Results for "Andrés Aranda"

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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
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
Electroweak scale neutrinos and HiggsesDec 16 2008We present two different models with electroweak scale right-handed neutrinos. One of the models is created under the constraint that any addition to the Standard Model must not introduce new higher scales. The model contains right-handed neutrinos with ... More
Neutrino mixing from the double tetrahedral group T^{\prime}Jul 25 2007Nov 09 2007It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for more general ... More
Models of Flavor with Discrete SymmetriesNov 20 2002In an attempt to understand the observed patterns of lepton and quark masses, models invoking a flavor symmetry $G_f$, under which the Standard Model generations are charged, have been proposed. One particularly successful symmetry, U(2), has been extensively ... More
Thin Position through the lens of trisections of 4-manifoldsMay 22 2018May 19 2019Motivated by M. Scharlemann and A. Thompson's definition of thin position of 3-manifolds, we define the width of a handle decomposition a 4-manifold and introduce the notion of thin position of a compact smooth 4-manifold. We determine all manifolds having ... 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
Asymptotic Enumeration of $I_3$-free DigraphsMay 01 2015We prove that almost all digraphs not embedding an independent set of size 3 consist of two disjoint tournaments, and discuss connections with the theory of homogeneous simple structures.
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
Fine gradings on simple exceptional Jordan pairs and triple systemsAug 21 2015Aug 22 2017We 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
Constraints on realistic Gauge-Higgs unified modelsAug 24 2010Nov 06 2010We investigate the general group structure of gauge-Higgs unified models. We find that a given embedding of the \sm\ gauge group will imply the presence of additional light vectors, except for a small set of special cases, which we determine; the arguments ... More
Generations of Higgs Bosons in Supersymmetric ModelsMay 11 2000Jul 26 2000We examine extensions of the MSSM with more than one generation of Higgs bosons. If one assumes that a symmetry eliminates the tree-level FCNC, then the extra scalar bosons do not acquire VEVs, do not couple to fermions and do not mix with the ordinary ... More
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.
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.
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
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.
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
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
Hamiltonian diffeomorphisms of toric manifoldsJun 09 2005We prove that $\pi_1(\text{Ham}(M))$ contains an infinite cyclic subgroup, where $\text{Ham}(M)$ is the Hamiltonian group of the one point blow up of ${\Bbb C}P^3$. We give a sufficient condition for the group $\pi_1(\text{Ham}(M))$ to contain an infinite ... More
Characteristic number associated to mass linear pairsJun 15 2011Aug 09 2011Let $\Delta$ be a Delzant polytope in ${\mathbb R}^n$ and ${\mathbf b}\in{\mathbb Z}^n$. Let $E$ denote the symplectic fibration over $S^2$ determined by the pair $(\Delta,\,{\mathbf b})$. Under certain hypotheses, we prove the equivalence between the ... More
Cohomological vertex operatorsJul 26 2016Jan 12 2017Given 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
Critical values of moment maps on quantizable manifoldsNov 02 2007Let $M$ be a quantizable symplectic manifold acted on by $T=(S^1)^r$ in a Hamiltonian fashion and $J$ a moment map for this action. Suppose that the set $M^{T}$ of fixed points is discrete and denote by ${\alpha}_{pj}\in{\mathbb Z}^r$ the weights of the ... More
brTPF: Bindings-Restricted Triple Pattern Fragments (Extended Preprint)Aug 29 2016Aug 30 2016The Triple Pattern Fragment (TPF) interface is a recent proposal for reducing server load in Web-based approaches to execute SPARQL queries over public RDF datasets. The price for less overloaded servers is a higher client-side load and a substantial ... 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
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
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.
Lagrangian Floer homology on symplectic blow upsApr 08 2019We show how to compute the Lagrangian Floer homology in the one-point blow up of the proper transform of Lagrangians submanifolds, solely in terms of information of the base manifold. As an example we present an alternative computation of the Lagrangian ... More
A Quick View of Lagrangian Floer HomologyJan 09 2017In this note we present a brief introduction to Lagrangian Floer homology and its relation with the solution of Arnol'd conjecture, on the minimal number of non-degenerate fixed points of a Hamiltonian diffeomorphism. We start with the basic definition ... More
Living Without a Mobile Phone: An AutoethnographyApr 13 2018This paper presents an autoethnography of my experiences living without a mobile phone. What started as an experiment motivated by a personal need to reduce stress, has resulted in two voluntary mobile phone breaks spread over nine years (i.e., 2002-2008 ... More
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
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
Non-Hamiltonian isotopic Lagrangians on the one-point blow-up of CP^2Feb 14 2017We show that two Hamiltonian isotopic Lagrangians in (CP^2,\omega_\textup{FS}) induce two Lagrangian submanifolds in the one-point blow-up (\widetilde{CP}^2,\widetilde{\omega}_\rho) that are not Hamiltonian isotopic. Furthermore, we show that for any ... 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.
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
A Bhatnagar-Gross-Krook-like Model Kinetic Equation for a Granular Gas of Inelastic Rough Hard SpheresJul 05 2010May 25 2011The Boltzmann collision operator for a dilute granular gas of inelastic rough hard spheres is much more intricate than its counterpart for inelastic smooth spheres. Now the one-body distribution function depends not only on the translational velocity ... More
Interplay between polydispersity, inelasticity, and roughness in the freely cooling regime of hard-disk granular gasesMar 12 2018Jul 17 2018A polydisperse granular gas made of inelastic and rough hard disks is considered. Focus is laid on the kinetic-theory derivation of the partial energy production rates and the total cooling rate as functions of the partial densities and temperatures (both ... More
Spanning Class in the Category of BranesApr 11 2018Given a generic anticanonical hypersurface $Y$ of a toric variety determined by a reflexive polytope, we define a line bundle ${\mathcal L}$ on $Y$ that generates a spanning class in the bounded derivative category $D^b(Y)$. From this fact, we deduce ... 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
A characteristic number of bundles determined by mass linear pairsSep 09 2008Nov 13 2008Let $\Delta$ be a Delzant polytope in ${\mathbb R}^n$ and ${\bf b}\in{\mathbb Z}^n$. Let $E$ denote the symplectic fibration over $S^2$ determined by the pair $(\Delta, {\bf b})$. We prove the equivalence between the fact that $(\Delta, {\bf b})$ is a ... 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
Flat Affine and Symplectic Geometries on Lie GroupsOct 04 2017In this paper we exhibit a family of flat left invariant affine structures on the double Lie group of the oscillator Lie group of dimension 4, associated to each solution of classical Yang-Baxter equation given by Boucetta and Medina. On the other hand, ... More
Group actions on 1-manifolds: a list of very concrete open questionsDec 18 2017Apr 20 2018This text focuses on actions on 1-manifolds. We present a (non exhaustive) list of very concrete open questions in the field, each of which is discussed in some detail and complemented with a large list of references, so that a clear panorama on the subject ... More
Wandering domains for diffeomorphisms of the k-torus: a remark on a theorem by Norton and SullivanFeb 08 2017We show that there is no C^{k+1} diffeomorphism of the k-torus which is semiconjugate to a minimal translation and has a wandering domain all of whose iterates are Euclidean balls.
Class of consistent fundamental-measure free energies for hard-sphere mixturesAug 15 2012Oct 05 2012In fundamental-measure theories the bulk excess free-energy density of a hard-sphere fluid mixture is assumed to depend on the partial number densities ${\rho_i}$ only through the four scaled-particle-theory variables ${\xi_\alpha}$, i.e., $\Phi({\rho_i})\to\Phi({\xi_\alpha})$. ... More
Comment on `A general integral identity'Sep 29 2011A simple heuristic proof of an integral identity recently derived (Glasser ML 2011 J. Phys. A: Math. Theor. 44 225202) is presented.
Homogeneous Free Cooling State in Binary Granular Fluids of Inelastic Rough Hard SpheresJul 05 2010May 26 2011In a recent paper [A. Santos, G. M. Kremer, and V. Garz\'o, \emph{Prog. Theor. Phys. Suppl.} \textbf{184}, 31-48 (2010)] the collisional energy production rates associated with the translational and rotational granular temperatures in a granular fluid ... More
Playing with Marbles: Structural and Thermodynamic Properties of Hard-Sphere SystemsOct 21 2013These lecture notes present an overview of equilibrium statistical mechanics of classical fluids, with special applications to the structural and thermodynamic properties of systems made of particles interacting via the hard-sphere potential or closely ... More
Lifting Hamiltonian loops to isotopies in fibrationsFeb 22 2013Let $G$ be a Lie group, $H$ a closed subgroup and $M$ the homogeneous space $G/H$. Each representation $\Psi$ of $H$ determines a $G$-equivariant principal bundle ${\mathcal P}$ on $M$ endowed with a $G$-invariant connection. We consider subgroups ${\mathcal ... 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
Limits on a Light Leptophobic Gauge BosonSep 24 1998We consider the phenomenology of a naturally leptophobic $Z$-prime boson in the 1 to 10 GeV mass range. The $Z$-prime's couplings to leptons arise only via a radiatively-generated kinetic mixing with the $Z$ and photon, and hence are suppressed. We map ... 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
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
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
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
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
Non-Hamiltonian isotopic Lagrangians on the one-point blow-up of CP^2Feb 14 2017Apr 11 2019We show that two Hamiltonian isotopic Lagrangians in (CP^2,\omega_\textup{FS}) induce two Lagrangian submanifolds in the one-point blow-up (\widetilde{CP}^2,\widetilde{\omega}_\rho) that are not Hamiltonian isotopic. Furthermore, we show that for any ... 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
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
Finite-size estimates of Kirkwood-Buff and similar integralsJun 03 2018Dec 03 2018Recently, Kr\"uger and Vlugt [Phys. Rev. E 97, 051301(R) (2018)] have proposed a method to approximate an improper integral $\int_0^\infty \text{d}r\, F(r)$, where $F(r)$ is a given oscillatory function, by a finite-range integral $\int_0^L \text{d}r\, ... 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
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
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
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
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
Dynamical generation of neutrino mass scalesAug 23 2018In this letter we present a simple scenario where the mass scales associated to atmospheric and solar neutrino oscillations are obtained through the dynamical generation of neutrino masses. The main idea is that the two different scales are the result ... 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
Representativity and waist of cable knotsApr 27 2017We study the incompressible surfaces in the exterior of a cable knot and use this to compute the representativity and waist of most cable knots.
When the C in CP does not matter: anatomy of order-4 CP eigenstates and their Yukawa interactionsAug 31 2016Mar 13 2017We explore the origin and Yukawa interactions of the scalars with peculiar CP-properties which 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, ... More
Dynamical generation of neutrino mass scalesAug 23 2018Mar 14 2019In this letter we present a simple scenario where the mass scales associated to atmospheric and solar neutrino oscillations are obtained through the dynamical generation of neutrino masses. The main idea is that the two different scales are the result ... More
Completing graphs to metric spacesJun 01 2017Mar 04 2019We 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.
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.
Pion dispersion relation at finite density and temperatureJul 04 2002Oct 24 2002We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature. We introduce a pion chemical potential to describe the finite pion number density and argue that such description is valid during the hadronic phase ... More
A 3D printed wheel with constant mass and variable moment of inertia for lab and demonstrationJun 30 2017We present a versatile experimental apparatus for exploring rotational motion through the interplay between the moment of inertia, torque and rotational kinetic energy. The heart of this experiment uses a 3D printed wheel along with easily accessible ... More
Stellar density distribution along the minor axis of the Large Magellanic CloudOct 11 2017We studied the spatial distribution of young and old stellar populations along the western half part of the minor axis of the Large Magellanic Cloud (LMC) using Washington MT1 photometry of selected fields, which span a deprojected distance range from ... 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
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 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
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
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
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
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
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
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
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
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
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
Fermi arcs and isotope effect of the magnetic penetration depth in underdoped cupratesFeb 18 2011The isotope coefficient $\beta$ of the magnetic penetration depth in the superconducting state is studied at T=0 for a $d$-CDW and a nodal metal model. Disregarding superconductivity the Fermi surface of the first model possesses arcs whereas the second ... 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
Eigenvalues and Entropy of a Hitchin representationNov 19 2014Feb 13 2017We 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
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
Detection of a diffuse extended halo-like structure around 47 TucAug 21 2017We constructed for the first time a stellar density profile of 47 Tucanae (47 Tuc) out of $\sim$ 5.5 times its tidal radius ($r_t$) using high-quality deep $BV$ photometry. After carefully considering the influence of photometric errors, and Milky Way ... More
An Alternative Derivation of the Analytic Expression of Transmission SpectraAug 16 2018Under some assumptions, an analytic expression for the transmission spectrum can be obtained, which can form the basis of atmospheric retrievals and allows insight on the degeneracies involved. In this Research Note we present an alternative derivation ... More
Local Bures-Wasserstein Transport: A Practical and Fast Mapping ApproximationJun 19 2019Optimal transport (OT)-based methods have a wide range of applications and have attracted a tremendous amount of attention in recent years. However, most of the computational approaches of OT do not learn the underlying transport map. Although some algorithms ... 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