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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:1
UID:UW-Physics-Event-5155
DTSTART:20190821T190000Z
DTEND:20190821T201500Z
DTSTAMP:20210301T073910Z
LAST-MODIFIED:20190820T211453Z
LOCATION:5280 Chamberlin
SUMMARY:Quantum non-linear evolution of inflationary tensor perturbati
ons\, Theory Seminar (High Energy/Cosmology)\, Jinn-Ouk Gong\, KASI
DESCRIPTION:We study the quantum mechanical evolution of the tensor pe
rturbations during inflation with non-linear tensor interactions. We f
irst obtain the Lindblad terms generated by non-linear interactions by
tracing out unobservable sub-horizon modes. Then we calculate explici
tly the reduced density matrix for the super-horizon modes\, and show
that the probability of maintaining the unitarity of the squeezed stat
e decreases in time. The decreased probability is transferred to other
elements of the reduced density matrix including off-diagonal ones\,
so the evolution of the reduced density matrix describes the quantum-t
o-classical transition of the tensor perturbations. This is different
from the classicality accomplished by the squeezed state\, the suppres
sion of the non-commutative effect\, which is originated from the quad
ratic\, linear interaction\, and also maintains the unitarity. The qua
ntum-to-classical transition occurs within 5 - 10 e-folds\, faster tha
n the curvature perturbation.
URL:https://www.physics.wisc.edu/events/?id=5155
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