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DTSTART:19700329T010000
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CATEGORIES:Quantum Fields and Strings Seminars
SUMMARY:Rigorous bounds on Einstein--Maxwell theory and th
e Black Hole Weak Gravity Conjecture - Johan Henri
ksson (Pisa)
DTSTART;TZID=Europe/London:20220505T130000
DTEND;TZID=Europe/London:20220505T140000
UID:TALK173270AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/173270
DESCRIPTION:In this talk I will discuss positivity bounds on t
he effective field theory (EFT) of photons\, deriv
ed from dispersion relations and the generalised o
ptical theorem. In general\, basic assumptions on
the high-energy UV completion\, such as unitarity
and partial wave decomposition\, imply bounds on t
he space of the Wilson coefficients parametrising
the low-energy EFT. We develop a method that allow
s us to bound Wilson coefficients appearing in amp
litudes of all possible polarisations\, not just t
he forward amplitudes. In the absence of dynamical
gravity\, such bounds imply a set of inequalities
known as the Black Hole Weak Gravity Conjecture (
WGC). However\, in the presence of dynamical gravi
ty\, we find that the dispersion relation argument
alone cannot rule out a small violations of the B
lack Hole WGC\, and we determine the maximum allow
ed size of such violations.
LOCATION:Potter Room\, DAMTP
CONTACT:Chiung Hwang
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