Une résolution élémentaire d'un problème de scission de séparatrices
Une structure symplectique sur R6 avec une sphère lagrangienne plongée et un champ de Liouville complet.
Une théorie de Morse pour les systèmes hamiltoniens convexes
Une transformation générique peut être insérée dans un flot
Une version feuilletée équivariante du théorème de translation de Brouwer
The Brouwer’s plane translation theorem asserts that for a fixed point free orientation preserving homeomorphism f of the plane, every point belongs to a Brouwer line: a proper topological embedding C of R, disjoint from its image and separating f(C) and f–1(C). Suppose that f commutes with the elements of a discrete group G of orientation preserving homeomorphisms acting freely and properly on the plane. We will construct a G-invariant topological foliation of the plane by Brouwer lines. We apply...
Unfolding contracting singular cycles
Uniform attractor for the partly dissipative nonautonomous lattice systems.
Uniform exponential ergodicity of stochastic dissipative systems
We study ergodic properties of stochastic dissipative systems with additive noise. We show that the system is uniformly exponentially ergodic provided the growth of nonlinearity at infinity is faster than linear. The abstract result is applied to the stochastic reaction diffusion equation in with .
Uniform exponential stability of linear almost periodic systems in Banach spaces.
Uniform exponential stability of linear periodic systems in a Banach space.
Uniform foliation associated with the hamiltonian system
Uniform growth of groups acting on Cartan–Hadamard spaces
In this paper we investigate the growth of finitely generated groups. We recall the definition of the algebraic entropy of a group and show that if the group is acting as a discrete subgroup of the isometry group of a Cartan–Hadamard manifold with pinched negative curvature then a Tits alternative is true. More precisely the group is either virtually nilpotent or has a uniform growth bounded below by an explicit constant.
Uniform mixing time for random walk on lamplighter graphs
Suppose that is a finite, connected graph and is a lazy random walk on . The lamplighter chain associated with is the random walk on the wreath product , the graph whose vertices consist of pairs where is a labeling of the vertices of by elements of and is a vertex in . There is an edge between and in if and only if is adjacent to in and for all . In each step, moves from a configuration by updating to using the transition rule of and then sampling both...
Uniform (projective) hyperbolicity or no hyperbolicity : a dichotomy for generic conservative maps
Uniform pseudo-orbit tracing property for homeomorphisms and continuous mappings
We prove that for every nonempty compact manifold of nonzero dimension no self-homeomorphism and no continuous self-mapping has the uniform pseudo-orbit tracing property. Several relevant counterexamples for recently studied hypotheses are indicated.
Uniform stability and semi-stability of motions in dynamical systems on metric spaces
Some stability properties of motions in pseudo-dynamical systems and semi-systems are studied.
Uniform stability of displacement coupled second-order equations.
Uniform stabilization of some damped second order evolution equations with vanishing short memory
We consider a damped abstract second order evolution equation with an additional vanishing damping of Kelvin–Voigt type. Unlike the earlier work by Zuazua and Ervedoza, we do not assume the operator defining the main damping to be bounded. First, using a constructive frequency domain method coupled with a decomposition of frequencies and the introduction of a new variable, we show that if the limit system is exponentially stable, then this evolutionary system is uniformly − with respect to the calibration...
Uniformely distributed orbits of certain flows on homogeneous spaces.
Uniformization of the leaves of a rational vector field
We study the analytic structure of the leaves of a holomorphic foliation by curves on a compact complex manifold. We show that if every leaf is a hyperbolic surface then they can be simultaneously uniformized in a continuous manner. In case the manifold is complex projective space a sufficient condition is that there are no algebraic leaf.