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X-WR-CALNAME:Centre for Mathematical Sciences
X-ORIGINAL-URL:http://math-sciences.org
X-WR-CALDESC:Events for Centre for Mathematical Sciences
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TZOFFSETFROM:+0000
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DTSTART:20170101T000000
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DTSTART;TZID=UTC:20171206T160000
DTEND;TZID=UTC:20171206T170000
DTSTAMP:20211204T231528
CREATED:20170819T083941Z
LAST-MODIFIED:20171106T083240Z
UID:2528-1512576000-1512579600@math-sciences.org
SUMMARY:Markus Fröb (York)
DESCRIPTION:“Gauge-invariant observables in perturbative quantum gravity” \nAbstract: \nIt is well known that the diffeomorphism invariance of gravitational theories makes it impossible to define local and gauge-invariant observables in perturbative (quantum) gravity\, except at linear order. While in flat space one can study the S-Matrix\, which is a gauge-invariant global observable\, no analogue exists in a general curved space. Relational observables (i.e.\, the value of one field at the point where a second field has a prescribed value) are natural candidates for observables in (quantum) gravity\, but they are not local when constructed around flat space or around a cosmological (FLRW) background spacetime due to the high symmetry of the latter. \nWe present two different approaches to this problem: a) correlation functions at fixed geodesic distance\, and b) a construction of invariant coordinates\, for which explicit and fully renormalized results for one-graviton-loop corrections to two-point functions and coupling constants have been obtained.
URL:http://math-sciences.org/event/markus-frob-york/
LOCATION:Room 101\, 2-5 Kirkby Place\, Plymouth\, PL4 6DT\, United Kingdom
CATEGORIES:Seminars,Theoretical Physics
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