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Results for "Andrés García-Suaza"

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Un-Reduction of Systems of Second-Order Ordinary Differential EquationsJun 24 2016Dec 07 2016In this paper we consider an alternative approach to "un-reduction". This is the process where one associates to a Lagrangian system on a manifold a dynamical system on a principal bundle over that manifold, in such a way that solutions project. We show ... More
Isolated factorizations and their applications in simplicial affine semigroupsApr 03 2018We introduce the concept of isolated factorizations of an element of a commutative monoid and study its properties. We give several bounds for the number of isolated factorizations of simplicial affine semigroups and numerical semigroups. We also generalize ... More
Distribution Regression in Duration Analysis: an Application to Unemployment SpellsApr 12 2019This article proposes estimation and inference procedures for distribution regression models with randomly right-censored data. The proposal generalizes classical duration models to a situation where slope coefficients can vary with the elapsed duration, ... More
Optical Supersymmetry in the Time DomainMar 24 2019Originally emerged within the context of string and quantum field theory, and later fruitfully extrapolated to photonics, the algebraic transformations of quantum-mechanical supersymmetry were conceived in the space realm. Here, we introduce a paradigm ... More
Morse families and Dirac systemsApr 13 2018Dirac structures and Morse families are used to obtain a geometric formalism that unifies most of the scenarios in mechanics (constrained calculus, nonholonomic systems, optimal control theory, higher-order mechanics, etc.), as the examples in the paper ... More
The interplay between Dirac systems, Morse families and InterconnectionFeb 28 2017Apr 16 2018We provide a generalization of the notion of Dirac system by using Morse families to intrinsically embrace the dynamics associated with different physical systems such as constrained variational calculus, optimal control, Lagrangian mechanics, etc., from ... 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
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
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.
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
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.
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
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 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
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
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
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
A machine learned classifier for RR Lyrae in the VVV surveyOct 18 2016Variable stars of RR Lyrae type are a prime tool to obtain distances to old stellar populations in the Milky Way, and one of the main aims of the Vista Variables in the Via Lactea (VVV) near-infrared survey is to use them to map the structure of the Galactic ... 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
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
On permanents of Sylvester Hadamard matricesNov 11 2013It is well-known that the evaluation of the permanent of an arbitrary $(-1,1)$-matrix is a formidable problem. Ryser's formula is one of the fastest known general algorithms for computing permanents. In this paper, Ryser's formula has been rewritten for ... More
Percolation for the stable marriage of Poisson and Lebesgue with random appetitesSep 29 2009Apr 15 2014Let $\Xi$ be a set of centers chosen according to a Poisson point process in $\mathbb R^d$. Consider the allocation of $\mathbb R^d$ to $\Xi$ which is stable in the sense of the Gale-Shapley marriage problem, with the additional feature that every center ... 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
Chemical Vapor Deposition Growth of Boron-Carbon-Nitrogen layers from Methylamine Borane Thermolysis ProductsFeb 20 2019This work investigates the growth of B-C-N layers by chemical vapor deposition using methylamine borane (MeAB) as single-source precursor. MeAB has been synthesized and characterized, paying particular attention to the analysis of its thermolysis products, ... More
Extensions of finite quantum groups by finite groupsAug 26 2006Mar 27 2008We give a necessary and sufficient condition for two Hopf algebras presented as central extensions to be isomorphic, in a suitable setting. We then study the question of isomorphism between the Hopf algebras constructed in 0707.0070v1 as quantum subgroups ... 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
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
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
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
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
Negative Prices in Network Pricing GamesApr 18 2019In a Stackelberg network pricing game, a leader sets prices for a given subset of edges so as to maximize profit, after which one or multiple followers choose a shortest path from their source to sink. We study the counter-intuitive phenomenon that the ... 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
Non-adiabatic entropy production for non-Markov dynamicsMay 16 2012Sep 06 2012We extend the definition of non-adiabatic entropy production given for Markovian systems in [M. Esposito and C. Van den Broeck, Phys. Rev. Lett. 104 090601, (2010)], to arbitrary non-Markov ergodic dynamics. We also introduce a notion of stability characterizing ... More
Generic pointed quartic curves in $\mathbb{R}\mathbb{P}^{2}$ and uninodal dessinsApr 13 2018In this article we obtain a rigid isotopy classification of generic pointed quartic curves $(A,p)$ in $\mathbb{R}\mathbb{P}^{2}$ by studying the combinatorial properties of dessins. The dessins are real versions, proposed by S. Orevkov, of Grothendieck's ... More
Decoupling mixed finite elements on hierarchical triangular grids for parabolic problemsFeb 09 2017In this paper, we propose a numerical method for the solution of time-dependent flow problems in mixed form. Such problems can be efficiently approximated on hierarchical grids, obtained from an unstructured coarse triangulation by using a regular refinement ... More
O-asymptotic classes of finite structuresOct 09 2014Mar 18 2018In this paper we introduce the concept of O-asymptotic classes of finite structures, melding ideas coming from 1-dimensional asymptotic classes and o-minimality. The results we present here include a cell-decomposition result for O-asymptotic classes ... More
Un-reduction of systems of second-order ordinary differential equationsJun 24 2016In this paper we consider an alternative approach to "un-reduction". This is the process where one associates to a Lagrangian system on a manifold a dynamical system on a principal bundle over that manifold, in such a way that solutions project. We show ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type III. Semisimple classes in PSL(n,q)Jun 22 2015Jun 29 2015We show that Nichols algebras of most simple Yetter-Drinfeld modules over the projective special linear group over a finite field, corresponding to semisimple orbits, have infinite dimension. We introduce a new criterium to determine when a conjugacy ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type IV. Unipotent classes in Chevalley and Steinberg groupsDec 23 2016We show that all unipotent classes in finite simple Chevalley or Steinberg groups, different from PSL_n(q) and PSp_{2n}(q), collapse (i.e. are never the support of a finite-dimensional Nichols algebra), with a possible exception on one class of involutions ... More
A primitive associated to the Cantor-Bendixson derivative on the real lineMay 02 2016We consider the class of compact countable subsets of the real numbers $\mathbb{R}$. By using an appropriate partition, up to homeomorphism, of this class we give a detailed proof of a result shown by S. Mazurkiewicz and W. Sierpinski related to the cardinality ... More
O-asymptotic classes of finite structuresOct 09 2014In this paper we introduce the concept of O-asymptotic classes of finite structures, melding ideas coming from 1-dimensional asymptotic classes and o-minimality. The results we present here include a cell-decomposition result for O-asymptotic classes ... More
Countable ordinal spaces and compact countable subsets of a metric spaceFeb 22 2018Jul 27 2018We show in detail that every compact countable subset of a metric space is homeomorphic to a countable ordinal number, which extends a result given by Mazurkiewicz and Sierpinski for finite-dimensional Euclidean spaces. In order to achieve this goal, ... More
Presence-absence estimation in audio recordings of tropical frog communitiesJan 08 2019One non-invasive way to study frog communities is by analyzing long-term samples of acoustic material containing calls. This immense task has been optimized by the development of Machine Learning tools to extract ecological information. We explored a ... More
Completion of premetric spacesAug 05 2018We present a method for completing a premetric space, in the sense introduced by F. Richman in the context of constructive Mathematics without countable choice.
Compactification of a diagonal action on the product of CAT(-1) spacesNov 25 2016Let $X$ be a proper, non-compact CAT(-1) space, and $\Gamma$ a discrete cocompact subgroup of the isometries of $X$. We compactify the diagonal action of $\Gamma$ on $X \times X$ considering a domain of the horofunction boundary with respect to the maximum ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type I. Non-semisimple classes in PSL(n,q)Dec 21 2013Jul 01 2014We show that Nichols algebras of most simple Yetter-Drinfeld modules over the projective special linear group over a finite field, corresponding to non-semisimple orbits, have infinite dimension. We spell out a new criterium to show that a rack collapses. ... More
Hidden invariance of the free classical particleJun 07 1993Mar 12 1994A formalism describing the dynamics of classical and quantum systems from a group theoretical point of view is presented. We apply it to the simple example of the classical free particle. The Galileo group $G$ is the symmetry group of the free equations ... More
Estimating reducible stochastic differential equations by conversion to a least-squares problemOct 16 2017Jun 23 2018Stochastic differential equations (SDEs) are increasingly used in longitudinal data analysis, compartmental models, growth modelling, and other applications in a number of disciplines. Parameter estimation, however, currently requires specialized software ... More
Duration of local violations of the second law of thermodynamics along single trajectories in phase spaceDec 04 2012Feb 03 2014We define the {\it violation fraction} $\nu$ as the cumulative fraction of time that the entropy change is negative during single realizations of processes in phase space. This quantity depends both on the number of degrees of freedom $N$ and the duration ... More
Symmetry for the duration of entropy-consuming intervalsMar 10 2014Apr 28 2014We introduce the violation fraction $\upsilon$ as the cumulative fraction of time that a mesoscopic system spends consuming entropy at a single trajectory in phase space. We show that the fluctuations of this quantity are described in terms of a symmetry ... More
Matrix models for classical groups and Toeplitz$\pm $Hankel minors with applications to Chern-Simons theory and fermionic modelsJan 25 2019We study matrix integration over the classical Lie groups $U(N),Sp(2N),O(2N)$ and $O(2N+1)$, using symmetric function theory and the equivalent formulation in terms of determinants and minors of Toeplitz$\pm$Hankel matrices. We establish a number of factorizations ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type III. Semisimple classes in PSL(n,q)Jun 22 2015Mar 12 2018We show that Nichols algebras of most simple Yetter-Drinfeld modules over the projective special linear group over a finite field, corresponding to semisimple orbits, have infinite dimension. We introduce a new criterium to determine when a conjugacy ... More
Routh reduction for first-order field theoriesJul 10 2018Nov 13 2018We present a reduction theory for first order Lagrangian field theories which takes into account the conservation of momenta. The relation between the solutions of the original problem with a prescribed value of the momentum and the solutions of the reduced ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type V. Mixed classes in Chevalley and Steinberg groupsDec 30 2018Jan 29 2019We show that all classes that are neither semisimple nor unipotent in finite simple Chevalley or Steinberg groups different from $PSL_n(q)$ collapse (i.e. are never the support of a finite-dimensional Nichols algebra). As a consequence, we prove that ... More
Finite-dimensional pointed Hopf algebras over finite simple groups of Lie type II. Unipotent classes in symplectic groupsDec 23 2014We show that Nichols algebras of most simple Yetter-Drinfeld modules over the projective symplectic linear group over a finite field, corresponding to unipotent orbits, have infinite dimension. We give a criterium to deal with unipotent classes of general ... More
Simultaneous Edit and Imputation for Household Data with Structural ZerosApr 14 2018Sep 11 2018Multivariate categorical data nested within households often include reported values that fail edit constraints---for example, a participating household reports a child's age as older than his biological parent's age---as well as missing values. Generally, ... More
Energy loss as the origin of an universal scaling law of the elliptic flowSep 13 2016It is shown that the excellent scaling of the elliptic flow found for all centralities, species and energies from RHIC to the LHC for $p_{T}$ less than the saturation momentum is a consequence of the energy lost by a parton interacting with the color ... More
Understanding Chatbot-mediated Task ManagementFeb 09 2018Effective task management is essential to successful team collaboration. While the past decade has seen considerable innovation in systems that track and manage group tasks, these innovations have typically been outside of the principal communication ... More
Understanding and enhancing superconductivity in FeSe/STO by quantum size effectsJun 30 2016Nov 24 2016Superconductivity in one-atom-layer iron selenide (FeSe) on a strontium titanate (STO) substrate is enhanced by almost an order of magnitude with respect to bulk FeSe. There is recent experimental evidence suggesting that this enhancement persists in ... More
Understanding and enhancing superconductivity in FeSe/STO by quantum size effectsJun 30 2016Superconductivity in one-atom-layer iron selenide (FeSe) on a strontium titanate (STO) substrate is enhanced by almost an order of magnitude with respect to bulk FeSe. There is recent experimental evidence suggesting that this enhancement persists in ... More
Routh reduction and the class of magnetic Lagrangian systemsMar 15 2012Jun 08 2012In this paper, some new aspects related to Routh reduction of Lagrangian systems with symmetry are discussed. The main result of this paper is the introduction of a new concept of transformation that is applicable to systems obtained after Routh reduction ... More
Towards the solution of some fundamental questions concerning group actions on the circle and codimension-one foliationsDec 15 2013Sep 07 2014We consider finitely generated groups of real-analytic circle diffeomorphisms. We show that if such a group admits an exceptional minimal set (i.e., a minimal invariant Cantor set), then its Lebesgue measure is zero; moreover, there are only finitely ... More
Relation between the usual and the entanglement temperature, in a simple quantum systemJul 02 2015We develop a thermodynamical theory to describe the behavior of the entanglement between a single two-level atom with a single mode of the electromagnetic field. The resonant Jaynes-Cummings model is used to study both the entanglement thermodynamics, ... More
A new characterization of Conrad's property for group orderings, with applicationsJan 07 2009Jan 18 2009We provide a pure algebraic version of the dynamical characterization of Conrad's property. This approach allows dealing with general group actions on totally ordered spaces. As an application, we give a new and somehow constructive proof of a theorem ... More
On the question of ergodicity for minimal group actions on the circleJun 11 2008This work is devoted to the study of minimal, smooth actions of finitely generated groups on the circle. We provide a sufficient condition for such an action to be ergodic (with respect to the Lebesgue measure), and we illustrate this condition by studying ... More
Switched latent force models for reverse-engineering transcriptional regulation in gene expression dataNov 23 2015Oct 25 2017To survive environmental conditions, cells transcribe their response activities into encoded mRNA sequences in order to produce certain amounts of protein concentrations. The external conditions are mapped into the cell through the activation of special ... More
An Empirical Study of Customer Spillover Learning about Service QualityJul 20 2016"Spillover" learning is defined as customers' learning about the quality of a service (or product) from their previous experiences with similar yet not identical services. In this paper, we propose a novel, parsimonious and general Bayesian hierarchical ... More
A possible hypercomputational quantum algorithmJun 18 2004Jun 07 2005The term `hypermachine' denotes any data processing device (theoretical or that can be implemented) capable of carrying out tasks that cannot be performed by a Turing machine. We present a possible quantum algorithm for a classically non-computable decision ... More
Graph isomorphisms in quasi-polynomial timeOct 12 2017Let us be given two graphs $\Gamma_1$, $\Gamma_2$ of $n$ vertices. Are they isomorphic? If they are, the set of isomorphisms from $\Gamma_1$ to $\Gamma_2$ can be identified with a coset $H\cdot\pi$ inside the symmetric group on $n$ elements. How do we ... More
Pair Correlation Estimates for the Zeros of the Zeta-Function via Semidefinite ProgrammingOct 20 2018In this paper we study the distribution of the non-trivial zeros of the zeta-function $\zeta(s)$ (and other L-functions) under Montgomery's pair correlation approach. We use semidefinite programming to improve the asymptotic bounds for $N^*(T)$, $N_d(T)$ ... More
Entanglement through qubit motion and the dynamical Casimir effectDec 20 2018We explore the interplay between acceleration radiation and the dynamical Casimir effect (DCE) in the field of superconducting quantum technologies, analyzing the generation of entanglement between two qubits by means of the DCE in several states of qubit ... More
Numerical Simulations of a Possible Hypercomputational Quantum AlgorithmApr 05 2005The hypercomputers compute functions or numbers, or more generally solve problems or carry out tasks, that cannot be computed or solved by a Turing machine. Several numerical simulations of a possible hypercomputational algorithm based on quantum computations ... More
Quantum hypercomputation based on the dynamical algebra su(1,1)Feb 09 2006Feb 14 2006An adaptation of Kieu's hypercomputational quantum algorithm (KHQA) is presented. The method that was used was to replace the Weyl-Heisenberg algebra by other dynamical algebra of low dimension that admits infinite-dimensional irreducible representations ... More
Symmetry in Software SynthesisApr 21 2017With the surge of multi- and manycores, much research has focused on algorithms for mapping and scheduling on these complex platforms. Large classes of these algorithms face scalability problems. This is why diverse methods are commonly used for reducing ... More
Are primordial black holes produced by entropy perturbations in single field inflationary models?Apr 16 2019We show that in single field inflationary models the super-horizon evolution of curvature perturbations on comoving slices $\mathcal{R}$, which can cause the production of primordial black holes (PBH), is not due to entropy perturbations but to a fast ... More
Extra-tidal structures around the Gaia Sausage candidate globular cluster NGC6779 (M56)Feb 15 2019We present results on the stellar density radial profile of the outer regions of NGC6779, a Milky Way globular cluster recently proposed as a candidate member of the Gaia Sausage structure, a merger remnant of a massive dwarf galaxy with the Milky Way. ... More
Marginal and Irrelevant Disorder in Einstein-Maxwell backgroundsDec 01 2015Jan 15 2016We study analytically the effect of a weak random chemical potential of zero average in an Einstein-Maxwell background. For uncorrelated disorder this perturbation is relevant however we show that it can become marginal or even irrelevant by tuning disorder ... More
Combined effect of thermal and quantum fluctuations in superconducting nanostructures: a path integral approachSep 20 2011We study the combined effect of thermal and quantum fluctuations in a zero dimensional superconductor. By using path integral techniques, we obtain novel expressions for the partition function and the superconducting order parameter which include both ... More
Conductivity and entanglement entropy of high dimensional holographic superconductorsFeb 12 2015Jan 13 2016We investigate the dependence of the conductivity and the entanglement entropy on the space-time dimensionality $d$ in two holographic superconductors: one dual to a quantum critical point with spontaneous symmetry breaking, and the other modeled by a ... More
Size effects in superconducting thin films coupled to a substrateNov 17 2013Jan 13 2016Recent experimental advances in surface science have made it possible to track the evolution of superconductivity in films as the thickness enters the nanoscale region where it is expected that the substrate plays an important role. Here, we put forward ... More
Interplay of classical and "quantum" capacitance in a one dimensional array of Josephson junctionsDec 11 2013Even in the absence of Coulomb interactions phase fluctuations induced by quantum size effects become increasingly important in superconducting nano-structures as the mean level spacing becomes comparable with the bulk superconducting gap. Here we study ... More
Many-Body Localization in a finite-range Sachdev-Ye-Kitaev modelJan 10 2018We study the level statistics of a generalized Sachdev-Ye-Kitaev (SYK) model with two-body and one-body random interactions of finite range by exact diagonalization. Tuning the range of the one-body term, while keeping the two-body interaction sufficiently ... More
Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gasJun 08 2015Axions are well motivated particles proposed in an extension of the SM as a solution to the strong CP problem. Also, there is the category of Axion-Like Particles (ALPs) which appear in extensions of the SM and share the same phenomenology of the axion. ... More
Time dependent quantum scattering theory on complete manifolds with a corner of codimension 2Oct 19 2012Sep 23 2015We show the existence and orthogonality of wave operators naturally associated to a compatible Laplacian on a complete manifold with a corner of codimension 2. In fact, we prove asymptotic completeness i.e. that the image of these wave operators is equal ... More
Absence of singular continuous spectrum for some geometric LaplaciansOct 19 2012We provide two examples of spectral analysis techniques of Schroedinger operators applied to geometric Laplacians. In particular we show how to adapt the method of analytic dilation to Laplacians on complete manifolds with corners of codimension 2 finding ... More
Measuring Cultural Dynamics Through the Eurovision Song ContestJan 14 2013May 10 2013Measuring culture and its dynamics through surveys has important limitations, but the emerging field of computational social science allows us to overcome them by analyzing large-scale datasets. In this article, we study cultural dynamics through the ... More
Higgs bundles and higher Teichmüller spacesJan 25 2019This paper is a survey on the role of Higgs bundle theory in the study of higher Teichm\"uller spaces. Recall that the Teichm\"uller space of a compact surface can be identified with a certain connected component of the moduli space of representations ... More
About the Geometric Solution to the Problems of Dark EnergyNov 19 2010Feb 06 2011In this paper is proposed a geometric solution to the dark energy, assuming that the space can be divided into regions of size $\sim L_{p}$ and energy $\sim E_{p}$. Significantly this assumption generate a energy density similar to the energy density ... More
Degenerate Hessian structures on radiant manifoldsMar 02 2015Sep 29 2017We present a rigorous mathematical treatment of Ruppeiner geometry, by considering degenerate Hessian metrics defined on radiant manifolds. A manifold $M$ is said to be radiant if it is endowed with a symmetric, flat connection $\bar\nabla$ and a global ... More
Exact Solutions for Restricted Incompressible Navier--Stokes Equations with Dirichlet Boundary ConditionsJul 28 2017Mar 21 2019In this paper it is exposed how to obtain a relation that have to be hold for all free divergent velocity fields that evolve according to Navier--Stokes equations. However, checking the violation of this relation requires a huge computational effort. ... More
Actions on products of CAT(-1) spacesSep 21 2018We show that for $X$ a proper $\mathrm{CAT}(-1)$ space there is a maximal open subset of the horofunction compactification of $X\times X$ with respect to the maximum metric that compactifies the diagonal action of an infinite quasi-convex group of the ... More
Some results on translating solitons of the mean curvature flowJan 27 2016In this article we prove two non-existence results for translating solitons of the mean curvature flow (translators for short) in $\mathbb{R}^{m+1}$. We also obtain an upper bound to the maximum height that a compact embedded translator in $\mathbb{R}^{3}$ ... More
A new characterisation of groups amongst monoidsJun 08 2016We prove that a monoid $M$ is a group if and only if, in the category of monoids, all points over $M$ are strong. This sharpens and greatly simplifies a result of Montoli, Rodelo and Van der Linden which characterises groups amongst monoids as the protomodular ... More
Extensions of $\frak{sl}_2$ by generalized derivations and Hom-Lie algebra structures on simple Lie algebrasMar 08 2019Mar 13 2019The purpose of this paper is to show that there are Hom-Lie algebra structures on $\mathfrak{sl}_2(\mathbb{F}) \oplus \mathbb{F}D$, where $D$ is a special type of generalized derivation of $\mathfrak{sl}_2(\mathbb{F})$, and $\mathbb{F}$ is an algebraically ... More
A 2D field theory equivalent to 3D gravity with no cosmological constantMar 14 2013In (2+1) space-time dimensions the Einstein theory of gravity has no local degrees of freedom. In fact, in the presence of a negative cosmological term, it is described by a (1+1) dimensional theory living on its boundary: Liouville theory. It is invariant ... More
Extended Charged Events and Chern-Simons CouplingsAug 08 2011Recently, the concept of dynamical extended charged events has been introduced, and it has been argued that they should play as central a role as that played by particles or ordinary branes. In this article we show that in the presence of a Chern-Simons ... More
Boundary stress tensor and asymptotically AdS3 non-Einstein spaces at the chiral pointAug 01 2011Aug 05 2011Chiral gravity admits asymptotically AdS3 solutions that are not locally equivalent to AdS3; meaning that solutions do exist which, while obeying the strong boundary conditions usually imposed in General Relativity, happen not to be Einstein spaces. In ... More
Type Soundness for Path PolymorphismJan 13 2016Apr 28 2016Path polymorphism is the ability to define functions that can operate uniformly over arbitrary recursively specified data structures. Its essence is captured by patterns of the form $x\,y$ which decompose a compound data structure into its parts. Typing ... More