cherubino

An integrable billiard close to an ellipse of small eccentricity is an ellipse – Jacopo De Simoi (University of Toronto)

In 1927 G. Birkhoff conjectured that if a billiard in a strictly convex smoothdomain is integrable, the domain has to be an ellipse (or a circle). Theconjecture is still wide open, and presents remarkable relations with openquestions in inverse…

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Fibrazioni ellittiche di varieta’ di Calabi-Yau 3folds, algebre di Lie e rappresentazioni collegate – Antonella Grassi (University of Pennsylvania)

I punti doppi razionali, (singolarita’ di Klein o du Val) sono classificati da diagrammi di Dynkin di certe algebre di Lie; queste sono anche le singolarita’ dei modelli di Weierstrass di superfici ellittiche. La struttura di algebra di Lie si…

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Liouville integrability: an effective Morales-Ramis-Simo theorem – Thomas Dreyfus (Institut de Mathématiques de Toulouse)

Morales-Ramis theorem roughly states as follows: Given an Hamiltonian system, we may linearize it to obtain the variational equation. Then, we associate to the variational equation a group, the differential Galois group. Morales and Ramis have…

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