Lagrangian theory of integrable systems (Yuri B. Suris, Technische Universität Berlin)

10.10.2017 15:00 – 17:00

We will discuss the notion of a pluri-Lagrangian structure, which should be understood as an analog of integrability for variational systems. This is a development along the line of research of discrete integrable Lagrangian systems initiated about a decade ago, however having its more remote roots in the theory of pluriharmonic functions, in the Z-invariant models of statistical mechanics and their quasiclassical limit, as well as in the theory of variational symmetries going back to E. Noether. We will discuss main features of pluri-Lagrangian systems in dimensions 1 and 2, both continuous and discrete, along with the relations of this novel structure to more standard notions of integrability. We will also consider some applications of this structure, including the classical billiards in quadrics and the problem of commutativity of multi-valued maps (correspondences).

Lieu

Bâtiment: Battelle

Séminaire "Groupes de Lie et espaces des modules"

entrée libre