Lagrangian relations and linear point billiards

Beitrag in einer Fachzeitschrift

Details zur Publikation

Autorinnen und Autoren: Féjoz J, Knauf A, Montgomery R
Zeitschrift: Nonlinearity
Jahr der Veröffentlichung: 2017
Band: 30
Heftnummer: 4
Seitenbereich: 1326-1355
ISSN: 0951-7715


Motivated by the high-energy limit of the N-body problem we construct non-deterministic billiard process. The billiard table is the complement of a finite collection of linear subspaces within a Euclidean vector space. A trajectory is a constant speed polygonal curve with vertices on the subspaces and change of direction upon hitting a subspace governed by 'conservation of momentum' (mirror reflection). The itinerary of a trajectory is the list of subspaces it hits, in order. (A) Are itineraries finite? (B) What is the structure of the space of all trajectories having a fixed itinerary? In a beautiful series of papers Burago-Ferleger-Kononenko [BFK] answered (A) affirmatively by using non-smooth metric geometry ideas and the notion of a Hadamard space. We answer (B) by proving that this space of trajectories is diffeomorphic to a Lagrangian relation on the space of lines in the Euclidean space. Our methods combine those of BFK with the notion of a generating family for a Lagrangian relation.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Knauf, Andreas Prof. Dr.
Lehrstuhl für Mathematik (Mathematische Physik)

Einrichtungen weiterer Autorinnen und Autoren

University of California Santa Cruz
University of Paris 9 - Paris-Dauphine / Université Paris 9 Paris-Dauphine


Féjoz, J., Knauf, A., & Montgomery, R. (2017). Lagrangian relations and linear point billiards. Nonlinearity, 30(4), 1326-1355.

Féjoz, Jacques, Andreas Knauf, and Richard Montgomery. "Lagrangian relations and linear point billiards." Nonlinearity 30.4 (2017): 1326-1355.


Zuletzt aktualisiert 2019-22-01 um 14:10