv}$ diffeomorphismsNov 14 2018Dec 18 2018We show that a $C^{1+bv}$ circle diffeomorphism with absolutely continuous derivative and irrational rotation number can be conjugated into diffeomorphisms that are $C^{1+bv}$ arbitrary close of the corresponding rotation. This improves a theorem of M.~Herman, ... More
Equivariant branesFeb 06 2015Feb 10 2015Given a Calabi-Yau manifold $X$ acted by a group $G$ and considering the $B$-branes on $X$ as objects in the derived category of coherent sheaves, we give a definition of equivariant branes, which generalizes the concept of equivariant sheaves. We also ... 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
On entropy, regularity and rigidity for convex representations of hyperbolic manifoldsMar 27 2013Dec 18 2014Given a convex representation $\rho:\Gamma\to\textrm{PGL}(d,\mathbb{R})$ of a convex co-compact group $\Gamma$ of $\mathbb{H}^k$ we find upper bounds for the quantity $\alpha h_\rho,$ where $h_\rho$ is the entropy of $\rho$ and $\alpha$ is the H\"older ... More
Note: An exact scaling relation for truncatable free energies of polydisperse hard-sphere mixturesFeb 03 2012Apr 07 2012A theoretical model for polydisperse systems of hard spheres is said to be truncatable when the excess free energy depends on the size distribution through a finite number $K$ of moments. This Note proves an exact scaling relation for truncatable free ... More
Action Integrals and discrete seriesAug 08 2011Let $G$ be a complex semisimple Lie group and ${G}_{\mathbb R}$ a real form that contains a compact Cartan subgroup $T_{\mathbb R}$. Let $\pi$ be a discrete series representation of $G_{\mathbb R}$. We present geometric interpretations in terms of concepts ... More
Invariants under deformation of the actions of topological groupsMay 20 2016Let $\varphi$ and $\varphi'$ be two homotopic actions of the topological group $G$ on the topological space $X$. To an object $A$ in the $G$-equivariant derived category $D_{\varphi}(X)$ of $X$ relative to the action $\varphi$ we associate an object $A'$ ... More
Chemical-Potential Route: A Hidden Percus-Yevick Equation of State for Hard SpheresApr 20 2012Sep 21 2012The chemical potential of a hard-sphere fluid can be expressed in terms of the contact value of the radial distribution function of a solute particle with a diameter varying from zero to that of the solvent particles. Exploiting the explicit knowledge ... More
Solutions of the moment hierarchy in the kinetic theory of Maxwell modelsMar 05 2009Dec 05 2009In the Maxwell interaction model the collision rate is independent of the relative velocity of the colliding pair and, as a consequence, the collisional moments are bilinear combinations of velocity moments of the same or lower order. In general, however, ... More
Groups, orders, and lawsMay 05 2014We discuss the question whether left-orderable groups satisfying a nontrivial law are locally indicable.
On centralizers of interval diffeomorphisms in critical (intermediate) regularitySep 05 2013We extend to the critical (intermediate) regularity several results concerning rigidity for centralizers and group actions on the interval.
On the dynamics of (left) orderable groupsOct 12 2007Feb 16 2010We study left orderable groups by using dynamical methods. We apply these techniques to study the space of orderings of these groups. We show for instance that for the case of (non-Abelian) free groups, this space is homeomorphic to the Cantor set. We ... More
Self-energy renormalization around the flux phase in the $t-J$ model: Possible implications in underdoped cupratesFeb 14 2008The flux phase predicted by the $t-J$ model in the large-N limit exhibits features that make it a candidate for describing the pseudogap regime of cuprates. However certain properties, as for instance the prediction of well defined quasiparticle peaks, ... More
$t-J$ model one-electron renormalizations: high energy features in photoemission experiments of high-$T_c$ cupratesMar 06 2007Recent angle-resolved photoemission experiments in hole doped cuprates reported new and interesting high energy features which may be useful for understanding the electronic properties of these materials. Using a perturbative approach, which allows the ... More
A Characteristic Number of Hamiltonian Bundles over $S^2$Jun 09 2005Dec 16 2005Each loop $\psi$ in the group $\text{Ham}(M)$ of Hamiltonian diffeomorphisms of a symplectic manifold $M$ determines a fibration $E$ on $S^2$, whose coupling class \cite{G-L-S} is denoted by $c$. If $VTE$ is the vertical tangent bundle of $E$, we relate ... More
Continuous families of Hamiltonian torus actionsMay 19 2008We determine conditions under which two Hamiltonian torus actions on a symplectic manifold $M$ are homotopic by a family of Hamiltonian torus actions, when $M$ is a toric manifold and when $M$ is a coadjoint orbit.
A finitely generated, locally indicable group with no faithful action by C^1 diffeomorphisms of the intervalFeb 26 2009According to Thurston's stability theorem, every group of C^1 diffeomorphisms of the closed interval is locally indicable (.e., every finitely generated subgroup factors through Z). We show that, even for finitely generated groups, the converse of this ... More
Evidence for two competing order parameters in underdoped cuprates superconductors from a model analysis of the Fermi-arc effectsNov 10 2009Preformed pairs above $T_c$ and the two-gap scenarios are two main proposals for describing the low doping pseudogap phase of high-$T_c$ cuprates. Very recent angle-resolved photoemission experiments have shown features which were interpreted as evidence ... More
Charge of $D$-branes on singular varietiesNov 19 2018Considering the $D$-branes on a variety $Z$ as the objects of the derived category $D^b(Z)$, we propose a definition for the charge of $D$-branes on not necessarily smooth varieties. We define the charge $Q({\mathcal G})$ of ${\mathcal G}\in D^b(Z)$ as ... More
A note on entire $L$-functionsMay 03 2018In this paper, we exhibit upper and lower bounds with explicit constants for some objects related to entire $L$-functions in the critical strip, under the generalized Riemann hypothesis. The examples include the entire Dirichlet $L$-functions $L(s,\chi)$ ... More
TMI! How Knowledge Platforms Tame the Information Overload and Advance Global Development Through TechnologySep 28 2016Finding reliable data to inform decisions about technology for global development remains a challenge. Easily accessible "Knowledge platforms" are a way to curate and standardize information about technology for development. Three collaborators, Engineering ... More
When the C in CP does not matter: anatomy of CP-half-odd scalars and their Yukawa interactionsAug 31 2016Sep 24 2016We explore the origin and Yukawa interactions of the peculiar CP-half-odd scalars that were recently found in a multi-Higgs model based on an order-4 CP symmetry. We relate the existence of such scalars to the enhanced freedom of defining CP, even beyond ... More
Gradings on tensor products of composition algebras and on the Smirnov algebraDec 28 2018We give classifications of group gradings, up to equivalence and up to isomorphism, on the tensor product of a Cayley algebra $\mathcal{C}$ and a Hurwitz algebra over a field of characteristic different from 2. We also prove that the automorphism group ... More
Non-Newtonian Poiseuille flow of a gas in a pipeJun 05 2000The Bhatnagar-Gross-Krook kinetic model of the Boltzmann equation is solved for the steady cylindrical Poiseuille flow fed by a constant gravity field. The solution is obtained as a perturbation expansion in powers of the field (through fourth order) ... More
Velocity Distribution and Cumulants in the Unsteady Uniform Longitudinal Flow of a Granular GasJul 06 2012Nov 30 2012The uniform longitudinal flow is characterized by a linear longitudinal velocity field $u_x(x,t)=a(t)x$, where $a(t)={a_0}/({1+a_0t})$ is the strain rate, a uniform density $n(t)\propto a(t)$, and a uniform granular temperature $T(t)$. Direct simulation ... More
Collisional rates for the inelastic Maxwell model: application to the divergence of anisotropic high-order velocity moments in the homogeneous cooling stateJul 01 2011May 11 2012The collisional rates associated with the isotropic velocity moments $<V^{2r}>$ and the anisotropic moments $<V^{2r}V_i>$ and $<V^{2r}(V_iV_j-d^{-1}V^2\delta_{ij})>$ are exactly derived in the case of the inelastic Maxwell model as functions of the exponent ... More
Unsteady non-Newtonian hydrodynamics in granular gasesNov 18 2011Feb 07 2012The temporal evolution of a dilute granular gas, both in a compressible flow (uniform longitudinal flow) and in an incompressible flow (uniform shear flow), is investigated by means of the direct simulation Monte Carlo method to solve the Boltzmann equation. ... More
The star cluster frequency throughout the Large Magellanic CloudOct 16 2013We address the issue about the variation of the star cluster frequency (CF) in the Large Magellanic Cloud (LMC) in terms of the cluster spatial distribution. We adopted the LMC regions traced by Harris & Zaritsky (2009) and used an updated version of ... More
The Value of A Statistical Life in Absence of Panel Data: What can we do?Mar 02 2016In this paper I show how reliable estimates of the Value of a Statistical Life (VSL) can be obtained using cross sectional data using Garen's instrumental variable (IV) approach. The increase in the range confidence intervals due to the IV setup can be ... More
ScratchR: Sharing User-generated Programmable MediaJul 05 2015In this paper, I describe a platform for sharing programmable media on the web called ScratchR. As the backbone of an on-line community of creative learners, ScratchR will give members access to an audience and inspirational ideas from each other. ScratchR ... More
Toward categoricity for classes with no maximal modelsJul 15 1997We provide here the first steps toward Classification Theory of Abstract Elementary Classes with no maximal models, plus some mild set theoretical assumptions, when the class is categorical in some lambda greater than its Lowenheim-Skolem number. We study ... More
Describing all bi-orderings on Thompson's group FAug 12 2008Mar 19 2009We describe all possible ways of bi-ordering Thompson group F: its space of bi-orderings is made up of eight isolated points and four canonical copies of the Cantor set.
The quasi-state space of a C*-algebra is a topological quotient of the representation spaceApr 15 2013Jan 28 2015We show that for any C*-algebra $A$, a sufficiently large Hilbert space $H$ and a unit vector $\xi \in H$, the natural application $rep(A:H) \to Q(A)$, $\pi \mapsto \langle \pi(-)\xi,\xi \rangle$ is a topological quotient, where $rep(A:H)$ is the space ... More
Energy Production Rates of Multicomponent Granular Gases of Rough Particles. A Unified View of Hard-Disk and Hard-Sphere SystemsSep 07 2018Granular gas mixtures modeled as systems of inelastic and rough particles, either hard disks on a plane or hard spheres, are considered. Both classes of systems are embedded in a three-dimensional space ($d=3$) but, while in the hard-sphere case the translational ... More
Eigenvalues and Entropy of a Hitchin representationNov 19 2014Dec 18 2014We show that the critical exponent of a representation in the Hitchin component of $PSL(d,\mathbb{R})$ is bounded above, the least upper bound being attained only in the Fuchsian locus. This provides a rigid inequality for the area of a minimal surface ... More
Improved accuracy for time-splitting methods for the numerical solution of parabolic equationsAug 31 2016In this work, we study time-splitting strategies for the numerical approximation of evolutionary reaction-diffusion problems. In particular, we formulate a family of domain decomposition splitting methods that overcomes some typical limitations of classical ... More
Driven and undriven states of multicomponent granular gases of inelastic and rough hard disks or spheresJan 31 2019Starting from a recent derivation of the energy production rates in terms of the number of translational and rotational degrees of freedom, a comparative study on different granular temperatures in gas mixtures of inelastic and rough disks or spheres ... More
A BV-algebra Structure on Hochschild Cohomology of the Group Ring of Finitely Generated Abelian GroupsApr 10 2017We study a Batalin-Vilkovisky algebra structure on the Hochschild cohomology of the group ring of finitely generated abelian groups. The Batalin-Vilkovisky algebra structure for finite abelian groups comes from the fact that the group ring of finite groups ... More
Bounding $S_n(t)$ on the Riemann hypothesisFeb 14 2017Let $S(t) = \tfrac{1}{\pi} \arg \zeta (\frac12 + it)$ be the argument of the Riemann zeta-function at the point $\tfrac12 + it$. For $n \geq 1$ and $t>0$ define its iterates \begin{equation*} S_n(t) = \int_0^t S_{n-1}(\tau) \,{\rm d}\tau\, + \delta_n\,, ... More
Bessel potentials in Ahlfors regular metric spacesJun 26 2015In this paper we define Bessel potentials in Ahlfors regular spaces using a Coifman type approximation of the identity, and show they improve regularity for Lipschitz, Besov and Sobolev-type functions. We prove density and embedding results for the Sobolev ... More
On Newton-Sobolev spacesMay 08 2015Newton-Sobolev spaces, as presented by N. Shanmugalingam, describe a way to extend Sobolev spaces to the metric setting via upper gradients, for metric spaces with `sufficient' paths of finite length. Sometimes, as is the case of parabolic metrics, most ... More
Non-rectifiable Delone sets in SOL and other solvable groupsAug 13 2015Given a lattice $\Gamma \subset SOL$, we show that there is a coarsely dense subset $\mathcal{D} \subset \Gamma$ that is not biLipschitz equivalent to $\Gamma$. We also prove similar results for lattices in certain higher rank abelian-by-abelian groups ... More
The age-metallicity relationship in the Small Magellanic Cloud peripheryMay 20 2015We present results from Washington CT1 photometry for eleven star fields located in the western outskirts of the Small Magellanic Cloud (SMC), which cover angular distances to its centre from 2 up to 13 degrees (~ 2.2 - 13.8 kpc). The colour- magnitude ... More
Large-N expansion based on the Hubbard operator path integral representation and its application to the t-J model II. The case for finite $J$Sep 29 2004We have introduced a new perturbative approach for $t-J-V$ model where Hubbard operators are treated as fundamental objects. Using our vertices and propagators we have developed a controllable large-N expansion to calculate different correlation functions. ... More
Modelling the Uruguayan debt through gaussians modelsAug 01 2015We model bond's price curves corresponding to the sovereign uruguayan debt nominated in USD, as an alternative to the official bond prices publication released by the Central Bank of Uruguay (CBU). Four different gaussian models are fitted, based on historical ... More
The realistic collective nuclear HamiltonianMay 08 1995The residual part of the realistic forces ---obtained after extracting the monopole terms responsible for bulk properties--- is strongly dominated by pairing and quadrupole interactions, with important $\sigma\tau\cdot\sigma \tau$, octupole and hexadecapole ... More
Limb-darkening and exoplanets II: Choosing the Best Law for Optimal Retrieval of Transit ParametersJan 21 2016Jan 28 2016Very precise measurements of exoplanet transit lightcurves both from ground and space based observatories make it now possible to fit the limb-darkening coefficients in the transit-fitting procedure rather than fix them to theoretical values. This strategy ... More
Ultra-recursive sequencesFeb 05 2019We study a new type of sequences whose elements are defined in terms of the position, sign and magnitude of another element of the sequence. The name ultra-recursive comes from the fact that these sequences possess terms that are generated adding either ... More
Rigid isotopy classification of generic rational quintics in $\mathbb{R}\mathbb{P}^{2}$Apr 13 2018In this article we obtain the rigid isotopy classification of generic rational curves of degre $5$ in $\mathbb{R}\mathbb{P}^{2}$. In order to study the rigid isotopy classes of nodal rational curves of degree $5$ in $\mathbb{R}\mathbb{P}^{2}$, we associate ... More
Equilateral $p$-gons in $\mathbb R^d$ and deformed spheres and mod $p$ Fadell-Husseini indexJun 06 2017We introduce the concept of $r$-equilateral $m$-gons. We prove the existence of $r$-equilateral $p$-gons in $\mathbb R^d$ if $r<d$ and the existence of equilateral $p$-gons in the image of continuous injective maps $f:S^d\to \mathbb R^{d+1}$. Our ideas ... More
The small index property for homogeneous models in AECsOct 09 2017We prove a version of a small index property theorem for strong amalgamation classes. Our result builds on an earlier theorem by Lascar and Shelah (in their case, for saturated models of uncountable first-order theories). We then study versions of the ... More
Decomposable Leavitt path algebras for arbitrary graphsMar 16 2016For any field $K$ and for a completely arbitrary graph $E$, we characterize the Leavitt path algebras $L_K(E)$ that are indecomposable (as a direct sum of two-sided ideals) in terms of the underlying graph. When the algebra decomposes, it actually does ... More
Some relations between quantum Turing machines and Turing machinesDec 03 1999Dec 06 1999For quantum Turing machines we present three elements: Its components, its time evolution operator and its local transition function. The components are related with the components of deterministic Turing machines, the time evolution operator is related ... More
A trace theorem for Besov functions in spaces of homogeneous typeJul 31 2015The aim of this paper is to prove a trace theorem for Besov functions in the metric setting, generalizing a known result from A. Jonsson and H. Wallin in the Euclidean case. We show that the trace of a Besov space defined in a `big set' $X$ is another ... More
On the invariant distributions of C^2 circle diffeomorphisms of irrational rotation numberJul 05 2012Sep 17 2012We show that no C^2 circle diffeomorphism of irrational rotation number has invariant 1-distributions other than (scalar multiples of) the invariant measure. We also show that this is false in the C^1 context by giving both minimal and non-minimal examples. ... More
Gâteaux differentiability on non-separable Banach spacesAug 08 2018Oct 21 2018This paper deals with the extension of a classical theorem by R. Phelps on the G\^ateaux differentiability of Lipschitz functions on separable Banach spaces to the non-separable case. The extension of the theorem is not possible for general non-separable ... More
Isomorphismes de graphes en temps quasi-polynomial (d'après Babai et Luks, Weisfeiler-Leman...)Jan 16 2017Oct 12 2017Soient donn\'es deux graphes $\Gamma_1$, $\Gamma_2$ \`a $n$ sommets. Sont-ils isomorphes? S'ils le sont, l'ensemble des isomorphismes de $\Gamma_1$ \`a $\Gamma_2$ peut \^etre identifi\'e avec une classe $H \pi$ du groupe sym\'etrique sur $n$ \'el\'ements. ... More
A geometric path from zero Lyapunov exponents to rotation cocyclesDec 02 2011May 23 2013We consider cocycles of isometries on spaces of nonpositive curvature $H$. We show that the supremum of the drift over all invariant ergodic probability measures equals the infimum of the displacements of continuous sections under the cocycle dynamics. ... More
Time-Symmetric Cellular AutomataDec 03 2010Together with the concept of reversibility, another relevant physical notion is time-symmetry, which expresses that there is no way of distinguishing between backward and forward time directions. This notion, found in physical theories, has been neglected ... More
Minimal data at a given point of space for solutions to certain geometric systemsJan 13 2010We consider a geometrical system of equations for a three dimensional Riemannian manifold. This system of equations has been constructed as to include several physically interesting systems of equations, such as the stationary Einstein vacuum field equations ... More
Limit Models in Metric Abstract Elementary Classes: the Categorical caseApr 25 2013Apr 13 2015We study versions of limit models adapted to the context of *metric abstract elementary classes*. Under categoricity and superstability-like assumptions, we generalize some theorems from [GrVaVi]. We prove criteria for existence and uniqueness of limit ... More
Non-Newtonian Couette-Poiseuille flow of a dilute gasSep 15 2010Jan 20 2011The steady state of a dilute gas enclosed between two infinite parallel plates in relative motion and under the action of a uniform body force parallel to the plates is considered. The Bhatnagar-Gross-Krook model kinetic equation is analytically solved ... More
Multipoint flux mixed finite element methods for slightly compressible flow in porous mediaNov 06 2018In this paper, we consider multipoint flux mixed finite element discretizations for slightly compressible Darcy flow in porous media. The methods are formulated on general meshes composed of triangles, quadrilaterals, tetrahedra or hexahedra. An inexact ... More
Multi-particle critical correlationsDec 14 2014Oct 12 2015We study the role of multi-particle spatial correlations in the appearance of a liquid-vapour critical point. Our analysis is based on the exact infinite hierarchy of equations relating spatial integrals of $(k+1)$-particle correlations to the $k$-particle ... More
Anisotropic Scale Invariant Spacetimes and Black Holes in Zwei-Dreibein GravityJun 18 2014Sep 30 2014We show that Zwei-Dreibein Gravity (ZDG), a bigravity theory recently proposed by Bergshoeff, de Haan, Hohm, Merbis, and Townsend in Phys.Rev.Lett. 111 (2013) 111102, admits exact solutions with anisotropic scale invariance. These type of geometries are ... More
Discovery of a loose star cluster in the Large Magellanic CloudMar 22 2016We present results for an up-to-date uncatalogued star cluster projected towards the Eastern side of the Large Magellanic Cloud (LMC) outer disc. The new object was discovered from a search of loose star cluster in the Magellanic Clouds' (MCs) outskirts ... More
A decreasing step method for strongly oscillating stochastic modelsOct 07 2012Mar 18 2015We propose an algorithm for approximating the solution of a strongly oscillating SDE, that is, a system in which some ergodic state variables evolve quickly with respect to the other variables. The algorithm profits from homogenization results and consists ... More
Quantitative Analysis of Information Leakage in Probabilistic and Nondeterministic SystemsNov 09 2011This thesis addresses the foundational aspects of formal methods for applications in security and in particular in anonymity. More concretely, we develop frameworks for the specification of anonymity properties and propose algorithms for their verification. ... More
Bruck 88 : a young star cluster with an old age resemblance in the outskirts of the Small Magellanic CloudSep 12 2014We present spectroscopic and photometric results for the Small Magellanic Cloud (SMC) cluster Bruck 88. From the comparison of the cluster integrated spectrum with template cluster spectra we found that the Milky Way globular cluster template spectra ... More
An Energy-Efficient MIMO Algorithm with Receive Power ConstraintMay 04 2012We consider the energy-efficiency of Multiple-Input Multiple-Output (MIMO) systems with constrained received power rather than constrained transmit power. A Energy-Efficient Water-Filling (EEWF) algorithm that maximizes the ratio of the transmission rate ... More
Nonadditive hard-sphere fluid mixtures: A simple analytical theoryJul 23 2011Oct 13 2011We construct a non-perturbative fully analytical approximation for the thermodynamics and the structure of nonadditive hard-sphere fluid mixtures. The method essentially lies in a heuristic extension of the Percus-Yevick solution for additive hard spheres. ... More
Simple relationship between the virial-route hypernetted-chain and the compressibility-route Percus--Yevick values of the fourth virial coefficientNov 28 2009Mar 02 2010As is well known, approximate integral equations for liquids, such as the hypernetted chain (HNC) and Percus--Yevick (PY) theories, are in general thermodynamically inconsistent in the sense that the macroscopic properties obtained from the spatial correlation ... More
A Livsic type theorem for germs of analytic diffeomorphismsOct 10 2011We deal with the problem of the validity of Livsic's theorem for cocycles of diffeomorphisms satisfying the orbit periodic obstruction over an hyperbolic dynamics. We give a result in the positive direction for cocycles of germs of analytic diffeomorphisms ... More
A comprehensive photometric study of dynamically evolved small van den Bergh-Hagen open clustersSep 05 2016We present results from Johnson $UBV$, Kron-Cousins $RI$ and Washington $CT_1T_2$ photometries for seven van den Bergh-Hagen (vdBH) open clusters, namely, vdBH\,1, 10, 31, 72, 87, 92, and 118. The high-quality, multi-band photometric data sets were used ... More
Almost reduction and perturbation of matrix cocyclesJan 23 2013Aug 20 2013In this note, we show that if all Lyapunov exponents of a matrix cocycle vanish, then it can be perturbed to become cohomologous to a cocycle taking values in the orthogonal group. This extends a result of Avila, Bochi and Damanik to general base dynamics ... More