Theoretical Particle Physics and Cosmology Seminar – Niels Bohr Institute - University of Copenhagen

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Theoretical Particle Physics and Cosmology Seminar

Speaker: H. Collins, NBI

Title: Effective theory approaches to the trans-Planckian problem

Abstract: This talk begins with a review of the inflationary
picture, describing how it provides a mechanism for generating tiny
fluctuations throughout the universe that over time collapse into the
structures we see today.  This mechanism relies on two basic
ingredients---an early era of accelerated expansion of the universe
and the presence of a quantum field.  If this era lasted sufficiently
long, then the structures today would have had their origin in
quantum fluctuations that were once smaller than a Planck-length.
This observation corresponds to the "trans-Planckian" problem of
inflation.  We discuss a few of the approaches for addressing this
problem and what they imply for future cosmological observations.