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SUMMARY:Resonant non-Gaussianity - Enrico Pajer\, Cornell
DTSTART:20100514T120000Z
DTEND:20100514T130000Z
UID:TALK24131@talks.cam.ac.uk
CONTACT:James Fergusson
DESCRIPTION:Two of the most exciting observables in the cosmic microwave b
 ackground (CMB) radiation\, which could deeply impact our picture of the e
 arly universe\, are non-Gaussianity and tensor modes. A potential detectio
 n of tensor modes can be explained in terms of a model of large field infl
 ation. Theoretical considerations suggest that a symmetry should be invoke
 d in order to protect the flatness of the inflaton potential and hence an 
 axion enjoying a shift symmetry is a natural candidate. As main example\, 
 I will present a model of inflation in string theory based on axion monodr
 omy. Non-perturbative effects typically correct the axion potential leadin
 g to small sinusoidal modulations on top of an otherwise flat slow roll po
 tential. It can be shown analytically that a resonance between the oscilla
 tions of the background and the oscillations of the curvature fluctuations
  is responsible for the production of an observably large non-Gaussian sig
 nal. An explicit expression for the shape of this resonant non-Gaussianity
  is presented. There is essentially no overlap between this shape and the 
 local\, equilateral\, and orthogonal shapes\, and in fact resonant non-Gau
 ssianity is not captured by the simplest version of the effective field th
 eory of inflation. Hopefully the analytic expression for resonant non-Gaus
 sianity will be useful to further observationally constrain this class of 
 models.
LOCATION:Pavilion B Potter Room (B1.19)
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