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October 4, 2017 By bruno

Reto Buzano to speak in geometry seminar, 5th December

Reto Buzano (Queen Mary University, London) will speak in the geometry seminar on the 5th December. The talk will take place in the Salle de Profs (9th floor, NO) at 13.30pm. His title is “The moduli spaces of two-convex embedded spheres and tori” and the abstract is below.

It is interesting to study the topology of the space of smoothly embedded n-spheres in R^{n+1}. By Smale’s theorem, this space is contractible for n=1 and by Hatcher’s proof of the Smale conjecture, it is also contractible for n=2. These results are of great importance, generalising in particular the Schoenflies theorem and Cerf’s theorem. In this talk, I will explain how mean curvature flow with surgery can be used to study a higher-dimensional variant of these results, proving in particular that the space of two-convex embedded spheres is path-connected in every dimension n. We then also look at the space of two-convex embedded tori where the question is more intriguing and the result in particular depends on the dimension n. This is all joint work with Robert Haslhofer and Or Hershkovits.

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Département de mathématiques
Université libre de Bruxelles CP 218
Boulevard du Triomphe, Bruxelles 1050,
Belgium

Getting here

The department of mathematics is in building NO, on the Campus de la Plaine, of the Université libre de Bruxelles. The geometry group is on the 7th floor. This page has a map of the campus as well as information on how to reach it via public transport. See the STIB website for more information on public transport in Brussels.

Image credits

Polished ammonite fossil, by Kara Stenberg, Creative Commons licence CC BY-NC 2.0.

Model of 3D projection of a 120-cell, by Edmund Harriss.

The root system of the exceptional Lie algebra E8. By Jared Tarbell, Creative Commons Licence CC BY 2.0.

Getting here

The department of mathematics is in building NO, on the Campus de la Plaine, of the Université libre de Bruxelles. The geometry group is on the 7th floor. This map shows NO, as well as the metro station Delta and entrance 2, which is right by the stop for the number 71 and 72 buses. The number 95 also stops a short walk from the department. See the STIB website for more information on public transport in Brussels.

Image credits

Polished ammonite fossil, by Kara Stenberg, Creative Commons licence CC BY-NC 2.0.

Model of 3D projection of a 120-cell, by Edmund Harriss.

The root system of the exceptional Lie algebra E8. By Jared Tarbell, Creative Commons Licence CC BY 2.0.

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