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CATEGORIES:Theoretical Physics Colloquium
SUMMARY:Shadows and Soft Exchange in Celestial CFT - Danie
l Kapec\, Harvard University
DTSTART;TZID=Europe/London:20211117T141500
DTEND;TZID=Europe/London:20211117T151500
UID:TALK164446AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/164446
DESCRIPTION:I will discuss exponentiated soft exchange in (d+2
)-dimensional gauge and gravitational theories usi
ng the celestial CFT formalism. These models exhib
it spontaneously broken asymptotic symmetries gene
rated by gauge transformations with non-compact su
pport\, and the effective dynamics of the associat
ed Goldstone “edge” mode is expected to be d-dimen
sional. The introduction of an infrared regulator
also explicitly breaks these symmetries so the edg
e mode in the regulated theory is really a d-dimen
sional pseudo-Goldstone boson. Symmetry considerat
ions determine the leading terms in the effective
action\, whose coefficients are controlled by the
infrared cutoff. Computations in this model reprod
uce the abelian infrared divergences in d=2\, and
capture the re-summed (infrared finite) soft excha
nge in higher dimensions. The model also reproduce
s the leading soft theorems in gauge and gravitati
onal theories in all dimensions. Interestingly\, w
e find that it is the shadow transform of the Gold
stone mode that has local d-dimensional dynamics:
the effective action expressed in terms of the Gol
dstone mode is non-local for d>2. The analysis dem
onstrates that symmetry principles suffice to calc
ulate soft exchange in gauge theory and gravity.
LOCATION:ONLINE - Details to be sent by email
CONTACT:
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