Welington de Melo

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The existence of smooth families of Lorenz maps exhibiting all possible dynamical behavior is established and the structure of the parameter space of these families is described. Institute of Mathematical Sciences, SUNY at Stony Brook, Stony Brook, NY 11794-3651. IMPA, Estrada Dona Castorina 110, 22460-320 Rio de Janeiro, Brazil.
PURPOSE To study the angiographic anatomy of human coronary veins and the possibility of epicardial venous mapping through microelectrode catheters. METHODS We evaluated 30 patients with sustained ventricular tachycardia using a catheter which provided occlusion of the coronary sinus ostium during venous angiography. They were 25 males, 5 females, ages(More)
OBJECTIVE To study the value of epicardial mapping through the coronary venous system in patients with sustained ventricular tachycardia. DESIGN 20 consecutive patients with sustained ventricular tachycardia who were candidates for radiofrequency ablation. SETTING Electrophysiological laboratory. INTERVENTIONS Coronary venous angiography was performed(More)
In this paper we extend M. Lyubich’s recent results on the global hyperbolicity of renormalization of quadratic-like germs to the space of Cr unimodal maps with quadratic critical point. We show that in this space the boundedtype limit sets of the renormalization operator have an invariant hyperbolic structure provided r ≥ 2 + α with α close to one. As an(More)
We prove that two C critical circle maps with the same rotation number of bounded type are C conjugate for some α > 0 provided their successive renormalizations converge together at an exponential rate in the C sense. The number α depends only on the rate of convergence. We also give examples of C∞ critical circle maps with the same rotation number that are(More)
Given a smooth vector field X on a closed orientable d-manifold M , many questions about the dynamics of its induced flow can be studied analyzing the following cohomological equation: LXu = ξ, where ξ is a given real function on M , u : M → R is the solution that we look for (in a certain regularity class) and LX is the Lie derivative in the X direction.(More)