BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-2293 DTSTART:20111028T190000Z DURATION:PT1H0M0S DTSTAMP:20260416T232058Z LAST-MODIFIED:20111025T141858Z LOCATION:Chamberlin 5280 SUMMARY:Phenomenology of a pseudoscalar inflaton: naturally large non- gaussianity\, Theory Seminar (High Energy/Cosmology)\, Marco Peloso\, University of Minnesota DESCRIPTION:More than 20 years ago\, it has been noted that pseudoscal ar axions are one of the best candidates for the inflaton field\, sinc e the flatness of their potential is protected against radiative corre ctions by a shift symmetry. Axions have a specific coupling to gauge f ields\; however\, such coupling has so far received little attention i n connection to inflation. We show that this coupling can actually dra stically change the phenomenological predictions of the most straightf orward realizations of axion inflation. The signatures in the CMB anis otropies are highly distinctive and promising: a specific and large no n-gaussianity of (nearly) equilateral shape\, in addition to detectabl y large spectral tilt and gravity waves. The same coupling can also le ad to observable gravitational waves at interferometers as Advanced LI GO/VIRGO. The current bounds on non-gaussianity imply that the couplin g of a pseudo-scalar inflaton to any gauge field must be smaller than about 1/10^{16} GeV\; this limit is about 5 orders of magnitude strong er than the analogous limit for the coupling of the QCD axion to photo ns.
URL:https://www.physics.wisc.edu/events/?id=2293 END:VEVENT END:VCALENDAR