We show the existence of families of hip-hop solutions in the equal-mass 2N -body problem which are close to highly eccentric planar elliptic homographic motions of 2N bodies plus small perpendicular non-harmonic oscillations. By... more
In this paper we prescribe a fourth order curvature -the Q-curvature on the standard n-sphere, n 5. Under flatness condition of order β, n -4 β < n near each critical point of the prescribed Q-curvature function, we characterize the... more
This paper is devoted to the existence of contact forms of prescribed Webster scalar curvature on a 3-dimensional CR compact manifold locally conformally CR equivalent to the unit sphere S 3 of C 2 . Due to Kazdan-Warner type... more
Topologies of invariant manifolds and optimal trajectories are investigated in stochastic continuous systems and maps. A topological method is introduced that simplifies the solution of boundary value problems: The activation energy is... more
It is known that the Mycielski graph can be generalized to obtain an infinite family of 4-chromatic graphs with no short odd cycles. The first proof of this result, due to Stiebitz, applied the topological method of Lov~sz. The proof... more
O objetivo principal deste trabalho consiste em mostrar a existˆencia de m etricas com curva- tura de Ricci positiva na classe conforme de uma m etrica Riemanniana com curvatura escalar positiva em variedades compactas de dimens ao 3 e 4.... more
We segment the stabilization region in a simulation of a lifted jet flame based on its topology induced by the Y OH field. Our segmentation method yields regions that correspond to the flame base and to potential auto-ignition kernels. We... more
A series of hydrazide-hydrazones, based on a series of 4-substituted benzoic acid, were synthesized, and their structures were elucidated and screened for the antituberculosis activity against Mycobacterium tuberculosis H37Rv with the... more
These lecture notes are mainly devoted to a K-theory proof of the Atiyah-Singer index theorem. Some applications of the K-theory to noncommutative topology are also given.
These are the notes of five lectures given at the Summer School Geometric and Topological Methods for Quantum Field Theory, held in Villa de Leyva (Colombia), July 2-20, 2007. The lectures are meant for graduate or almost graduate... more
We give lower bounds on the number of periodic trajectories in strictly convex smooth billiards in R m+1 for m ≥ 3. For plane billiards (when m = 1) such bounds were obtained by G. Birkhoff in the 1920's. Our proof is based on topological... more
These are the notes of five lectures given at the Summer School Geometric and Topological Methods for Quantum Field Theory, held in Villa de Leyva (Colombia), July 2-20, 2007. The lectures are meant for graduate or almost graduate... more
These are the notes of five lectures given at the Summer School Geometric and Topological Methods for Quantum Field Theory, held in Villa de Leyva (Colombia), July 2-20, 2007. The lectures are meant for graduate or almost graduate... more
Naturally derived antimicrobial peptides have been an area of great interest because of high selectivity against bacterial targets over host cells and the limited development of bacterial resistance to these molecules throughout... more
A series of hydrazide-hydrazones, based on a series of 4-substituted benzoic acid, were synthesized, and their structures were elucidated and screened for the antituberculosis activity against Mycobacterium tuberculosis H37Rv with the... more
We show that the S 1-equivariant Yamabe invariant of the 3-sphere, endowed with the Hopf action, is equal to the (non-equivariant) Yamabe invariant of the 3-sphere. More generally, we establish a topological upper bound for the S... more
A spatially heterogeneous reaction-diffusion system modelling predator-prey interaction is studied, where the interaction is governed by a Holling type II functional response. Existence of multiple positive steady states and global... more
In previous works we proposed a method for the study of systems with one renewable resource. The separation of the individual and the group parameters and the discretization of time led us to scalar linear functional equations with shift.... more
In this paper, we analyse the polyharmonic equation (−) m u = a(x)u + f (x) |u| 2 * −2 u in a bounded smooth domain with homogeneous Dirichlet conditions on the boundary and critical exponents. We will obtain a relationship between the... more
This paper aims at establishing the existence and uniqueness of solutions for a nonstandard variationalhemivariational inequality. The solutions of this inequality are discussed in a subset K of a reflexive Banach space X. Firstly, we... more
Algebraic topology brings a powerful framework for studying the figure and structure of topological spaces using algebraic methods. Nowadays, the area of data analysis has seen an emerging interest in applying Algebraic topology... more
The chemical bond evolution in the isomerization of XNO X s H, Cl has been investigated by a topological method based on the Catastrophe Theory. The different domains of structural stability occurring along the reaction path have been... more
A series of hydrazide-hydrazones, based on a series of 4-substituted benzoic acid, were synthesized, and their structures were elucidated and screened for the antituberculosis activity against Mycobacterium tuberculosis H37Rv with the... more
This paper is devoted to the problem of prescribing the scalar curvature under zero boundary conditions. Using dynamical and topological methods involving the study of critical points at infinity of the associated variational problem, we... more
A complex of incompressible surfaces in a handlebody is constructed so that it contains, as a subcomplex, the complex of curves of the boundary of the handlebody. For genus 2 handlebodies, the group of automorphisms of this complex is... more
We apply topological methods to obtain global continuation results for harmonic solutions of some periodically perturbed ordinary differential equations on a k-dimensional differentiable manifold M ⊆ R m. We assume that M is globally... more
We try to investigate in this paper the behaviour of a non-linear perturbation of the p-Laplace operator, under a variation of p. Where we can show conservation of the degree under suitable assumption on the non-linearity.
In this paper an algebraic method, which shares all the advantages of the topological methods and allows us to obtain the same results as the standard algebraic method with a substantial reduction in memory and cpu requirements, is... more
We continue our analysis of geodesics in quenched, random Riemannian environments. In this article, we prove that a geodesic with randomly chosen initial conditions is almost surely not minimizing. To do this, we show that a minimizing... more
For a smooth manifold X with boundary we construct a semigroupoid T − X and a continuous field C * r (T − X) of C *-algebras which extend Connes' construction of the tangent groupoid. We show the asymptotic multiplicativity of-scaled... more
For a smooth manifold X with boundary we construct a semigroupoid T − X and a continuous field C * r (T − X) of C *-algebras which extend Connes' construction of the tangent groupoid. We show the asymptotic multiplicativity of-scaled... more
Starting from the canonical symmetroid S(G) associated with a groupoid G, the issue of describing dynamical maps in the groupoidal approach to Quantum Mechanics is addressed. After inducing a Haar measure on the canonical symmetroid S(G),... more
Differential chains are a proper subspace of de Rham currents given as an inductive limit of Banach spaces endowed with a geometrically defined strong topology. Boundary is a continuous operator, as are operators that dualize to Hodge... more
In this paper we prove new theorems on critical point theory based on the weak Ekeland's variational principle.
In this paper, we show the existence of a sequences of eigenvalues for an operator homogenous at the infinity, we give his variational formulation and we establish the simplicity of all eigenvalues in the case N = 1. Finally we study the... more
We present properties of sets of invariant lines for Brouwer homeomorphisms which are not necessarily embeddable in a flow. Using such lines we describe the structure of equivalence classes of the codivergency relation. We also obtain a... more
Basic tools of Riemannian geometry In this chapter, we will briefly describe the foundations of Riemannian geometry for readers who are unfamiliar with the subject. Our choice of material is made in view of applications to Carleman... more
Analog to the classical result of Kazdan-Warner for the existence of solutions to the prescribed Gaussian curvature equation on compact 2-manifolds without boundary, it is widely known that if $(M,g_0)$ is a closed 4-manifold with zero... more
In this paper, we are interested in entire, non-trivial, non-negative solutions and/or entire, positive solutions to the simplest models of polyharmonic equations with power-type nonlinearity ∆ m u = ±u α in R n with n 1, m 1, and α ∈ R.... more
Milne-like spacetimes are a class of hyperbolic FLRW spacetimes which admit continuous spacetime extensions through the big bang, τ = 0. The existence of the extension follows from writing the metric in conformal Minkowskian coordinates... more
In this paper, by using the topological degree theory for multivalued maps and the bounding function method, we give sufficient conditions for the existence of solutions to a nonlocal problem of differential complementarity systems. An... more
Let Gr be a component of the Grassmann manifold of a C *-algebra, presented as the unitary orbit of a given orthogonal projection Gr = Gr(P). There are several natural connections in this manifold, and we first show that they all agree... more
We study the optimal control of systems for a class of nonlinear hemivariational inequalities which are in the form of evolutionary inclusions involving Clarke's generalized gradient. The control variables are introduced both in the... more
In this paper, we study a class of partial differential variational inequalities. A general stability result for the partial differential variational inequality is provided in the case the perturbed parameters are involved in both the... more
The goal of the paper is to study a generalized elliptic inclusion problem driven by a nonhomogeneous partial differential operator with the Dirichlet boundary condition and a convection multivalued term. An existence theorem for positive... more
In this paper, combining Kirillov's method of orbits with Connes' method in Differential Geometry, we study the so-called MD(5,3C)-foliations, i.e. the orbit foliations of the co-adjoint action of MD(5,3C)-groups. First, we classify... more