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Mathematical Center in Akademgorodok and the Chair of Geometry and Topology invite you to participate in an online seminar "Geometry, topology and their applications". Head of the seminar 鈥� I. A. Taimanov.

The seminar will take place on November 30 at 2 pm (UTC+7). S. V. Ivanov (PDMI, Saint Petersburg) will present his talk "Positive metric entropy in nearly integrable Hamiltonian systems".

The celebrated Kolmogorov-Arnold-Moser (KAM) theorem asserts that a small perturbation of a non-degenerate integrable Hamiltonian system preserves the quasi-periodicity of trajectories and invariant tori on a set of large measure. The question remains: how chaotic the system's behavior can be on the remaining "small" set? I will speak on a recent result of Dima Burago, Dong Chen and myself saying that every integrable system can be perturbed so that the resulting Hamiltonian system has positive measure-theoretic entropy.

In order to participate, you should connect to the Zoom conference a few minutes prior to the start of the seminar via the following link:  or manually in the Zoom app using the conference ID 970 9915 5239 and the password 653845.

Please pay attention to the following rules for conducting an Internet seminar:

• Please, use your real first and last name
• Keep your microphone off during the talk
• Should you have any questions, ask them in the chat