[Todos CMAT] Mañana Lucas Ambrozio (IMPA) en salón Marrón de Fing

[santiago.martinchich en fcea.edu.uy]

Hola,

Notar el cambio de salón. Mañana jueves 21/03 a las 17:00 en el Salón 
Marrón (705) tendremos una sesión extraordinaria del Seminario de 
Dinámica.

Expositor: Lucas Ambrozio (IMPA)

Título: The width of embedded circles

Resumen: Width is a classical geometric invariant of plane curves. It 
measures how narrow they are. Its definition, however, is based on 
Euclidean geometry and not easily generalisable beyond other constant 
curvature spaces. We will discuss how the variational theory of the 
Riemannian distance function, developed along the lines of 
Lusternik-Schnirelmann theory, can be used to define a meaningful notion 
of width for curves embedded in any complete Riemannian manifold, of any 
dimension. In particular, this definition allow to generalise another 
classical notion - curves of constant width - and to prove the existence 
of geodesics that meet two points of the curve in certain geometrically 
special configurations - for instance, in same cases, orthogonally. The 
talk will be based on joint work with Rafael Montezuma (UFC - Fortaleza) 
and Roney Santos (USP - São Paulo).

Saludos,

Luis Pedro y Santiago