BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Phase space singularities of nonlinear field theories: interaction
  of gauge symmetries\, conservation laws and topology
DTSTART:20251128T130000Z
DTEND:20251128T140000Z
DTSTAMP:20260504T051500Z
UID:indico-event-15400@indico.math.cnrs.fr
CONTACT:kellendonk@math.univ-lyon1.fr\;athomas@math.univ-lyon1.fr
DESCRIPTION:Speakers: Igor Khavkine (Prague)\n\nA classical field theory i
 s often described by a non-linear PDEs with gauge symmetries. Its space of
  solutions\, endowed with a suitable (typically infinite dimensional) diff
 erential as well as symplectic/Poisson structures\, constitutes the theory
 's phase space. The phase space is a central object in the geometric appro
 ach to field theory as a mechanical system and to its quantization. As for
  any nonlinear system\, the space of solutions can fail to be a smooth man
 ifold\, typically featuring conical singularities along a singular locus. 
 In this context\, the solutions belonging to this singular locus are calle
 d "linearization unstable". Early explicit examples from General Relativit
 y noted that such solutions require the simultaneous existence of some non
 -trivial symmetries and topological conditions (e.g.\, compactness). I wil
 l use a general geometric approach to PDEs to identify such "linearization
  instabilities" and show how they are associated to certain cohomology cla
 sses\, naturally explaining the previous observations. Based on Ann. Henri
  Poincaré 16\, 255–288 (2015). https://doi.org/10.1007/s00023-014-0321-
 9\n\nhttps://indico.math.cnrs.fr/event/15400/
LOCATION:Fokko du Cloux (Bat. Braconnier)
URL:https://indico.math.cnrs.fr/event/15400/
END:VEVENT
END:VCALENDAR