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SUMMARY:A Weak Gravity Theorem - Mehrdad Mirbabayi\, ICTP
DTSTART:20190508T131500Z
DTEND:20190508T141500Z
UID:TALK123520@talks.cam.ac.uk
CONTACT:Francesca Chadha-Day
DESCRIPTION:In a gravitational theory with a massless photon the maximum c
 harge-to-mass ratio of black holes approaches the prediction of \nthe Eins
 tein-Maxwell theory as black hole mass increases: Q_ext/M = 1 + a/ M^2 for
  some constant a. I will show that a>0 if \nbelow the quantum gravity scal
 e (\\Lambda) there are many degrees of freedom with a hierarchically small
  mass gap\, log(\\Lambda/m)>>1. \nIn this regime one can derive field-theo
 retic sum-rules for the coefficients of the leading corrections to the Ein
 stein-Maxwell theory \nthat imply a>0. Hence gravitational force among max
 imally charged black holes keeps getting weaker with respect to the electr
 ic force as \nthe black hole size becomes smaller.
LOCATION:MR2\, Centre for Mathematical Sciences
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