1,721,602 research outputs found
A variational approach to the study of the existence of invariant lagrangian graphs
No full textThis paper surveys some recent results by the author and some collaborators, on the existence of invariant Lagrangian graphs for Tonelli Hamiltcmian systems
Prime riflessioni su Agenda 2000: quale futuro per la politica agricola dell'Unione Europea?
No full textPrime riflessioni su Agenda 2000: quale futuro per la politica agricola dell'Unione Europea?
No full textLa piccola azienda e la nuova politica agraricola dell'Unione uropea. Problemi economici e strutturali.
No full textAction-minimizing Methods in Hamiltonian Dynamics: An Introduction to Aubry-Mather Theory
No full textJohn Mather’s seminal works in Hamiltonian dynamics represent some of the most important contributions to our understanding of the complex balance between stable and unstable motions in classical mechanics. His novel approach—known as Aubry-Mather theory—singles out the existence of special orbits and invariant measures of the system, which possess a very rich dynamical and geometric structure. In particular, the associated invariant sets play a leading role in determining the global dynamics of the system. This book provides a comprehensive introduction to Mather’s theory, and can serve as an interdisciplinary bridge for researchers and students from different fields seeking to acquaint themselves with the topic.
Starting with the mathematical background from which Mather’s theory was born, Alfonso Sorrentino first focuses on the core questions the theory aims to answer—notably the destiny of broken invariant KAM tori and the onset of chaos—and describes how it can be viewed as a natural counterpart of KAM theory. He achieves this by guiding readers through a detailed illustrative example, which also provides the basis for introducing the main ideas and concepts of the general theory. Sorrentino then describes the whole theory and its subsequent developments and applications in their full generality.
Shedding new light on John Mather’s revolutionary ideas, this book is certain to become a foundational text in the modern study of Hamiltonian systems.
Alfonso Sorrentino is associate professor of mathematics at the University of Rome "Tor Vergata" in Italy. He holds a PhD in mathematics from Princeton University
QUANTITATIVE STATISTICAL STABILITY AND LINEAR RESPONSE FOR IRRATIONAL ROTATIONS AND DIFFEOMORPHISMS OF THE CIRCLE
No full textWe prove quantitative statistical stability results for a large class of small C0 perturbations of circle diffeomorphisms with irrational rotation numbers. We show that if the rotation number is Diophantine the invariant measure varies in a Hölder way under perturbation of the map and the Hölder exponent depends on the Diophantine type of the rotation number. The set of admissible perturbations includes the ones coming from spatial discretization and hence numerical truncation. We also show linear response for smooth perturbations that preserve the rotation number, as well as for more general ones. This is done by means of classical tools from KAM theory, while the quantitative stability results are obtained by transfer operator techniques applied to suitable spaces of measures with a weak topology
Vertebral prosthesis
No full textIl brevetto descrive una nuova protesi vertebrale custom made altamente porosa e leggera, in metamateriale auxetico biocompatibile, realizzata in titanio tramite un processo di manifattura additiva ottimizzato, ed impiegabile come elemento di sostituzione ossea in ambito oncologico a seguito di un intervento di vertebrectomia totale
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