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SUMMARY:Invariant geometry of gravitational waves
DTSTART;VALUE=DATE-TIME:20200918T120000Z
DTEND;VALUE=DATE-TIME:20200918T130000Z
DTSTAMP;VALUE=DATE-TIME:20220116T225442Z
UID:indico-event-6039@indico.math.cnrs.fr
DESCRIPTION:The existence of gravitational waves is one of the prediction\
, now empirically validated\, of Einstein's General Relativity. The underl
ying mathematical model for this predication is a class of Einstein Lorent
zian manifolds dubbed "Asymptotically flat space-times". These are particu
lar case of conformally compact manifolds\, the presence of gravitational
waves being geometrically encoded in their asymptotics (i.e at the conform
al boundary).\n\nI will review some of the definitions and classical resul
ts associated to asymptotically flat-space times: with an emphasis on th
e intertwined aspects of both geometry and physics. I will then show how a
generalisation of the tractor calculus from conformal geometry can be use
d to invariantly and intrinsically encode gravitational radiations as an "
extra" layer of geometry at the conformal boundary: they amounts to a choi
ce of Tractor connection (these are a particular case of Cartan connection
s). More precisely\, a non-vanishing tractor curvature correspond to the p
resence of gravitational radiations while the moduli space of flat connect
ions is physically associated to the so-called "degeneracy of gravity vacu
a".\n\nhttps://indico.math.cnrs.fr/event/6039/
LOCATION:Bât E2 1180
URL:https://indico.math.cnrs.fr/event/6039/
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