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Title: A falsely fat curvaton with an observable running of the spectral tilt

In slow roll inflation, the running of the spectral tilt is generically proportional to the square of the deviation from scale invariance, α{sub s}∝(n{sub s}−1){sup 2}, and is therefore currently undetectable. We present a mechanism able to generate a much larger running within slow roll. The mechanism is based on a curvaton field with a large mass term, and a time evolving normalization. This may happen for instance to the angular direction of a complex field in presence of an evolving radial direction. At the price of a single tuning between the mass term and the rate of change of the normalization, the curvaton can be made effectively light at the CMB scales, giving a spectral tilt in agreement with observations. The lightness is not preserved at later times, resulting in a detectable running of the spectral tilt. This mechanism shows that fields with a large mass term do not necessarily decouple from the inflationary physics, and provides a new tool for model building in inflation.
Authors:
 [1] ;  [2] ;  [3]
  1. School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 (United States)
  2. Department of Physics, University of Massachusetts, Amherst, MA 01003 (United States)
  3. Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)
Publication Date:
OSTI Identifier:
22375948
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BUILDINGS; COSMOLOGICAL INFLATION; COSMOLOGICAL MODELS; SCALE INVARIANCE; SIMULATION; TUNING