BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//INFN-LNF - ECPv5.14.2.1//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:INFN-LNF
X-ORIGINAL-URL:https://w3.lnf.infn.it
X-WR-CALDESC:Eventi per INFN-LNF
BEGIN:VTIMEZONE
TZID:Europe/Rome
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20160327T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20161030T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20160914T110000
DTEND;TZID=Europe/Rome:20160914T123000
DTSTAMP:20260422T075732
CREATED:20171026T122715Z
LAST-MODIFIED:20171026T122715Z
UID:6937-1473850800-1473856200@w3.lnf.infn.it
SUMMARY:Probabilities and signalling in quantum field theory
DESCRIPTION:We present an approach to computing probabilities in quantum field theory for a wide class of source-detector models. The approach works directly with probabilities and not with squared matrix elements\, and the resulting probabilities can be written in terms of expectation values of nested commutators and anticommutators. We present results that help in the evaluation of these\, including an expression for the vacuum expectation values of general nestings of commutators and anticommutators in scalar field theory. This approach allows one to see clearly how faster-than-light signalling is prevented\, because it leads to a diagrammatic expansion in which the retarded propagator plays a prominent role. We illustrate the formalism using the simple case of the much-studied Fermi two-atom problem.
URL:/event/probabilities-and-signalling-in-quantum-field-theory/
LOCATION:Aula Seminari\, Via Enrico Fermi\, 40\, Frascati\, Roma\, 00044\, Italia
CATEGORIES:Seminari teorici
END:VEVENT
END:VCALENDAR